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Nafi'an MRT, Sabirin RM, Wibowo RA, Sofyana M, Zahra IH, Wiryawan DA, Wijayatno QJ, Rohman A. Effect of nitrate supplementation on oxygen saturation levels for acute mountain sickness prevention: A systematic review and meta-analysis. Nitric Oxide 2024; 150:27-36. [PMID: 39002891 DOI: 10.1016/j.niox.2024.07.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Revised: 05/27/2024] [Accepted: 07/04/2024] [Indexed: 07/15/2024]
Abstract
PURPOSE This study aimed to systematically review the effect of nitrate supplementation on blood oxygen saturation. METHODS We searched PubMed, Scopus, and Cochrane Library databases from their inception up to October 2022. Two reviewers independently conducted two stages of the screening process to include a randomized controlled trial with nitrate supplementation versus placebo intervention assessing oxygen saturation among lowlanders going to either real or simulated high altitude environments. We used the Cochrane Risk of Bias 2.0 tool to assess the risk of bias in the included studies. Fixed-effect model meta-analyses were conducted for laboratory-based studies. Random-effect meta-analyses were conducted for real-world studies. RESULTS We found 7 trials that met the eligibility criteria. A meta-analysis of studies with some bias concerns showed an increase of 1.26 % in the SpO2 with 44 % I2 during submaximal exercise at simulated high altitudes (GRADE: low). On the contrary, a meta-analysis of studies without heterogeneity showed that nitrate supplementation aggravated oxygen saturation decline (-2.64 %, p = 0.03, GRADE: high) during rest in real high-altitude environments. A meta-analysis also showed that nitrate supplementation did not affect Acute Mountain Sickness (AMS) symptoms (GRADE: high). CONCLUSION Our results suggest that nitrate supplementation did not provide benefits for AMS prevention during rest at high altitudes. The low-quality evidence showing small beneficial effects of nitrate supplementation during exercise calls for further studies.
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Affiliation(s)
| | - Rahmaningsih Mara Sabirin
- Department of Physiology, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Jakarta, Indonesia.
| | - Rakhmat Ari Wibowo
- Department of Physiology, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Jakarta, Indonesia; Physical Activity for Health Research Centre, Institute of Sport, Physical Education, and Health Sciences, Moray House School of Education and Sport, University of Edinburgh, Edinburgh, UK
| | - Meida Sofyana
- Department of Physiology, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Jakarta, Indonesia; School of Physiology, Pharmacology, & Neuroscience, University of Bristol, Bristol, England, UK
| | - Imtiyaz Hafizah Zahra
- School of Medicine, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Indonesia
| | - Danindra Ario Wiryawan
- School of Medicine, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Indonesia
| | - Qonita Jayanti Wijayatno
- School of Medicine, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Indonesia
| | - Abdul Rohman
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Universitas Gadjah Mada, Yogyakarta, 55281, Indonesia
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Kang Y, Dillon KN, Martinez MA, Maharaj A, Fischer SM, Figueroa A. L-Citrulline Supplementation Improves Arterial Blood Flow and Muscle Oxygenation during Handgrip Exercise in Hypertensive Postmenopausal Women. Nutrients 2024; 16:1935. [PMID: 38931289 PMCID: PMC11206967 DOI: 10.3390/nu16121935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Revised: 06/07/2024] [Accepted: 06/16/2024] [Indexed: 06/28/2024] Open
Abstract
Endothelial dysfunction decreases exercise limb blood flow (BF) and muscle oxygenation. Acute L-Citrulline supplementation (CIT) improves muscle tissue oxygen saturation index (TSI) and deoxygenated hemoglobin (HHb) during exercise. Although CIT improves endothelial function (flow-mediated dilation [FMD]) in hypertensive women, the impact of CIT on exercise BF and muscle oxygenation (TSI) and extraction (HHb) are unknown. We examined the effects of CIT (10 g/day) and a placebo for 4 weeks on blood pressure (BP), arterial vasodilation (FMD, BF, and vascular conductance [VC]), and forearm muscle oxygenation (TSI and HHb) at rest and during exercise in 22 hypertensive postmenopausal women. Compared to the placebo, CIT significantly (p < 0.05) increased FMD (Δ-0.7 ± 0.6% vs. Δ1.6 ± 0.7%) and reduced aortic systolic BP (Δ3 ± 5 vs. Δ-4 ± 6 mmHg) at rest and improved exercise BF (Δ17 ± 12 vs. Δ48 ± 16 mL/min), VC (Δ-21 ± 9 vs. Δ41 ± 14 mL/mmHg/min), TSI (Δ-0.84 ± 0.58% vs. Δ1.61 ± 0.46%), and HHb (Δ1.03 ± 0.69 vs. Δ-2.76 ± 0.77 μM). Exercise BF and VC were positively correlated with improved FMD and TSI during exercise (all p < 0.05). CIT improved exercise artery vasodilation and muscle oxygenation via increased endothelial function in hypertensive postmenopausal women.
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Affiliation(s)
- Yejin Kang
- Department of Kinesiology and Sport Management, Texas Tech University, Lubbock, TX 79409, USA; (Y.K.); (K.N.D.); (M.A.M.)
| | - Katherine N. Dillon
- Department of Kinesiology and Sport Management, Texas Tech University, Lubbock, TX 79409, USA; (Y.K.); (K.N.D.); (M.A.M.)
| | - Mauricio A. Martinez
- Department of Kinesiology and Sport Management, Texas Tech University, Lubbock, TX 79409, USA; (Y.K.); (K.N.D.); (M.A.M.)
| | - Arun Maharaj
- Department of Epidemiology and Cancer Control, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA;
| | - Stephen M. Fischer
- Department of Family and Community Medicine, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA;
| | - Arturo Figueroa
- Department of Kinesiology and Sport Management, Texas Tech University, Lubbock, TX 79409, USA; (Y.K.); (K.N.D.); (M.A.M.)
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Yu CJ, Tsai SC, Liao YH, Chen CY, Wu KC. Exploring the Potential Benefits of Interventions When Addressing Simulated Altitude Hypoxia during Male Cyclist Sports: A Systematic Review. APPLIED SCIENCES 2024; 14:3091. [DOI: 10.3390/app14073091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/21/2024]
Abstract
Training in hypoxic environments enhances endurance, but the various influences of training protocols and supplementation for efficient performance are not yet clear. This systematic review explored the effects of different supplementations and interventions used to optimize the aerobic and anaerobic performance of cyclists. Data were collected from the following sources: PubMed, Google Scholar, EMBASE, WOS, Cochrane Central Register of Controlled Trials, and randomized controlled trials (RCTs). Studies that explored the effects of supplementation or intervention during cycling were selected for analysis. Five studies (67 male cyclists; mean age, 23.74–33.56 years) reported different outcomes from supplementation or intervention during the acute hypoxia of cyclists. Three studies (42 male cyclists; mean age, 25.88–36.22 years) listed the benefits of beetroot juice in preserving SpO2 (pulse oxygen saturation) and enhancing high-intensity endurance performance, effectively preventing the reduction in power output. This systematic review provided evidence that the different effects of ischemic preconditioning (IPC), sildenafil, and beetroot (BR) supplementation and intervention did not present a statistically greater benefit than for normoxia groups, but BR supplementation promoted the benefits of SpO2. Future research should evaluate the duration and higher FiO2 (simulated altitude, hypoxia) levels of hypoxia in training protocols for cyclists. This is important when determining the effectiveness of supplements or interventions in hypoxic conditions and their impact on sports performance, particularly in terms of power output.
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Affiliation(s)
- Chen-Jui Yu
- Institute of Sports Sciences, University of Taipei, Taipei City 11153, Taiwan
| | - Shiow-Chwen Tsai
- Institute of Sports Sciences, University of Taipei, Taipei City 11153, Taiwan
| | - Yi-Hung Liao
- Department of Exercise and Health Sciences, National Taipei University of Nursing and Health Sciences, Taipei City 11219, Taiwan
| | - Chung-Yu Chen
- Department of Exercise and Health Sciences, University of Taipei, Taipei City 11153, Taiwan
| | - Kuo-Cheng Wu
- Graduate Institute of Sports Training, Kinesiology, University of Taipei, Taipei City 11153, Taiwan
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4
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Giv V, Aminaei M, Nikoei R. The effect of eight weeks beetroot juice supplement on aerobic, anaerobic power, and field performance of soccer players. Res Sports Med 2024; 32:132-144. [PMID: 35726852 DOI: 10.1080/15438627.2022.2090250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Accepted: 06/07/2022] [Indexed: 10/18/2022]
Abstract
The purpose of the study investigated the effect of eight weeks of soccer training with beetroot juice supplement on aerobic power, anaerobic power, and field performance of soccer players. This is experimental research, by the control group in pre and post-test. The statistical population was male soccer players. Forty subjects were randomly divided into four groups including the exercise group (EX) the exercise group with beetroot juice supplement (EX&BRJS) the beetroot juice supplement group (BRJS), and the control group (C). Aerobic power, anaerobic threshold, and respiratory exchange ratio, measured by the gas analyser (Cosmed), anaerobic power (peak, mean power), and fatigue index, by Wingate cycle test (Monark, 839), and field performance by (Bangsbo, field test performance). The statistical methods include the Kolmogorov-Smirnov, Levin, covariance (ANCOVA), and pair comparison with Bonferroni test. The results showed eight weeks' of soccer training with beetroot juice supplement, significantly changed aerobic power, respiratory exchange ratio, anaerobic threshold, anaerobic power, field performance, and fatigue index (P ≤ 0.05). Additionally, in all variables, the paired comparison showed that the EX&BRJS group progressed more than all other condition groups. The soccer athletes may use beetroot juice supplements along with soccer exercises to improve aerobic and anaerobic power and field performance.
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Affiliation(s)
- Vahid Giv
- Department of Sport Sciences, The Shahid Bahonar University of Kerman, Kerman, IRAN
| | - Mohsen Aminaei
- Department of Sport Sciences, The Shahid Bahonar University of Kerman, Kerman, IRAN
| | - Rohullah Nikoei
- Department of Sport Sciences, The Shahid Bahonar University of Kerman, Kerman, IRAN
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Banaei P, Tadibi V, Amiri E, Machado DGDS. Concomitant dual-site tDCS and dark chocolate improve cognitive and endurance performance following cognitive effort under hypoxia: a randomized controlled trial. Sci Rep 2023; 13:16473. [PMID: 37777571 PMCID: PMC10542360 DOI: 10.1038/s41598-023-43568-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 09/26/2023] [Indexed: 10/02/2023] Open
Abstract
Ten male cyclists were randomized into four experimental conditions in this randomized, cross-over, double-blind, and sham-controlled study to test the combined effect of acute dark chocolate (DC) ingestion and anodal concurrent dual-site transcranial direct current stimulation (a-tDCS) targeting M1 and left DLPFC on cognitive and whole-body endurance performance in hypoxia after performing a cognitive task. Two hours before the sessions, chocolate was consumed. After arriving at the lab, participants completed an incongruent Stroop task for 30 min in hypoxia (O2 = 13%) to induce mental fatigue, followed by 20 min of tDCS (2 mA) in hypoxia. Then, in hypoxia, they performed a time-to-exhaustion task (TTE) while measuring physiological and psychophysiological responses. Cognitive performance was measured at baseline, after the Stroop task, and during and after TTE. TTE in 'DC + a-tDCS' was significantly longer than in 'white chocolate (WC) + a-tDCS' and WC + sham-tDCS'. The vastus medialis muscle electromyography amplitude was significantly higher in 'DC + a-tDCS' and 'DC + sham-tDCS' than in 'WC + sh-tDCS'. During and after the TTE, choice reaction time was significantly lower in 'DC + a-tDCS' compared to 'WC + sh-tDCS'. Other physiological or psychophysiological variables showed no significant differences. The concurrent use of acute DC consumption and dual-site a-tDCS might improve cognitive and endurance performance in hypoxia.
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Affiliation(s)
- Parisa Banaei
- Exercise Metabolism and Performance Lab (EMPL), Department of Exercise Physiology, Faculty of Sport Sciences, Razi University, University Avenue, Taq-e Bostan, Kermanshah, 6714414971, Iran
| | - Vahid Tadibi
- Exercise Metabolism and Performance Lab (EMPL), Department of Exercise Physiology, Faculty of Sport Sciences, Razi University, University Avenue, Taq-e Bostan, Kermanshah, 6714414971, Iran.
| | - Ehsan Amiri
- Exercise Metabolism and Performance Lab (EMPL), Department of Exercise Physiology, Faculty of Sport Sciences, Razi University, University Avenue, Taq-e Bostan, Kermanshah, 6714414971, Iran
| | - Daniel Gomes da Silva Machado
- Research Group in Neuroscience of Human Movement (NeuroMove), Department of Physical Education, Federal University of Rio Grande do Norte, Natal, RN, 59078-970, Brazil
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McMahon NF, Brooker PG, Kadach S, Pavey TG, Leveritt MD. Estimating nitrate intake in the Australian diet: Design and validation of a food frequency questionnaire. J Hum Nutr Diet 2023; 36:169-180. [PMID: 35692098 PMCID: PMC10084179 DOI: 10.1111/jhn.13048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 06/07/2022] [Indexed: 01/19/2023]
Abstract
BACKGROUND Dietary nitrates may play a role in mediating several key physiological processes impacting health and/or exercise performance. However, current methods for assessing dietary nitrate (NO3 - ) consumption are inadequate. The present study aimed to examine the dietary nitrate intake in a sample of 50 healthy adults, as well as test the validity of a purposefully developed food frequency questionnaire (FFQ). METHODS Dietary nitrate intake was estimated over a week using (i) three 24-h dietary recalls; (ii) a short-term (7-day) FFQ; and (iii) a biomarker (urinary nitrate), in conjunction with a nitrate reference database. RESULTS Daily dietary nitrate intake estimates were 130.94 mg (average of three 24-h recalls) and 180.62 mg (FFQ). The mean urinary NO3 - excretion was 1974.79 µmol day-1 (or 917.9 µmol L-1 ). Despite the difference between the two dietary assessment methods, there was a moderate positive correlation (r = 0.736, ρ < 0.001) between the two tools. There was also a positive correlation between urinary NO3 - and 24-h recall data (r = 0.632, ρ < 0.001), as well as between urinary NO3 - and FFQ (r = 0.579, ρ < 0.001). CONCLUSIONS The ability to accurately estimate nitrate intakes depends on having suitable reference methods to estimate the concentrations of nitrate in the food supply, coupled with valid and reliable dietary assessment tools. Based on the findings from the present study, at an individual level, dietary recalls or records may be more accurate in estimating intakes of NO3 - . However, given the lower cost and time needed for administration relative to recalls, the FFQ has merit for estimating NO3 - intakes in health interventions, dietary surveys and surveillance programs.
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Affiliation(s)
- Nicholas F. McMahon
- School of Human Movement and Nutrition SciencesUniversity of QueenslandSt LuciaQLDAustralia
| | - Paige G. Brooker
- School of Human Movement and Nutrition SciencesUniversity of QueenslandSt LuciaQLDAustralia
| | - Stefan Kadach
- School of Sport and Health Sciences, College of Life and Environmental Sciences, St Luke's CampusUniversity of ExeterExeterUK
| | - Toby G. Pavey
- School of Exercise and Nutrition SciencesQueensland University of TechnologyKelvin GroveQLDAustralia
| | - Michael D. Leveritt
- School of Human Movement and Nutrition SciencesUniversity of QueenslandSt LuciaQLDAustralia
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7
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Five Days of Tart Cherry Supplementation Improves Exercise Performance in Normobaric Hypoxia. Nutrients 2023; 15:nu15020388. [PMID: 36678258 PMCID: PMC9864878 DOI: 10.3390/nu15020388] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 01/08/2023] [Accepted: 01/10/2023] [Indexed: 01/15/2023] Open
Abstract
Previous studies have shown tart cherry (TC) to improve exercise performance in normoxia. The effect of TC on hypoxic exercise performance is unknown. This study investigated the effects of 5 days of tart cherry (TC) or placebo (PL) supplementation on hypoxic exercise performance. Thirteen healthy participants completed an incremental cycle exercise test to exhaustion (TTE) under two conditions: (i) hypoxia (13% O2) with PL and (ii) hypoxia with TC (200 mg anthocyanin per day for 4 days and 100 mg on day 5). Pulmonary gas exchange variables, peripheral arterial oxygen saturation (SpO2), deoxygenated hemoglobin (HHb), and tissue oxygen saturation (StO2) assessed by near-infrared spectroscopy in the vastus lateralis muscle were measured at rest and during exercise. Urinary 8-hydro-2′ deoxyguanosine (8-OHdG) excretion was evaluated pre-exercise and 1 and 5 h post-exercise. The TTE after TC (940 ± 84 s, mean ± standard deviation) was longer than after PL (912 ± 63 s, p < 0.05). During submaximal hypoxic exercise, HHb was lower and StO2 and SpO2 were higher after TC than PL. Moreover, a significant interaction (supplements × time) in urinary 8-OHdG excretion was found (p < 0.05), whereby 1 h post-exercise increases in urinary 8-OHdG excretion tended to be attenuated after TC. These findings indicate that short-term dietary TC supplementation improved hypoxic exercise tolerance, perhaps due to lower HHb and higher StO2 in the working muscles during submaximal exercise.
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Abedelmalek S, Aloui K, Boussetta N, Alahmadi B, Zouch M, Chtourou H, Souissi N. Does Opuntia ficus-indica Juice Supplementation Improve Biochemical and Cardiovascular Response to a 6-Minute Walk Test in Type 2 Diabetic Patients? MEDICINA (KAUNAS, LITHUANIA) 2022; 58:1561. [PMID: 36363518 PMCID: PMC9696711 DOI: 10.3390/medicina58111561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Revised: 10/03/2022] [Accepted: 10/06/2022] [Indexed: 11/11/2022]
Abstract
Background and objectives: The purpose of this study was to evaluate the effect of Opuntia ficus-indica juice (OFIJ) on performance and biochemical and physiological responses to a 6 min walking test (6MWT) in diabetic patients. Materials and Methods: Twenty diabetic patients performed a 6MWT at 07:00 h. During each test session, they were asked to drink 70 mL/day of natural OFIJ or placebo (PLA) for 4 days. Results: the results showed that cardiovascular parameters increased significantly after the 6MWT under both conditions. While, cortisol, HbA1c, cholesterol total (CT), triglycerides (TG), as well as low-density lipoprotein (LDL) were not modified between without and with supplementation. Likewise, no significant variation in performance was observed for PLA and OFIJ (p > 0.05). The cardiovascular parameters (heart rate max (HRmax), diastolic blood pressure (DBP), and systolic blood pressure (SBP)), lipid profile (CT, TG, LDL, and high-density lipoprotein HDL), hormonal parameters (insulin and glucagon), HbA1c and lactate ([La]) did not present any significant modification either between PLA or OFIJ (p > 0.05). Muscle-damage markers (creatine kinase (CK) and lactate dehydrogenase (LDH)], cortisol, and liver parameters (i.e., oxidative stress marker, γGT, and total bilirubin) as well as glucose (GLC) were affected by supplementation (p < 0.05) before and after the 6MWT, but this change was significant only for OFIJ (p < 0.05). Conclusion: OFIJ had an antioxidant capacity, improved performance of the 6MWT, and reduced muscle-damage markers and glucose level in type 2 diabetic patients.
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Affiliation(s)
- Salma Abedelmalek
- Laboratory of Physiology and Functional Exploration, Faculty of Medicine, Sousse 4002, Tunisia
- Department of Sport Science and Physical Activity, College of Education, University of Ha’il, Hail 55255, Saudi Arabia
| | - Khouloud Aloui
- Physical Activity, Sport, and Health, UR18JS01, National Observatory of Sport, Tunis 1003, Tunisia
| | - Nesrine Boussetta
- Physical Activity, Sport, and Health, UR18JS01, National Observatory of Sport, Tunis 1003, Tunisia
| | - Bayan Alahmadi
- Department of Sport Science and Physical Activity, College of Education, University of Ha’il, Hail 55255, Saudi Arabia
| | - Mohamed Zouch
- Laboratory of Physiology and Functional Exploration, Faculty of Medicine, Sousse 4002, Tunisia
- Department of Sport Science and Physical Activity, College of Education, University of Ha’il, Hail 55255, Saudi Arabia
| | - Hamdi Chtourou
- Physical Activity, Sport, and Health, UR18JS01, National Observatory of Sport, Tunis 1003, Tunisia
- High Institute of Sport and Physical Education of Sfax, University of Sfax, Sfax 3000, Tunisia
| | - Nizar Souissi
- Physical Activity, Sport, and Health, UR18JS01, National Observatory of Sport, Tunis 1003, Tunisia
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Tan R, Pennell A, Price KM, Karl ST, Seekamp-Hicks NG, Paniagua KK, Weiderman GD, Powell JP, Sharabidze LK, Lincoln IG, Kim JM, Espinoza MF, Hammer MA, Goulding RP, Bailey SJ. Effects of Dietary Nitrate Supplementation on Performance and Muscle Oxygenation during Resistance Exercise in Men. Nutrients 2022; 14:nu14183703. [PMID: 36145080 PMCID: PMC9504620 DOI: 10.3390/nu14183703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Revised: 08/31/2022] [Accepted: 09/05/2022] [Indexed: 11/16/2022] Open
Abstract
The purpose of the current study was to assess the effects of acute and short-term nitrate (NO3−)-rich beetroot juice (BR) supplementation on performance outcomes and muscle oxygenation during bench press and back squat exercise. Fourteen recreationally active males were assigned in a randomized, double-blind, crossover design to supplement for 4 days in two conditions: (1) NO3−-depleted beetroot juice (PL; 0.10 mmol NO3− per day) and (2) BR (11.8 mmol NO3− per day). On days 1 and 4 of the supplementation periods, participants completed 2 sets of 2 × 70%1RM interspersed by 2 min of recovery, followed by one set of repetitions-to-failure (RTF) at 60%1RM for the determination of muscular power, velocity, and endurance. Quadriceps and pectoralis major tissue saturation index (TSI) were measured throughout exercise. Plasma [NO3−] and nitrite ([NO2−]) were higher after 1 and 4 days of supplementation with BR compared to PL (p < 0.05). Quadriceps and pectoralis major TSI were not different between conditions (p > 0.05). The number of RTF in bench press was 5% greater after acute BR ingestion compared to PL (PL: 23 ± 4 vs. BR: 24 ± 5, p < 0.05). There were no differences between BR and PL for RTF for back squat or power and velocity for back squat or bench press (p > 0.05). These data improve understanding on the ergogenic potential of BR supplementation during resistance exercise.
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Affiliation(s)
- Rachel Tan
- Department of Sports Medicine, Pepperdine University, Malibu, CA 90263, USA
- Correspondence: ; Tel.: +1-3105067041
| | - Adam Pennell
- Department of Sports Medicine, Pepperdine University, Malibu, CA 90263, USA
| | - Katherine M. Price
- Department of Sports Medicine, Pepperdine University, Malibu, CA 90263, USA
| | - Sean T. Karl
- Department of Sports Medicine, Pepperdine University, Malibu, CA 90263, USA
| | | | | | - Grant D. Weiderman
- Department of Sports Medicine, Pepperdine University, Malibu, CA 90263, USA
| | - Joanna P. Powell
- Department of Sports Medicine, Pepperdine University, Malibu, CA 90263, USA
| | - Luka K. Sharabidze
- Department of Sports Medicine, Pepperdine University, Malibu, CA 90263, USA
| | | | - Justin M. Kim
- Department of Sports Medicine, Pepperdine University, Malibu, CA 90263, USA
| | | | - Maya A. Hammer
- Department of Sports Medicine, Pepperdine University, Malibu, CA 90263, USA
| | - Richie P. Goulding
- Laboratory for Myology, Faculty of Behavioural and Movement Sciences, Amsterdam Movement Sciences, Vrije Universiteit Amsterdam, 1081 HZ Amsterdam, The Netherlands
| | - Stephen J. Bailey
- School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough LE11 3TU, UK
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Wynne AG, Affourtit C. Nitrite lowers the oxygen cost of ATP supply in cultured skeletal muscle cells by stimulating the rate of glycolytic ATP synthesis. PLoS One 2022; 17:e0266905. [PMID: 35939418 PMCID: PMC9359526 DOI: 10.1371/journal.pone.0266905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 07/05/2022] [Indexed: 11/25/2022] Open
Abstract
Dietary nitrate lowers the oxygen cost of human exercise. This effect has been suggested to result from stimulation of coupling efficiency of skeletal muscle oxidative phosphorylation by reduced nitrate derivatives. In this paper, we report the acute effects of sodium nitrite on the bioenergetic behaviour of cultured rat (L6) myocytes. At odds with improved efficiency of mitochondrial ATP synthesis, extracellular flux analysis reveals that a ½-hour exposure to NaNO2 (0.1–5 μM) does not affect mitochondrial coupling efficiency in static myoblasts or in spontaneously contracting myotubes. Unexpectedly, NaNO2 stimulates the rate of glycolytic ATP production in both myoblasts and myotubes. Increased ATP supply through glycolysis does not emerge at the expense of oxidative phosphorylation, which means that NaNO2 acutely increases the rate of overall myocellular ATP synthesis, significantly so in myoblasts and tending towards significance in contractile myotubes. Notably, NaNO2 exposure shifts myocytes to a more glycolytic bioenergetic phenotype. Mitochondrial oxygen consumption does not decrease after NaNO2 exposure, and non-mitochondrial respiration tends to drop. When total ATP synthesis rates are expressed in relation to total cellular oxygen consumption rates, it thus transpires that NaNO2 lowers the oxygen cost of ATP supply in cultured L6 myocytes.
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Affiliation(s)
- Anthony G. Wynne
- School of Biomedical Sciences, University of Plymouth, Plymouth, United Kingdom
| | - Charles Affourtit
- School of Biomedical Sciences, University of Plymouth, Plymouth, United Kingdom
- * E-mail:
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11
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Hennis PJ, Cumpstey AF, O'Doherty AF, Fernandez BO, Gilbert-Kawai ET, Mitchell K, Moyses H, Cobb A, Meale P, Pöhnl H, Mythen MG, Grocott MPW, Levett DZH, Martin DS, Feelisch M. Dietary Nitrate Supplementation Does Not Alter Exercise Efficiency at High Altitude - Further Results From the Xtreme Alps Study. Front Physiol 2022; 13:827235. [PMID: 35295581 PMCID: PMC8918982 DOI: 10.3389/fphys.2022.827235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Accepted: 01/18/2022] [Indexed: 11/13/2022] Open
Abstract
Introduction Nitrate supplementation in the form of beetroot juice (BRJ) ingestion has been shown to improve exercise tolerance during acute hypoxia, but its effect on exercise physiology remains unstudied during sustained terrestrial high altitude exposure. We hypothesized that performing exercise at high altitude would lower circulating nitrate and nitrite levels and that BRJ ingestion would reverse this phenomenon while concomitantly improving key determinants of aerobic exercise performance. Methods Twenty seven healthy volunteers (21 male) underwent a series of exercise tests at sea level (SL, London, 75 m) and again after 5-8 days at high altitude (HA, Capanna Regina Margherita or "Margherita Hut," 4,559 m). Using a double-blind protocol, participants were randomized to consume a beetroot/fruit juice beverage (three doses per day) with high levels of nitrate (∼0.18 mmol/kg/day) or a nitrate-depleted placebo (∼11.5 μmoles/kg/day) control drink, from 3 days prior to the exercise trials until completion. Submaximal constant work rate cycle tests were performed to determine exercise efficiency and a maximal incremental ramp exercise test was undertaken to measure aerobic capacity, using breath-by-breath pulmonary gas exchange measurements throughout. Concentrations of nitrate, nitrite and nitrosation products were quantified in plasma samples collected at 5 timepoints during the constant work rate tests. Linear mixed modeling was used to analyze data. Results At both SL and HA, plasma nitrate concentrations were elevated in the nitrate supplementation group compared to placebo (P < 0.001) but did not change throughout increasing exercise work rate. Delta exercise efficiency was not altered by altitude exposure (P = 0.072) or nitrate supplementation (P = 0.836). V̇O2peak decreased by 24% at high altitude (P < 0.001) and was lower in the nitrate-supplemented group at both sea level and high altitude compared to placebo (P = 0.041). Dietary nitrate supplementation did not alter other peak exercise variables or oxygen consumption at anaerobic threshold. Circulating nitrite and S-nitrosothiol levels unexpectedly rose in a few individuals right after cessation of exercise at high altitude. Conclusion Whilst regularly consumed during an 8 days expedition to terrestrial high altitude, nitrate supplementation did not alter exercise efficiency and other exercise physiological variables, except decreasing V̇O2peak. These results and those of others question the practical utility of BRJ consumption during prolonged altitude exposure.
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Affiliation(s)
- Philip J Hennis
- Centre for Altitude Space and Extreme Environment Medicine, University College London Hospital NIHR Biomedical Research Centre, Institute of Sport, Exercise and Health, London, United Kingdom.,SHAPE Research Group, School of Science and Technology, Nottingham Trent University, Nottingham, United Kingdom
| | - Andrew F Cumpstey
- Perioperative and Critical Care Theme, NIHR Southampton Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom.,Integrative Physiology and Critical Illness Group, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Alasdair F O'Doherty
- Department of Sport, Exercise and Rehabilitation, Northumbria University, Newcastle upon Tyne, United Kingdom
| | - Bernadette O Fernandez
- Integrative Physiology and Critical Illness Group, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom.,Division of Metabolic and Vascular Health, Warwick Medical School, University of Warwick, Coventry, United Kingdom
| | - Edward T Gilbert-Kawai
- Centre for Altitude Space and Extreme Environment Medicine, University College London Hospital NIHR Biomedical Research Centre, Institute of Sport, Exercise and Health, London, United Kingdom
| | - Kay Mitchell
- Perioperative and Critical Care Theme, NIHR Southampton Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom.,Integrative Physiology and Critical Illness Group, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Helen Moyses
- Perioperative and Critical Care Theme, NIHR Southampton Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom
| | - Alexandra Cobb
- Centre for Altitude Space and Extreme Environment Medicine, University College London Hospital NIHR Biomedical Research Centre, Institute of Sport, Exercise and Health, London, United Kingdom
| | - Paula Meale
- Centre for Altitude Space and Extreme Environment Medicine, University College London Hospital NIHR Biomedical Research Centre, Institute of Sport, Exercise and Health, London, United Kingdom
| | - Helmut Pöhnl
- AURAPA Würzungen GmbH, Bietigheim-Bissingen, Germany
| | - Monty G Mythen
- Centre for Altitude Space and Extreme Environment Medicine, University College London Hospital NIHR Biomedical Research Centre, Institute of Sport, Exercise and Health, London, United Kingdom
| | - Michael P W Grocott
- Perioperative and Critical Care Theme, NIHR Southampton Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom.,Integrative Physiology and Critical Illness Group, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Denny Z H Levett
- Perioperative and Critical Care Theme, NIHR Southampton Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom.,Integrative Physiology and Critical Illness Group, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Daniel S Martin
- Centre for Altitude Space and Extreme Environment Medicine, University College London Hospital NIHR Biomedical Research Centre, Institute of Sport, Exercise and Health, London, United Kingdom.,Peninsula Medical School, University of Plymouth, Plymouth, United Kingdom
| | - Martin Feelisch
- Perioperative and Critical Care Theme, NIHR Southampton Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom.,Integrative Physiology and Critical Illness Group, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom.,Division of Metabolic and Vascular Health, Warwick Medical School, University of Warwick, Coventry, United Kingdom
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12
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Sousa A, Viana JL, Milheiro J, Reis VM, Millet GP. Dietary Nitrate Supplementation Is Not Helpful for Endurance Performance at Simulated Altitude Even When Combined With Intermittent Normobaric Hypoxic Training. Front Physiol 2022; 13:839996. [PMID: 35360239 PMCID: PMC8964050 DOI: 10.3389/fphys.2022.839996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 02/16/2022] [Indexed: 11/13/2022] Open
Abstract
IntroductionTraining intensity and nutrition may influence adaptations to training performed in hypoxia and consequently performance outcomes at altitude. This study investigates if performance at simulated altitude is improved to a larger extent when high-intensity interval training is performed in normobaric hypoxia and if this is potentiated when combined with chronic dietary nitrate (NO3−) supplementation.MethodsThirty endurance-trained male participants were allocated to one of three groups: hypoxia (13% FiO2) + NO3−; hypoxia + placebo; and normoxia (20.9% FiO2) + placebo. All performed 12 cycling sessions (eight sessions of 2*6 × 1 min at severe intensity with 1 min recovery and four sessions of 4*6*10 s all-out with 20 s recovery) during a 4-week period (three sessions/week) with supplementation administered 3–2.5 h before each session. An incremental exhaustion test, a severe intensity exercise bout to exhaustion (Tlim) and a 3 min all-out test (3AOT) in hypoxia (FiO2 = 13%) with pulmonary oxygen uptake (V˙O2), V˙O2 kinetics, and changes in vastus lateralis local O2 saturation (SmO2) measured were completed by each participant before and after training.ResultsIn all tests, performance improved to the same extent in hypoxia and normoxia, except for SmO2 after Tlim (p = 0.04, d = 0.82) and 3AOT (p = 0.03, d = 1.43) which were lower in the two hypoxic groups compared with the normoxic one. Dietary NO3− supplementation did not bring any additional benefits.ConclusionPerformance at simulated altitude was not improved to a larger extent when high-intensity interval training was undertaken in normobaric hypoxic conditions, when compared with normoxic training. Additionally, dietary NO3− supplementation was ineffective in further enhancing endurance performance at simulated altitude.
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Affiliation(s)
- Ana Sousa
- Research Center in Sports Sciences, Health Sciences and Human Development (CIDESD), University of Trás-Os-Montes and Alto Douro, Vila Real, Portugal
- Research Center in Sports Sciences, Health Sciences and Human Development (CIDESD), Instituto Universitário da Maia (ISMAI), Maia, Portugal
- *Correspondence: Ana Sousa,
| | - João L. Viana
- Research Center in Sports Sciences, Health Sciences and Human Development (CIDESD), Instituto Universitário da Maia (ISMAI), Maia, Portugal
| | - Jaime Milheiro
- CMEP - Exercise Medical Center & Spa, Porto, Portugal
- Olympic Committee of Portugal, Lisbon, Portugal
| | - Vítor M. Reis
- Research Center in Sports Sciences, Health Sciences and Human Development (CIDESD), University of Trás-Os-Montes and Alto Douro, Vila Real, Portugal
| | - Grégoire P. Millet
- ISSUL, Institute of Sport Sciences and Physical Education (ISSEP), University of Lausanne, Lausanne, Switzerland
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13
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Horiuchi M, Rossetti GM, Oliver SJ. Dietary nitrate supplementation effect on dynamic cerebral autoregulation in normoxia and acute hypoxia. J Cereb Blood Flow Metab 2022; 42:486-494. [PMID: 32151227 PMCID: PMC8985441 DOI: 10.1177/0271678x20910053] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
We tested the hypothesis that increasing the nitric oxide (NO) bioavailability by dietary nitrate would recover the hypoxia-induced reduction in dynamic cerebral autoregulation (CA). Twelve healthy males (age 21 ± 2 years) completed four days of dietary supplementation with a placebo or inorganic nitrate drink (140-ml beetroot juice per day) followed by 60-min of normoxia or hypoxia (fraction of inspired oxygen [FiO2] = 13%). Duplex ultrasonography was used to perform volumetric change-based assessment of dynamic CA in the internal carotid artery (ICA). Dynamic CA was assessed by rate of regulation (RoR) of vascular conductance using the thigh-cuff method. Four days of beetroot supplementation increased circulating nitrate by 208 [171,245] μM (mean difference [95% confidence interval]) compared with placebo. Dynamic CA was lower in hypoxia than normoxia (RoR Δ-0.085 [-0.116, -0.054]). Compared with placebo, nitrate did not alter dynamic CA in normoxia (RoR Δ-0.022 [-0.060, 0.016]) or hypoxia (RoR Δ0.017 [-0.019, 0.053]). Further, nitrate did not affect ICA vessel diameter, blood velocity or flow in either normoxia or hypoxia. Increased bioavailability of NO through dietary nitrate supplementation did not recover the hypoxia-induced reduction in dynamic CA. This suggests the mechanism of hypoxia-induced reduction in dynamic CA does not relate to the availability of NO.
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Affiliation(s)
- Masahiro Horiuchi
- Division of Human Environmental Science, Mt. Fuji Research Institute, Fujiyoshida, Japan
| | - Gabriella Mk Rossetti
- Extremes Research Group, College of Human Sciences, Bangor University, Bangor, Wales
| | - Samuel J Oliver
- Extremes Research Group, College of Human Sciences, Bangor University, Bangor, Wales
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14
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Poffé C, Robberechts R, Podlogar T, Kusters M, Debevec T, Hespel P. Exogenous ketosis increases blood and muscle oxygenation but not performance during exercise in hypoxia. Am J Physiol Regul Integr Comp Physiol 2021; 321:R844-R857. [PMID: 34668436 DOI: 10.1152/ajpregu.00198.2021] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Available evidence indicates that elevated blood ketones are associated with improved hypoxic tolerance in rodents. From this perspective, we hypothesized that exogenous ketosis by oral intake of the ketone ester (R)-3-hydroxybutyl (R)-3-hydroxybutyrate (KE) may induce beneficial physiological effects during prolonged exercise in acute hypoxia. As we recently demonstrated KE to deplete blood bicarbonate, which per se may alter the physiological response to hypoxia, we evaluated the effect of KE both in the presence and absence of bicarbonate intake (BIC). Fourteen highly trained male cyclists performed a simulated cycling race (RACE) consisting of 3-h intermittent cycling (IMT180') followed by a 15-min time-trial (TT15') and an all-out sprint at 175% of lactate threshold (SPRINT). During RACE, fraction of inspired oxygen ([Formula: see text]) was gradually decreased from 18.6% to 14.5%. Before and during RACE, participants received either 1) 75 g of ketone ester (KE), 2) 300 mg/kg body mass bicarbonate (BIC), 3) KE + BIC, or 4) a control drink in addition to 60 g of carbohydrates/h in a randomized, crossover design. KE counteracted the hypoxia-induced drop in blood ([Formula: see text]) and muscle oxygenation by ∼3%. In contrast, BIC decreased [Formula: see text] by ∼2% without impacting muscle oxygenation. Performance during TT15' and SPRINT were similar between all conditions. In conclusion, KE slightly elevated the degree of blood and muscle oxygenation during prolonged exercise in moderate hypoxia without impacting exercise performance. Our data warrant to further investigate the potential of exogenous ketosis to improve muscular and cerebral oxygenation status, and exercise tolerance in extreme hypoxia.
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Affiliation(s)
- Chiel Poffé
- Exercise Physiology Research Group, Department of Movement Sciences, KU Leuven, Leuven, Belgium
| | - Ruben Robberechts
- Exercise Physiology Research Group, Department of Movement Sciences, KU Leuven, Leuven, Belgium
| | - Tim Podlogar
- Department for Automation, Biocybernetics and Robotics, Jožef Stefan Institute, Ljubljana, Slovenia.,Faculty of Health Sciences, University of Primorska, Izola, Slovenia
| | - Martijn Kusters
- Bakala Academy-Athletic Performance Center, KU Leuven, Leuven, Belgium
| | - Tadej Debevec
- Department for Automation, Biocybernetics and Robotics, Jožef Stefan Institute, Ljubljana, Slovenia.,Faculty of Sport, University of Ljubljana, Ljubljana, Slovenia
| | - Peter Hespel
- Exercise Physiology Research Group, Department of Movement Sciences, KU Leuven, Leuven, Belgium.,Bakala Academy-Athletic Performance Center, KU Leuven, Leuven, Belgium
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15
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Thurston TS, Weavil JC, Hureau TJ, Gifford JR, Georgescu VP, Wan HY, La Salle DT, Richardson RS, Amann M. On the implication of dietary nitrate supplementation for the hemodynamic and fatigue response to cycling exercise. J Appl Physiol (1985) 2021; 131:1691-1700. [PMID: 34672767 PMCID: PMC8714979 DOI: 10.1152/japplphysiol.00400.2021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 09/22/2021] [Accepted: 10/14/2021] [Indexed: 11/22/2022] Open
Abstract
This study investigated the impact of dietary nitrate supplementation on peripheral hemodynamics, the development of neuromuscular fatigue, and time to task failure during cycling exercise. Eleven recreationally active male participants (27 ± 5 yr, V̇o2max: 42 ± 2 mL/kg/min) performed two experimental trials following 3 days of either dietary nitrate-rich beetroot juice (4.1 mmol NO3-/day; DNS) or placebo (PLA) supplementation in a blinded, counterbalanced order. Exercise consisted of constant-load cycling at 50, 75, and 100 W (4 min each) and, at ∼80% of peak power output (218 ± 12 W), to task-failure. All participants returned to repeat the shorter of the two trials performed to task failure, but with the opposite supplementation regime (iso-time comparison; ISO). Mean arterial pressure (MAP), leg blood flow (QL; Doppler ultrasound), leg vascular conductance (LVC), and pulmonary gas exchange were continuously assessed during exercise. Locomotor muscle fatigue was determined by the change in pre to postexercise quadriceps twitch-torque (ΔQtw) and voluntary activation (ΔVA; electrical femoral nerve stimulation). Following DNS, plasma [nitrite] (∼670 vs. ∼180 nmol) and [nitrate] (∼775 vs. ∼11 μmol) were significantly elevated compared with PLA. Unlike PLA, DNS lowered both QL and MAP by ∼8% (P < 0.05), but did not alter LVC (P = 0.31). V̇O2 across work rates, as well as cycling time to task-failure (∼7 min) and locomotor muscle fatigue following the ISO-time comparison were not different between the two conditions (ΔQtw ∼42%, ΔVA ∼4%). Thus, despite significant hemodynamic changes, DNS did not alter the development of locomotor muscle fatigue and, ultimately, cycling time to task failure.NEW & NOTEWORTHY This study sought to characterize the impact of dietary nitrate supplementation on the hemodynamic response, locomotor muscle fatigue, and time to task failure during cycling exercise. Although nitrate supplementation lowered mean arterial pressure and exercising leg blood flow, leg vascular conductance and oxygen utilization were unaffected. Despite significant hemodynamic changes, there was no effect of dietary nitrate on neuromuscular fatigue development and, ultimately, cycling time to task failure.
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Affiliation(s)
- Taylor S Thurston
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah
| | - Joshua C Weavil
- Geriatric Research, Education, and Clinical Center, Salt Lake City, Utah
| | - Thomas J Hureau
- Department of Medicine, University of Utah, Salt Lake City, Utah
| | - Jayson R Gifford
- Department of Medicine, University of Utah, Salt Lake City, Utah
| | - Vincent P Georgescu
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah
| | - Hsuan-Yu Wan
- Department of Anesthesiology, University of Utah, Salt Lake City, Utah
| | - D Taylor La Salle
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah
| | - Russell S Richardson
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah
- Geriatric Research, Education, and Clinical Center, Salt Lake City, Utah
- Department of Medicine, University of Utah, Salt Lake City, Utah
| | - Markus Amann
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah
- Geriatric Research, Education, and Clinical Center, Salt Lake City, Utah
- Department of Medicine, University of Utah, Salt Lake City, Utah
- Department of Anesthesiology, University of Utah, Salt Lake City, Utah
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16
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Pavitt MJ, Lewis A, Buttery SC, Fernandez BO, Mikus-Lelinska M, Banya WAS, Feelisch M, Polkey MI, Hopkinson NS. Dietary nitrate supplementation to enhance exercise capacity in hypoxic COPD: EDEN-OX, a double-blind, placebo-controlled, randomised cross-over study. Thorax 2021; 77:968-975. [PMID: 34853156 DOI: 10.1136/thoraxjnl-2021-217147] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 11/04/2021] [Indexed: 11/03/2022]
Abstract
RATIONALE Dietary nitrate supplementation improves skeletal muscle oxygen utilisation and vascular endothelial function. We hypothesised that these effects might be sufficient to improve exercise performance in patients with COPD and hypoxia severe enough to require supplemental oxygen. METHODS We conducted a single-centre, double-blind, placebo-controlled, cross-over study, enrolling adults with COPD who were established users of long-term oxygen therapy. Participants performed an endurance shuttle walk test, using their prescribed oxygen, 3 hours after consuming either 140 mL of nitrate-rich beetroot juice (BRJ) (12.9 mmol nitrate) or placebo (nitrate-depleted BRJ). Treatment order was allocated (1:1) by computer-generated block randomisation. MEASUREMENTS The primary outcome was endurance shuttle walk test time. The secondary outcomes included area under the curve to isotime for fingertip oxygen saturation and heart rate parameters during the test, blood pressure, and endothelial function assessed using flow-mediated dilatation. Plasma nitrate and nitrite levels as well as FENO were also measured. MAIN RESULTS 20 participants were recruited and all completed the study. Nitrate-rich BRJ supplementation prolonged exercise endurance time in all participants as compared with placebo: median (IQR) 194.6 (147.5-411.7) s vs 159.1 (121.9-298.5) s, estimated treatment effect 62 (33-106) s (p<0.0001). Supplementation also improved endothelial function: NR-BRJ group +4.1% (-1.1% to 14.8%) vs placebo BRJ group -5.0% (-10.6% to -0.6%) (p=0.0003). CONCLUSION Acute dietary nitrate supplementation increases exercise endurance in patients with COPD who require supplemental oxygen.Trial registration number ISRCTN14888729.
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Affiliation(s)
- Matthew J Pavitt
- National Heart and Lung Institute, Imperial College London, London, UK
| | - Adam Lewis
- National Heart and Lung Institute, Imperial College London, London, UK
| | - Sara C Buttery
- National Heart and Lung Institute, Imperial College London, London, UK
| | | | | | - Winston A S Banya
- National Heart and Lung Institute, Imperial College London, London, UK
| | - Martin Feelisch
- Faculty of Medicine, Clinical and Experimental Sciences, University of Southampton, Southampton, UK.,Southampton NIHR Respiratory Biomedical Research Unit, Southampton General Hospital, Southampton, UK
| | - Michael I Polkey
- National Heart and Lung Institute, Imperial College London, London, UK.,Respiratory Medicine, Royal Brompton Hospital, London, UK
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17
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Broeder CE, Flores V, Julian B, Wojan F, Tauber R, Schubert L, Salacinski A, Ivy JL. Nitric oxide enhancement supplement containing beet nitrite and nitrate benefits high intensity cycle interval training. Curr Res Physiol 2021; 4:183-191. [PMID: 34746837 PMCID: PMC8562140 DOI: 10.1016/j.crphys.2021.07.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 07/27/2021] [Accepted: 07/30/2021] [Indexed: 11/25/2022] Open
Abstract
This study investigated the effects of a beet nitric oxide enhancing (NOE) supplement comprised of nitrite and nitrate on cycling performance indices in trained cyclists. METHODS Subjects completed a lactate threshold test and a high-intensity interval (HIIT) protocol at 50% above functional threshold power with or without oral NOE supplement. RESULTS NOE supplementation enhanced lactate threshold by 7.2% (Placebo = 191.6 ± 37.3 W, NOE = 205.3 ± 39.9; p = 0.01; Effect Size (ES) = 0.40). During the HIIT protocol, NOE supplementation improved time to exhaustion 18% (Placebo = 1251 ± 562s, NOE = 1474 ± 504s; p = 0.02; ES = 0.42) and total energy expended 22.3% (Placebo = 251 ± 48.6 kJ, NOE = 306.6 ± 55.2 kJ; p = 0.01; ES = 1.079). NOE supplementation increased the intervals completed (Placebo = 7.00 ± 2.5, NOE = 8.14 ± 2.4; p = 0.03; ES = 0.42) and distance cycled (Placebo = 10.9 ± 4.0 km, NOE = 13.5 ± 3.9 km; p = 0.01; ES = 0.65). Also, target power was achieved at a higher cadence during the HIIT work and rest periods (p = 0.02), which enhanced muscle oxygen saturation (SmO2) recovery. Time-to-fatigue was negatively correlated with the degree of SmO2, desaturation during the HIIT work interval segment (r = -0.67; p 0.008), while both SmO2 desaturation and the SmO2 starting work segment saturation level correlated with a cyclist's kJ expended (SmO2 desaturation: r = -0.51, p = 0.06; SmO2 starting saturation: r = 0.59, p = 0.03). CONCLUSION NOE supplementation containing beet nitrite and nitrate enhanced submaximal (lactate threshold) and HIIT maximal effort work. The NOE supplementation resulted in a cyclist riding at higher cadence rates with lower absolute torque values at the same power during both the work and rest periods, which in-turn delayed over-all fatigue and improved total work output.
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Affiliation(s)
- Craig E Broeder
- Exercising Nutritionally, LLC, United States.,Northern Illinois University, United States
| | | | - Bill Julian
- Exercising Nutritionally, LLC, United States
| | - Frank Wojan
- Exercising Nutritionally, LLC, United States.,University of Texas at Austin, United States
| | | | | | - Amanda Salacinski
- Exercising Nutritionally, LLC, United States.,Westfield State University, United States
| | - John L Ivy
- University of Texas at Austin, United States
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18
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Macuh M, Knap B. Effects of Nitrate Supplementation on Exercise Performance in Humans: A Narrative Review. Nutrients 2021; 13:3183. [PMID: 34579061 PMCID: PMC8465461 DOI: 10.3390/nu13093183] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Revised: 09/04/2021] [Accepted: 09/10/2021] [Indexed: 12/20/2022] Open
Abstract
Nitrates have become increasingly popular for their potential role as an ergogenic aid. The purpose of this article was to review the current scientific evidence of nitrate supplementation on human performance. The current recommendation of nitrate supplementation is discussed, as well as possible health complications associated with nitrate intake for athletes, and dietary strategies of covering nitrate needs through sufficient intake of nitrate-rich foods alone are presented. Pubmed, Scopus, and Web of Science were searched for articles on the effects of nitrate supplementation in humans. Nitrates are an effective ergogenic aid when taken acutely or chronically in the range of ~5-16.8 mmol (~300-1041 mg) 2-3 h before exercise and primarily in the case of exercise duration of ~10-17 min in less trained individuals (VO2max < 65 mL/kg/min). Nitrate needs are most likely meet by ingesting approximately 250-500 g of leafy and root vegetables per day; however, dietary supplements might represent a more convenient and accurate way of covering an athlete's nitrate needs. Athletes should refrain from mouthwash usage when nitrate supplementation benefits are desired. Future research should focus on the potential beneficial effects of nitrate supplementation on brain function, possible negative impacts of chronic nitrate supplementation through different nitrate sources, and the effectiveness of nitrate supplementation on strength and high-intensity intermittent exercise.
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Affiliation(s)
- Matjaž Macuh
- Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana; Jamnikarjeva 10, 1000 Ljubljana, Slovenia
| | - Bojan Knap
- Department of Nephrology, University Medical Centre Ljubljana, Zaloška 7, 1000 Ljubljana, Slovenia;
- Faculty of Medicine, University of Ljubljana, Korytkova ulica 2, 1000 Ljubljana, Slovenia
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19
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Alsulayyim AS, Alasmari AM, Alghamdi SM, Polkey MI, Hopkinson NS. Impact of dietary nitrate supplementation on exercise capacity and cardiovascular parameters in chronic respiratory disease: a systematic review and meta-analysis. BMJ Open Respir Res 2021; 8:8/1/e000948. [PMID: 34489239 PMCID: PMC8422488 DOI: 10.1136/bmjresp-2021-000948] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 08/20/2021] [Indexed: 12/15/2022] Open
Abstract
Background Dietary nitrate supplementation, usually in the form of beetroot juice, may improve exercise performance and endothelial function. We undertook a systematic review and meta-analysis to establish whether this approach has beneficial effects in people with respiratory disease. Methods A systematic search of records up to March 2021 was performed on PubMed, CINAHL, MEDLINE (Ovid), Cochrane and Embase to retrieve clinical trials that evaluated the efficacy of dietary nitrate supplementation on cardiovascular parameters and exercise capacity in chronic respiratory conditions. Two authors independently screened titles, abstracts and full texts of potential studies and performed the data extraction. Results After full-text review of 67 papers, eleven (two randomised controlled trials and nine crossover trials) involving 282 participants met the inclusion criteria. Three were single dose; seven short term; and one, the largest (n=122), done in the context of pulmonary rehabilitation. Pooled analysis showed that dietary nitrate supplementation reduced systolic blood pressure (BP), diastolic BP and mean arterial pressure (mean difference (95% CI), −3.39 mm Hg (−6.79 to 0.01); p=0.05 and –2.20 mm Hg (−4.36 to −0.03); p=0.05 and −4.40 mm Hg (−7.49 to −1.30); p=0.005, respectively). It was associated with increased walk distance in the context of pulmonary rehabilitation (standardised mean difference (95% CI), 0.47 (0.11 to 0.83), p=0.01), but no effect was identified in short-term studies (0.08 (−0.32 to 0.49). Conclusion Dietary nitrate supplementation may have a beneficial effect on BP and augment the effect of pulmonary rehabilitation on exercise capacity. Short-term studies do not suggest a consistent benefit on exercise capacity. PROSPERO registration number CRD42019130123.
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Affiliation(s)
- Abdullah S Alsulayyim
- National Heart and Lung Institute, Imperial College London, London, UK.,Faculty of Applied Medical Sciences, Respiratory Therapy Department, Jazan University, Jazan, Saudi Arabia
| | - Ali M Alasmari
- National Heart and Lung Institute, Imperial College London, London, UK.,Faculty of Medical Rehabilitation Sciences, Taibah University, Madinah, Saudi Arabia
| | - Saeed M Alghamdi
- National Heart and Lung Institute, Imperial College London, London, UK.,Clinical Technology Department, Umm Al-Qura University, College of Applied Medical Science, Makkah, Saudi Arabia
| | - Michael I Polkey
- National Heart and Lung Institute, Imperial College London, London, UK
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Sousa A, Viana JL, Milheiro J, Reis VM, Millet GP. Effect of hypoxia and nitrate supplementation on different high-intensity interval-training sessions. Eur J Appl Physiol 2021; 121:2585-2594. [PMID: 34097130 DOI: 10.1007/s00421-021-04726-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 05/20/2021] [Indexed: 11/28/2022]
Abstract
PURPOSE To test the hypothesis that interval-training (IHT) would be impaired by hypoxia to a larger extent than repeated-sprint training (RSH) and that dietary nitrate (NO3-) would mitigate the detrimental effect of hypoxia to a larger extent during IHT than RSH. METHODS Thirty endurance-trained male participants performed IHT (6 × 1 min at 90%∆ with 1 min active recovery) and RSH (2 sets of 6 × 10 s "all-out" efforts with 20 s active recovery) on a cycle ergometer, allocated in one of three groups: normobaric hypoxia (~ 13% FiO2) + NO3- - HNO, n = 10; normobaric hypoxia + placebo - HPL, n = 10; normoxia (20.9% FiO2) + placebo - CON, n = 10. Submaximal oxygen uptake ([Formula: see text]O2), time spent above 90% of maximal [Formula: see text]O2 (≥ 90 [Formula: see text]O2max) and heart rate (≥ 90 HRmax) were compared between IHT and RSH sessions and groups. Additionally, mean power output (MPO), decrement score and % of power associated with [Formula: see text]O2max (%p[Formula: see text]O2max) in RSH sessions were analyzed. RESULTS [Formula: see text]O2 at sub-maximal intensities did not differ between training protocols and groups (~ 27 ml kg-1 min-1). ≥ 90 HRmax was significantly higher in IHT compared to RSH session (39 ± 8 vs. 30 ± 8%, p = 0.03) but only in HNO group. MPO (range 360-490 W) and decrement score (10-13%) were similar between groups although %p[Formula: see text]O2max was significantly higher (p = 0.04) in CON (166 ± 16 W) compared with both HPL (147 ± 15 W) and HNO (144 ± 10 W) groups. CONCLUSION IHT responses were neither more impaired by hypoxia than RSH ones. Moreover, dietary NO3- supplementation impacted equally IHT and RSH training responses' differences between hypoxia and normoxia.
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Affiliation(s)
- A Sousa
- Research Center in Sports Sciences, Health Sciences and Human Development, CIDESD, University of Trás-Os-Montes and Alto Douro, Vila Real, Portugal. .,Research Center in Sports Sciences, Health Sciences and Human Development, CIDESD, University Institute of Maia, ISMAI, Maia, Portugal.
| | - J L Viana
- Research Center in Sports Sciences, Health Sciences and Human Development, CIDESD, University Institute of Maia, ISMAI, Maia, Portugal
| | - J Milheiro
- CMEP Exercise Medical Center & SPA, Porto, Portugal.,Olympic Committee of Portugal, Lisbon, Portugal
| | - V M Reis
- Research Center in Sports Sciences, Health Sciences and Human Development, CIDESD, University of Trás-Os-Montes and Alto Douro, Vila Real, Portugal
| | - G P Millet
- ISSUL, Institute of Sport Sciences and Physical Education (ISSEP), University of Lausanne, Lausanne, Switzerland
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Marshall AR, Rimmer JE, Shah N, Bye K, Kipps C, Woods DR, O'Hara J, Boos CJ, Barlow M. Marching to the Beet: The effect of dietary nitrate supplementation on high altitude exercise performance and adaptation during a military trekking expedition. Nitric Oxide 2021; 113-114:70-77. [PMID: 34051342 DOI: 10.1016/j.niox.2021.05.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 03/19/2021] [Accepted: 05/23/2021] [Indexed: 10/21/2022]
Abstract
PURPOSE The aim was to investigate the effect of dietary nitrate supplementation (in the form of beetroot juice, BRJ) for 20 days on salivary nitrite (a potential precursor of bioactive nitric oxide), exercise performance and high altitude (HA) acclimatisation in field conditions (hypobaric hypoxia). METHODS This was a single-blinded randomised control study of 22 healthy adult participants (12 men, 10 women, mean age 28 ± 12 years) across a HA military expedition. Participants were randomised pre-ascent to receive two 70 ml dose per day of either BRJ (~12.5 mmol nitrate per day; n = 11) or non-nitrate calorie matched control (n = 11). Participants ingested supplement doses daily, beginning 3 days prior to departure and continued until the highest sleeping altitude (4800 m) reached on day 17 of the expedition. Data were collected at baseline (44 m altitude), at 2350 m (day 9), 3400 m (day 12) and 4800 m (day 17). RESULTS BRJ enhanced the salivary levels of nitrite (p = 0.007). There was a significant decrease in peripheral oxygen saturation and there were increases in heart rate, diastolic blood pressure, and rating of perceived exertion with increasing altitude (p=<0.001). Harvard Step Test fitness scores significantly declined at 4800 m in the control group (p = 0.003) compared with baseline. In contrast, there was no decline in fitness scores at 4800 m compared with baseline (p = 0.26) in the BRJ group. Heart rate recovery speed following exercise at 4800 m was significantly prolonged in the control group (p=<0.01) but was unchanged in the BRJ group (p = 0.61). BRJ did not affect the burden of HA illness (p = 1.00). CONCLUSIONS BRJ increases salivary nitrite levels and ameliorates the decline in fitness at altitude but does not affect the occurrence of HA illness.
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Affiliation(s)
- Anna R Marshall
- Department of Surgical and Interventional Sciences, Institute of Sport, Exercise & Health, UCL, London, WC1E 6B, UK.
| | | | - Nishma Shah
- Department of Surgical and Interventional Sciences, Institute of Sport, Exercise & Health, UCL, London, WC1E 6B, UK
| | - Kyo Bye
- Defence Medical Services, Lichfield, WS14 9PY, UK
| | - Courtney Kipps
- Department of Surgical and Interventional Sciences, Institute of Sport, Exercise & Health, UCL, London, WC1E 6B, UK
| | - David R Woods
- Defence Medical Services, Lichfield, WS14 9PY, UK; Carneige School of Sport, Leeds Beckett University, Leeds, LS16 5LF, UK; Northumbria and Newcastle NHS Trusts, Wansbeck General and Royal Victoria Infirmary, Newcastle, NE66 2NS, UK
| | - John O'Hara
- Carneige School of Sport, Leeds Beckett University, Leeds, LS16 5LF, UK
| | - Christopher J Boos
- Carneige School of Sport, Leeds Beckett University, Leeds, LS16 5LF, UK; Department of Cardiology, Poole Hospital NHS Foundation Trust, Poole, BH15 2JB, UK; Department of Postgraduate Medical Education, Bournemouth University, Bournemouth, BH1 3LT, UK
| | - Matthew Barlow
- Carneige School of Sport, Leeds Beckett University, Leeds, LS16 5LF, UK
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Rokkedal-Lausch T, Franch J, Poulsen MK, Thomsen LP, Weitzberg E, Kamavuako EN, Karbing DS, Larsen RG. Multiple-day high-dose beetroot juice supplementation does not improve pulmonary or muscle deoxygenation kinetics of well-trained cyclists in normoxia and hypoxia. Nitric Oxide 2021; 111-112:37-44. [PMID: 33831566 DOI: 10.1016/j.niox.2021.03.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 03/24/2021] [Accepted: 03/31/2021] [Indexed: 10/21/2022]
Abstract
Dietary nitrate (NO3-) supplementation via beetroot juice (BR) has been reported to lower oxygen cost (i.e., increased exercise efficiency) and speed up oxygen uptake (VO2) kinetics in untrained and moderately trained individuals, particularly during conditions of low oxygen availability (i.e., hypoxia). However, the effects of multiple-day, high dose (12.4 mmol NO3- per day) BR supplementation on exercise efficiency and VO2 kinetics during normoxia and hypoxia in well-trained individuals are not resolved. In a double-blinded, randomized crossover study, 12 well-trained cyclists (66.4 ± 5.3 ml min-1∙kg-1) completed three transitions from rest to moderate-intensity (~70% of gas exchange threshold) cycling in hypoxia and normoxia with supplementation of BR or nitrate-depleted BR as placebo. Continuous measures of VO2 and muscle (vastus lateralis) deoxygenation (ΔHHb, using near-infrared spectroscopy) were acquired during all transitions. Kinetics of VO2 and deoxygenation (ΔHHb) were modeled using mono-exponential functions. Our results showed that BR supplementation did not alter the primary time constant for VO2 or ΔHHb during the transition from rest to moderate-intensity cycling. While BR supplementation lowered the amplitude of the VO2 response (2.1%, p = 0.038), BR did not alter steady state VO2 derived from the fit (p = 0.258), raw VO2 data (p = 0.231), moderate intensity exercise efficiency (p = 0.333) nor steady state ΔHHb (p = 0.224). Altogether, these results demonstrate that multiple-day, high-dose BR supplementation does not alter exercise efficiency or oxygen uptake kinetics during normoxia and hypoxia in well-trained athletes.
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Affiliation(s)
- Torben Rokkedal-Lausch
- Sport Sciences - Performance and Technology, Department of Health Science and Technology, Aalborg University, DK-9220, Aalborg, Denmark.
| | - Jesper Franch
- Sport Sciences - Performance and Technology, Department of Health Science and Technology, Aalborg University, DK-9220, Aalborg, Denmark
| | - Mathias K Poulsen
- Respiratory and Critical Care Group, Department of Health Science and Technology, Aalborg University, DK-9220, Aalborg, Denmark
| | - Lars P Thomsen
- Respiratory and Critical Care Group, Department of Health Science and Technology, Aalborg University, DK-9220, Aalborg, Denmark
| | - Eddie Weitzberg
- Department of Physiology and Pharmacology, Karolinska Institutet, 171 77, Stockholm, Sweden
| | - Ernest N Kamavuako
- Center for Robotics Research, Department of Engineering, King's College London, London, United Kingdom
| | - Dan S Karbing
- Respiratory and Critical Care Group, Department of Health Science and Technology, Aalborg University, DK-9220, Aalborg, Denmark
| | - Ryan G Larsen
- Sport Sciences - Performance and Technology, Department of Health Science and Technology, Aalborg University, DK-9220, Aalborg, Denmark
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Senefeld JW, Wiggins CC, Regimbal RJ, Dominelli PB, Baker SE, Joyner MJ. Ergogenic Effect of Nitrate Supplementation: A Systematic Review and Meta-analysis. Med Sci Sports Exerc 2021; 52:2250-2261. [PMID: 32936597 PMCID: PMC7494956 DOI: 10.1249/mss.0000000000002363] [Citation(s) in RCA: 68] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Supplemental digital content is available in the text. Although over 100 studies and reviews have examined the ergogenic effects of dietary nitrate (NO3−) supplementation in young, healthy men and women, it is unclear if participant and environmental factors modulate the well-described ergogenic effects—particularly relevant factors include biological sex, aerobic fitness, and fraction of inspired oxygen (FiO2) during exercise. To address this limitation, the literature was systematically reviewed for randomized, crossover, placebo-controlled studies reporting exercise performance outcome metrics with NO3− supplementation in young, healthy adults. Of the 2033 articles identified, 80 were eligible for inclusion in the meta-analysis. Random-effects meta-analysis demonstrated that exercise performance improved with NO3− supplementation compared with placebo (d = 0.174; 95% confidence interval (CI), 0.120–0.229; P < 0.001). Subgroup analyses conducted on biological sex, aerobic fitness, and FiO2 demonstrated that the ergogenic effect of NO3− supplementation was as follows: 1) not observed in studies with only women (n = 6; d = 0.116; 95% CI, −0.126 to 0.358; P = 0.347), 2) not observed in well-trained endurance athletes (≥65 mL·kg−1·min−1; n = 26; d = 0.021; 95% CI, −0.103 to 0.144; P = 0.745), and 3) not modulated by FiO2 (hypoxia vs normoxia). Together, the meta-analyses demonstrated a clear ergogenic effect of NO3− supplementation in recreationally active, young, healthy men across different exercise paradigms and NO3− supplementation parameters; however, the effect size of NO3− supplementation was objectively small (d = 0.174). NO3− supplementation has more limited utility as an ergogenic aid in participants with excellent aerobic fitness that have optimized other training parameters. Mechanistic research and studies incorporating a wide variety of subjects (e.g., women) are needed to advance the study of NO3− supplementation; however, additional descriptive studies of young, healthy men may have limited utility.
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Affiliation(s)
- Jonathon W Senefeld
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, MN
| | - Chad C Wiggins
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, MN
| | - Riley J Regimbal
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, MN
| | | | - Sarah E Baker
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, MN
| | - Michael J Joyner
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, MN
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Alshafie S, El-Helw GO, Fayoud AM, Elrashedy AA, Gbreel MI, Alfayoumi SS, Mohamed IM, Abdelwadoud GT, Isa AS, Ragab KM, Nourelden AZ. Efficacy of dietary nitrate-rich beetroot juice supplementation in patients with chronic obstructive pulmonary disease (COPD): A systematic review and meta-analysis. Clin Nutr ESPEN 2021; 42:32-40. [PMID: 33745600 DOI: 10.1016/j.clnesp.2021.01.035] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 01/23/2021] [Accepted: 01/26/2021] [Indexed: 10/22/2022]
Abstract
BACKGROUND Chronic Obstructive Pulmonary Disease (COPD) is a chronic inflammatory lung disease causing airflow obstruction from the lungs reducing exercise tolerance. It is one of the leading causes of respiratory dysfunction worldwide. Nitric Oxide (NO) may have a significant role in this inflammatory reaction to improve exercise capacity. AIM To evaluate the effect of dietary nitrate ingestion for COPD patients. METHODS We searched Scopus, PubMed, Cochrane, and Web of Science databases till August 2020 and updated the search in December 2020 using relevant keywords. All search results were screened for eligibility. We extracted the data from the included articles and pooled them as mean difference (MD) with a 95% confidence interval (CI), using Review Manager software (ver. 5.4). RESULTS A pooled analysis from eight included trials showed no significant difference between dietary nitrate-rich beetroot juice and placebo in systolic blood pressure, diastolic blood pressure, heart rate, 6-min walk test, cycling ergometry endurance time, and maximum rate of oxygen consumption (VO2). On the other hand, nitrate-rich beetroot juice significantly increased the Borg Rating of Perceived Exertion (RPE) scale more than the placebo (MD = -0.77; 95% CI [0.18, 1.37], P = 0.01). CONCLUSION There is no significant effect of nitrate-rich beetroot juice on cardiovascular events as systolic, diastolic blood pressure, and heart rate, or exercise performance as 6-min walk test, and cycling ergometry endurance time, or maximum rate of oxygen consumption (VO2). On the other hand, nitrate-rich beetroot juice improves the Borg Rating of Perceived Exertion (RPE) scale reflecting an increased exercise and physical activity level.
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Affiliation(s)
- Somia Alshafie
- Faculty of Medicine, Suez-canal University, Egypt; International Medical Students' Research Association IMedRA, Egypt
| | - Ghidaa Osama El-Helw
- Faculty of Medicine, Beni Suef University, Egypt; International Medical Students' Research Association IMedRA, Egypt
| | - Aya M Fayoud
- Faculty of Pharmacy, Kafr El-Shaikh University, Egypt; International Medical Students' Research Association IMedRA, Egypt
| | - Asmaa Ahmed Elrashedy
- Faculty of Medicine, Kafr El-Shaikh University, Egypt; International Medical Students' Research Association IMedRA, Egypt
| | - Mohamed Ibrahim Gbreel
- Faculty of Medicine, 6-October University, Egypt; International Medical Students' Research Association IMedRA, Egypt
| | - Saba Saleh Alfayoumi
- Faculty of Medicine, University of Jordan, Jordan; International Medical Students' Research Association IMedRA, Egypt
| | - Islam Mayhoub Mohamed
- Faculty of Pharmacy, Beni Suef University, Egypt; International Medical Students' Research Association IMedRA, Egypt
| | - Gehad Taha Abdelwadoud
- Faculty of Medicine, Fayoum University, Egypt; International Medical Students' Research Association IMedRA, Egypt
| | - Alaa Saad Isa
- Faculty of Medicine, Al-Azhar University, Damietta, Egypt; International Medical Students' Research Association IMedRA, Egypt
| | - Khaled Mohamed Ragab
- Faculty of Medicine, Minia University, Egypt; International Medical Students' Research Association IMedRA, Egypt
| | - Anas Zakarya Nourelden
- Faculty of Medicine, Al-Azhar University, Cairo, Egypt; International Medical Students' Research Association IMedRA, Egypt.
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25
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Influence of Sex and Acute Beetroot Juice Supplementation on 2 KM Running Performance. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11030977] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Purpose: To assess the effect of acute nitrate-rich (BJ) and nitrate-depleted (PL) beetroot juice ingestion on 2 km running performance in amateur runners, and to what extent the ergogenic effect of BJ supplementation would be influenced by the sex of the participants; Methods: Twenty-four amateur long-distance runners (14 males and 10 females) performed a 2 km time trial (TT) on an outdoor athletics track 2.5 h after ingesting either 140 mL of BJ (~12.8 mmol NO3−) or PL. After the tests, blood [lactate] and ratings of perceived exertion (RPE) related to the leg muscles (RPEmuscular), cardiovascular system (RPEcardio) and general overall RPE (RPEgeneral) were assessed; Results: Compared to PL, BJ supplementation improved 2 km TT performance in both males (p < 0.05) with no supplement × sex interaction effect (p > 0.05). This improvement in 2 km running performance was a function of improved performance in the second 1 km split time in both males and females (p < 0.05). Supplementation with BJ did not alter post-exercise blood [lactate] (p > 0.05) but lowered RPEgeneral (p < 0.05); Conclusions: acute BJ supplementation improves 2 km running performance in amateur runners by enhancing performance over the second half of the TT and lowering RPEgeneral by a comparable magnitude in males and females.
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Influence of Dietary Nitrate Supplementation on High-Intensity Intermittent Running Performance at Different Doses of Normobaric Hypoxia in Endurance-Trained Males. Int J Sport Nutr Exerc Metab 2020; 31:1-8. [PMID: 33260146 DOI: 10.1123/ijsnem.2020-0198] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 09/27/2020] [Accepted: 09/28/2020] [Indexed: 11/18/2022]
Abstract
This study investigated whether supplementation with nitrate-rich beetroot juice (BR) can improve high-intensity intermittent running performance in trained males in normoxia and different doses of normobaric hypoxia. Eight endurance-trained males (V˙O2peak, 62 ± 6 ml·kg-1·min-1) completed repeated 90 s intervals at 110% of peak treadmill velocity, from an initial step incremental test, interspersed by 60 s of passive recovery until exhaustion (Tlim). Participants completed the first three experimental trials during days 3, 5, and 7 of BR or nitrate-depleted beetroot juice (PLA) supplementation and completed the remaining experimental visits on the alternative supplement following at least 7 days of washout. The fraction of inspired oxygen during visits 1-3 was either 0.209, 0.182, or 0.157, equivalent to an altitude of 0, 1,200, and 2,400 m, respectively, and this order was replicated on visits 4-6. Arterial oxygen saturation declined dose dependently as fraction of inspired oxygen was lowered (p < .05). Plasma nitrite concentration was higher pre- and postexercise after BR compared with PLA supplementation (p < .05). There was no difference in Tlim between PLA and BR at 0 m (445 [324, 508] and 410 [368, 548] s); 1,200 m (341 [270, 390] and 332 [314, 356] s); or 2,400 m (233 [177, 373] and 251 [221, 323] s) (median and [interquartile range]; p > .05). The findings from this study suggest that short-term BR supplementation does not improve high-intensity intermittent running performance in endurance-trained males in normoxia or at doses of normobaric hypoxia that correspond to altitudes at which athletes typically train while on altitude training camps.
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The Possible Importance of Glutamine Supplementation to Mood and Cognition in Hypoxia from High Altitude. Nutrients 2020; 12:nu12123627. [PMID: 33255790 PMCID: PMC7760805 DOI: 10.3390/nu12123627] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Revised: 11/09/2020] [Accepted: 11/13/2020] [Indexed: 11/16/2022] Open
Abstract
Hypoxia induced by low O2 pressure is responsible for several physiological and behavioral alterations. Changes in physiological systems are frequent, including inflammation and psychobiological declines such as mood and cognition worsening, resulting in increased reaction time, difficulty solving problems, reduced memory and concentration. The paper discusses the possible relationship between glutamine supplementation and worsening cognition mediated by inflammation induced by high altitude hypoxia. The paper is a narrative literature review conducted to verify the effects of glutamine supplementation on psychobiological aspects. We searched MEDLINE/PubMed and Web of Science databases and gray literature by Google Scholar for English articles. Mechanistic pathways mediated by glutamine suggest potential positive effects of its supplementation on mood and cognition, mainly its potential effect on inflammation. However, clinical studies are scarce, making any conclusions impossible. Although glutamine plays an important role and seems to mitigate inflammation, clinical studies should test this hypothesis, which will contribute to a better mood and cognition state for several people who suffer from problems mediated by hypoxia.
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Shaw K, Singh J, Sirant L, Neary JP, Chilibeck PD. Effect of Dark Chocolate Supplementation on Tissue Oxygenation, Metabolism, and Performance in Trained Cyclists at Altitude. Int J Sport Nutr Exerc Metab 2020; 30:420-426. [PMID: 32916656 DOI: 10.1123/ijsnem.2020-0051] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 07/19/2020] [Accepted: 08/03/2020] [Indexed: 11/18/2022]
Abstract
Dark chocolate (DC) is high in flavonoids and has been shown to increase nitric oxide in the blood. Increased nitric oxide has the potential to improve delivery of oxygen to muscle, especially in hypoxic conditions, such as altitude. Our aim was to assess the impact of DC supplementation on cycling performance at altitude. Twelve healthy, trained cyclists (n = 2 females, n = 10 males; age = 35 [12] years; height = 177 [7] cm; mass = 75.2 [11.0] kg; VO2max = 55 [6] ml·kg-1·min-1) were randomized to supplement with 60 g of DC or placebo twice per day for 14 days in a double-blind crossover study. After the 2 weeks of supplementation, the participants attended a laboratory session in which they consumed 120 g of DC or placebo and then cycled for 90 min at 50% peak power output, followed immediately by a 10-km time trial (TT) at simulated altitude (15% O2). The plasma concentration of blood glucose and lactate were measured before and at 15, 30, 60, and 90 min during the steady-state exercise and post TT, while muscular and prefrontal cortex oxygenation was measured continuously throughout exercise using near-infrared spectroscopy. DC resulted in a higher concentration of blood glucose (5.5 [0.5] vs. 5.3 [0.9] mmol/L) throughout the trial and lower blood lactate concentration following the TT (7.7 [1.92] vs. 10.0 [4.6] mmol/L) compared with the placebo. DC had no effect on the TT performance (19.04 [2.16] vs. 19.21 ± 1.96 min) or oxygenation status in either the prefrontal cortex or muscle. The authors conclude that, although it provided some metabolic benefit, DC is not effective as an ergogenic aid during TT cycling at simulated altitude.
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LE Roux-Mallouf T, Vallejo A, Pelen F, Halimaoui I, Doutreleau S, Verges S. Synergetic Effect of NO Precursor Supplementation and Exercise Training. Med Sci Sports Exerc 2020; 52:2437-2447. [PMID: 33064413 DOI: 10.1249/mss.0000000000002387] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
INTRODUCTION Nitric oxide (NO) precursor supplementation has been shown to increase NO bioavailability and can potentially improve vascular function and exercise performance. It remains unclear whether the combination of NO precursor supplementation and exercise training has synergic effects on exercise performance. This study aims to assess the effect of chronic nitrate and citrulline intake on exercise training adaptations in healthy young individuals. METHODS In this randomized, double-bind trial, 24 healthy young (12 females) subjects performed vascular function assessment (blood pressure, pulse wave velocity, postischemia vasodilation, and cerebrovascular reactivity) and both local (submaximal isometric unilateral knee extension) and whole-body (incremental cycling) exercise tests to exhaustion before and after a 2-month exercise training program and daily intake of a placebo or a nitrate-rich salad and citrulline (N + C, 520 mg nitrate and 6 g citrulline) drink. Prefrontal cortex and quadriceps oxygenation was monitored continuously during exercise by near-infrared spectroscopy. RESULTS N + C supplementation had no effect on vascular function and muscle and cerebral oxygenation during both local and whole-body exercise. N + C supplementation induced a significantly larger increase in maximal knee extensor strength (+5.1 ± 3.5 vs +0.2 ± 5.5 kg, P = 0.008) as well as a trend toward a larger increase in knee extensor endurance (+35.2 ± 26.1 vs +24.0 ± 10.4 contractions, P = 0.092) than placebo, but no effect on exercise training-induced maximal aerobic performance improvement. CONCLUSION These results suggest that chronic nitrate and citrulline supplementation enhances the effect of exercise training on quadriceps muscle function in healthy active young individuals, but this does not translate into improved maximal aerobic performances.
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Affiliation(s)
| | - Angela Vallejo
- HP2 Laboratory INSERM U1042, Faculty of Medicine, Université Grenoble Alpes, Grenoble, FRANCE
| | - Felix Pelen
- HP2 Laboratory INSERM U1042, Faculty of Medicine, Université Grenoble Alpes, Grenoble, FRANCE
| | - Idir Halimaoui
- HP2 Laboratory INSERM U1042, Faculty of Medicine, Université Grenoble Alpes, Grenoble, FRANCE
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Effects of Dietary Nitrates on Time Trial Performance in Athletes with Different Training Status: Systematic Review. Nutrients 2020; 12:nu12092734. [PMID: 32911636 PMCID: PMC7551808 DOI: 10.3390/nu12092734] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 09/04/2020] [Indexed: 12/14/2022] Open
Abstract
Much research has been done in sports nutrition in recent years as the demand for performance-enhancing substances increases. Higher intake of nitrates from the diet can increase the bioavailability of nitric oxide (NO) via the nitrate-nitrite-NO pathway. Nevertheless, the increased availability of NO does not always lead to improved performance in some individuals. This review aims to evaluate the relationship between the athlete's training status and the change in time trial performance after increased dietary nitrate intake. Articles indexed by Scopus and PubMed published from 2015 to 2019 were reviewed. Thirteen articles met the eligibility criteria: clinical trial studies on healthy participants with different training status (according to VO2max), conducting time trial tests after dietary nitrate supplementation. The PRISMA guidelines were followed to process the review. We found a statistically significant relationship between VO2max and ergogenicity in time trial performance using one-way ANOVA (p = 0.001) in less-trained athletes (VO2 < 55 mL/kg/min). A strong positive correlation was observed in experimental situations using a chronic supplementation protocol but not in acute protocol situations. In the context of our results and recent histological observations of muscle fibres, there might be a fibre-type specific role in nitric oxide production and, therefore, supplement of ergogenicity.
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Liubertas T, Kairaitis R, Stasiule L, Capkauskiene S, Stasiulis A, Viskelis P, Viškelis J, Urbonaviciene D. The influence of amaranth (Amaranthus hypochondriacus) dietary nitrates on the aerobic capacity of physically active young persons. J Int Soc Sports Nutr 2020; 17:37. [PMID: 32660566 PMCID: PMC7359009 DOI: 10.1186/s12970-020-00366-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 06/30/2020] [Indexed: 11/10/2022] Open
Abstract
Background Recent evidence indicates that elevating plasma nitrites through dietary nitrates (NO3−) supplementation is associated with enhanced muscle efficiency, fatigue resistance and performance. Beetroot (in various forms) is the dominant source of dietary NO3− primarily due to its vast availability and the simple form of preparation suitable for final consumption. After a few years of research and experimentation, our scientific team identified alternative source rich with dietary NO3− as possible nitric oxide precursor, amaranth (Amaranthus hypochondriacus) with a standardized concentration 9–11% of NO3−. This study aimed to evaluate the effect of single-dose (±400 mg of dietary NO3−) and long-term (6 days) supplementation of amaranth concentrate derived dietary NO3− on aerobic capacity in physically active young people. Methods We conducted a randomized, double-blind, placebo-controlled human study. Thirteen healthy and physically active young male participants were randomized into experimental and placebo groups. The aerobic capacity was tested during increasing cycling exercise (ICE) with pulmonary gas exchange recording and analysis. Results The peak power of the ICE, the maximum oxygen consumption and the first ventilatory threshold were significantly increased after long-term consumption of dietary amaranth (from 4.44 ± 0.50 to 4.55 ± 0.43 W/kg; from 37.7 ± 2.7 to 41.2 ± 5.4 mL/kg/min and from 178.6 ± 30.3 to 188.6 ± 35.2 W, p < 0.05; respectively) in experimental group. Conclusions Long-term (6 days) use of dietary NO3− from amaranth may improve the aerobic capacity during ICE in young physically active male persons. It can be recommended as the nutritional supplement during last week of preparation for competition in endurance events.
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Affiliation(s)
- Tomas Liubertas
- Department of Coaching Science, Lithuanian Sports University, 44221, Kaunas, Lithuania.
| | - Ramutis Kairaitis
- Department of Coaching Science, Lithuanian Sports University, 44221, Kaunas, Lithuania
| | - Loreta Stasiule
- Department of Applied Biology and Rehabilitation, Lithuanian Sports University, 44221, Kaunas, Lithuania
| | - Sandrija Capkauskiene
- Department of Applied Biology and Rehabilitation, Lithuanian Sports University, 44221, Kaunas, Lithuania
| | - Arvydas Stasiulis
- Department of Applied Biology and Rehabilitation, Lithuanian Sports University, 44221, Kaunas, Lithuania
| | - Pranas Viskelis
- Institute of Horticulture, Lithuanian Research Centre for Agriculture and Forestry, 54333, Babtai, Lithuania
| | - Jonas Viškelis
- Institute of Horticulture, Lithuanian Research Centre for Agriculture and Forestry, 54333, Babtai, Lithuania
| | - Dalia Urbonaviciene
- Institute of Horticulture, Lithuanian Research Centre for Agriculture and Forestry, 54333, Babtai, Lithuania
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Nutrition and Altitude: Strategies to Enhance Adaptation, Improve Performance and Maintain Health: A Narrative Review. Sports Med 2020; 49:169-184. [PMID: 31691928 PMCID: PMC6901429 DOI: 10.1007/s40279-019-01159-w] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Training at low to moderate altitudes (~ 1600-2400 m) is a common approach used by endurance athletes to provide a distinctive environmental stressor to augment training stimulus in the anticipation of increasing subsequent altitude- and sea-level-based performance. Despite some scientific progress being made on the impact of various nutrition-related changes in physiology and associated interventions at mountaineering altitudes (> 3000 m), the impact of nutrition and/or supplements on further optimization of these hypoxic adaptations at low-moderate altitudes is only an emerging topic. Within this narrative review we have highlighted six major themes involving nutrition: altered energy availability, iron, carbohydrate, hydration, antioxidant requirements and various performance supplements. Of these issues, emerging data suggest that particular attention be given to the potential risk for poor energy availability and increased iron requirements at the altitudes typical of elite athlete training (~ 1600-2400 m) to interfere with optimal adaptations. Furthermore, the safest way to address the possible increase in oxidative stress associated with altitude exposure is via the consumption of antioxidant-rich foods rather than high-dose antioxidant supplements. Meanwhile, many other important questions regarding nutrition and altitude training remain to be answered. At the elite level of sport where the differences between winning and losing are incredibly small, the strategic use of nutritional interventions to enhance the adaptations to altitude training provides an important consideration in the search for optimal performance.
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Mujika I, Sharma AP, Stellingwerff T. Contemporary Periodization of Altitude Training for Elite Endurance Athletes: A Narrative Review. Sports Med 2020; 49:1651-1669. [PMID: 31452130 DOI: 10.1007/s40279-019-01165-y] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Since the 1960s there has been an escalation in the purposeful utilization of altitude to enhance endurance athletic performance. This has been mirrored by a parallel intensification in research pursuits to elucidate hypoxia-induced adaptive mechanisms and substantiate optimal altitude protocols (e.g., hypoxic dose, duration, timing, and confounding factors such as training load periodization, health status, individual response, and nutritional considerations). The majority of the research and the field-based rationale for altitude has focused on hematological outcomes, where hypoxia causes an increased erythropoietic response resulting in augmented hemoglobin mass. Hypoxia-induced non-hematological adaptations, such as mitochondrial gene expression and enhanced muscle buffering capacity may also impact athletic performance, but research in elite endurance athletes is limited. However, despite significant scientific progress in our understanding of hypobaric hypoxia (natural altitude) and normobaric hypoxia (simulated altitude), elite endurance athletes and coaches still tend to be trailblazers at the coal face of cutting-edge altitude application to optimize individual performance, and they already implement novel altitude training interventions and progressive periodization and monitoring approaches. Published and field-based data strongly suggest that altitude training in elite endurance athletes should follow a long- and short-term periodized approach, integrating exercise training and recovery manipulation, performance peaking, adaptation monitoring, nutritional approaches, and the use of normobaric hypoxia in conjunction with terrestrial altitude. Future research should focus on the long-term effects of accumulated altitude training through repeated exposures, the interactions between altitude and other components of a periodized approach to elite athletic preparation, and the time course of non-hematological hypoxic adaptation and de-adaptation, and the potential differences in exercise-induced altitude adaptations between different modes of exercise.
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Affiliation(s)
- Iñigo Mujika
- Department of Physiology, Faculty of Medicine and Odontology, University of the Basque Country, Leioa, Basque Country, Spain. .,Exercise Science Laboratory, School of Kinesiology, Faculty of Medicine, Universidad Finis Terrae, Santiago, Chile.
| | - Avish P Sharma
- Griffith Sports Physiology and Performance, School of Allied Health Sciences, Griffith University, Gold Coast, QLD, Australia.,Triathlon Australia, Burleigh Heads, QLD, Australia
| | - Trent Stellingwerff
- Canadian Sport Institute-Pacific, Victoria, BC, Canada.,Department of Exercise Science, Physical and Health Education, University of Victoria, Victoria, BC, Canada
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Zamani H, de Joode MEJR, Hossein IJ, Henckens NFT, Guggeis MA, Berends JE, de Kok TMCM, van Breda SGJ. The benefits and risks of beetroot juice consumption: a systematic review. Crit Rev Food Sci Nutr 2020; 61:788-804. [PMID: 32292042 DOI: 10.1080/10408398.2020.1746629] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Beetroot juice (BRJ) has become increasingly popular amongst athletes aiming to improve sport performances. BRJ contains high concentrations of nitrate, which can be converted into nitric oxide (NO) after consumption. NO has various functions in the human body, including a vasodilatory effect, which reduces blood pressure and increases oxygen- and nutrient delivery to various organs. These effects indicate that BRJ may have relevant applications in prevention and treatment of cardiovascular disease. Furthermore, the consumption of BRJ also has an impact on oxygen delivery to skeletal muscles, muscle efficiency, tolerance and endurance and may thus have a positive impact on sports performances. Aside from the beneficial aspects of BRJ consumption, there may also be potential health risks. Drinking BRJ may easily increase nitrate intake above the acceptable daily intake, which is known to stimulate the endogenous formation of N-nitroso compounds (NOC's), a class of compounds that is known to be carcinogenic and that may also induce several other adverse effects. Compared to studies on the beneficial effects, the amount of data and literature on the negative effects of BRJ is rather limited, and should be increased in order to perform a balanced risk assessment.
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Affiliation(s)
- H Zamani
- Department of Toxicogenomics, GROW-school for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, the Netherlands
| | - M E J R de Joode
- Department of Toxicogenomics, GROW-school for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, the Netherlands
| | - I J Hossein
- Department of Toxicogenomics, GROW-school for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, the Netherlands
| | - N F T Henckens
- Department of Toxicogenomics, GROW-school for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, the Netherlands
| | - M A Guggeis
- Department of Toxicogenomics, GROW-school for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, the Netherlands
| | - J E Berends
- Department of Toxicogenomics, GROW-school for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, the Netherlands
| | - T M C M de Kok
- Department of Toxicogenomics, GROW-school for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, the Netherlands
| | - S G J van Breda
- Department of Toxicogenomics, GROW-school for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, the Netherlands
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Cocksedge SP, Breese BC, Morgan PT, Nogueira L, Thompson C, Wylie LJ, Jones AM, Bailey SJ. Influence of muscle oxygenation and nitrate-rich beetroot juice supplementation on O 2 uptake kinetics and exercise tolerance. Nitric Oxide 2020; 99:25-33. [PMID: 32272260 DOI: 10.1016/j.niox.2020.03.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 03/24/2020] [Accepted: 03/25/2020] [Indexed: 11/25/2022]
Abstract
We tested the hypothesis that acute supplementation with nitrate (NO3-)-rich beetroot juice (BR) would improve quadriceps muscle oxygenation, pulmonary oxygen uptake (V˙O2) kinetics and exercise tolerance (Tlim) in normoxia and that these improvements would be augmented in hypoxia and attenuated in hyperoxia. In a randomised, double-blind, cross-over study, ten healthy males completed two-step cycle tests to Tlim following acute consumption of 210 mL BR (18.6 mmol NO3-) or NO3--depleted beetroot juice placebo (PL; 0.12 mmol NO3-). These tests were completed in normobaric normoxia [fraction of inspired oxygen (FIO2): 21%], hypoxia (FIO2: 15%) and hyperoxia (FIO2: 40%). Pulmonary V˙O2 and quadriceps tissue oxygenation index (TOI), derived from multi-channel near-infrared spectroscopy, were measured during all trials. Plasma [nitrite] was higher in all BR compared to all PL trials (P < 0.05). Quadriceps TOI was higher in normoxia compared to hypoxia (P < 0.05) and higher in hyperoxia compared to hypoxia and normoxia (P < 0.05). Tlim was improved after BR compared to PL ingestion in the hypoxic trials (250 ± 44 vs. 231 ± 41 s; P = 0.006; d = 1.13), with the magnitude of improvement being negatively correlated with quadriceps TOI at Tlim (r = -0.78; P < 0.05). Tlim was not improved following BR ingestion in normoxia (BR: 364 ± 98 vs. PL: 344 ± 78 s; P = 0.087, d = 0.61) or hyperoxia (BR: 492 ± 212 vs. PL: 472 ± 196 s; P = 0.273, d = 0.37). BR ingestion increased peak V˙O2 in hypoxia (P < 0.05), but not normoxia or hyperoxia (P > 0.05). These findings indicate that BR supplementation is more likely to improve Tlim and peak V˙O2 in situations when skeletal muscle is more hypoxic.
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Affiliation(s)
- Stuart P Cocksedge
- Sport and Health Sciences, College of Life and Environmental Sciences, St. Luke's Campus, University of Exeter, Heavitree Road, Exeter, UK; School of Sport, Exercise and Health Sciences, Loughborough University, Epinal Way, Loughborough, UK
| | - Brynmor C Breese
- School of Biological and Biomedical Sciences, Portland Square Building, Plymouth University, Drake Circus, Plymouth, UK
| | - Paul T Morgan
- Sport and Health Sciences, College of Life and Environmental Sciences, St. Luke's Campus, University of Exeter, Heavitree Road, Exeter, UK
| | - Leonardo Nogueira
- Section of Physiology, Division of Pulmonary, Critical Care & Sleep Medicine, Department of Medicine, University of California, San Diego, CA, USA; Instituto de Bioquímica Médica Leopoldo de Meis (Medical Biochemistry Institute Leopoldo de Meis), Federal University of Rio de Janeiro, RJ, Brazil
| | - Christopher Thompson
- Sport and Health Sciences, College of Life and Environmental Sciences, St. Luke's Campus, University of Exeter, Heavitree Road, Exeter, UK
| | - Lee J Wylie
- Sport and Health Sciences, College of Life and Environmental Sciences, St. Luke's Campus, University of Exeter, Heavitree Road, Exeter, UK
| | - Andrew M Jones
- Sport and Health Sciences, College of Life and Environmental Sciences, St. Luke's Campus, University of Exeter, Heavitree Road, Exeter, UK
| | - Stephen J Bailey
- Sport and Health Sciences, College of Life and Environmental Sciences, St. Luke's Campus, University of Exeter, Heavitree Road, Exeter, UK; School of Sport, Exercise and Health Sciences, Loughborough University, Epinal Way, Loughborough, UK.
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Matsuo H, Kubota M, Shimada S, Kitade I, Matsumura M, Nonoyama T, Koie Y, Naruse H, Takahashi A, Oki H, Kokubo Y, Matsumine A. The Effect of Static Stretching Duration on Muscle Blood Volume and Oxygenation. J Strength Cond Res 2020; 36:379-385. [PMID: 32028461 DOI: 10.1519/jsc.0000000000003457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Matsuo, H, Kubota, M, Shimada, S, Kitade, I, Matsumura, M, Nonoyama, T, Koie, Y, Naruse, H, Takahashi, A, Oki, H, Kokubo, Y, and Matsumine, A. The effect of static stretching duration on muscle blood volume and oxygenation. J Strength Cond Res XX(X): 000-000, 2020-Muscle blood volume increases due to stretching; however, the minimum duration of stretching to sustainably increase the muscle blood volume after stretching has not yet been elucidated. This study examined whether the duration of static stretching influenced the muscle blood volume and oxygenation. Ten healthy male subjects participated in this controlled laboratory study. Static stretching of the gastrocnemius muscle was performed for 5 durations (20 seconds, and 1, 2, 5, and 10 minutes). Changes in both the total-Hb (ΔtHb), as an index of blood volume, and tissue oxygenation index (ΔTOI) from baseline were determined using near-infrared spectroscopy. Both the ΔtHb and ΔTOI decreased during stretching and increased after stretching. The minimum value of ΔtHb during stretching did not differ in each of the 5 durations, but minimum ΔTOI progressively decreased with longer durations of stretching. The peak value of ΔtHb after stretching increased with longer durations of stretching. The value of ΔtHb at 5 minutes after the end of stretching increased with more than 2 minutes of stretching compared with 20 seconds of stretching, although the value of ΔtHb did not significantly differ between the 2, 5, and 10 minutes' durations. These findings suggest that a longer duration of stretching elicits a decrease in muscle oxygenation during stretching, and an increase in both the muscle blood volume and oxygenation after stretching. The results indicated that the minimum duration of stretching to sustain an increase in the muscle blood volume after stretching is 2 minutes.
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Affiliation(s)
- Hideaki Matsuo
- Division of Physical Therapy and Rehabilitation Medicine, University of Fukui Hospital, Fukui, Japan
| | - Masafumi Kubota
- Division of Physical Therapy and Rehabilitation Medicine, University of Fukui Hospital, Fukui, Japan
| | - Seiichiro Shimada
- Division of Physical Therapy and Rehabilitation Medicine, University of Fukui Hospital, Fukui, Japan
| | - Ippei Kitade
- Division of Physical Therapy and Rehabilitation Medicine, University of Fukui Hospital, Fukui, Japan
| | - Mayumi Matsumura
- Division of Physical Therapy and Rehabilitation Medicine, University of Fukui Hospital, Fukui, Japan
| | - Tadayoshi Nonoyama
- Division of Physical Therapy and Rehabilitation Medicine, University of Fukui Hospital, Fukui, Japan
| | - Yusuke Koie
- Division of Physical Therapy and Rehabilitation Medicine, University of Fukui Hospital, Fukui, Japan
| | - Hiroaki Naruse
- Division of Physical Therapy and Rehabilitation Medicine, University of Fukui Hospital, Fukui, Japan
| | - Ai Takahashi
- Department of Orthopedics and Rehabilitation Medicine, Faculty of Medical Sciences, University of Fukui, Fukui, Japan
| | - Hisashi Oki
- Department of Orthopedics and Rehabilitation Medicine, Faculty of Medical Sciences, University of Fukui, Fukui, Japan
| | - Yasuo Kokubo
- Department of Orthopedics and Rehabilitation Medicine, Faculty of Medical Sciences, University of Fukui, Fukui, Japan
| | - Akihiko Matsumine
- Department of Orthopedics and Rehabilitation Medicine, Faculty of Medical Sciences, University of Fukui, Fukui, Japan
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Franko E, Ezra M, Crockett DC, Joly O, Pattinson K. Effect of nitrite on the electroencephalographic activity in the healthy brain. Nitric Oxide 2019; 90:47-54. [DOI: 10.1016/j.niox.2019.06.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 05/06/2019] [Accepted: 06/23/2019] [Indexed: 10/26/2022]
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Supplementary Nitric Oxide Donors and Exercise as Potential Means to Improve Vascular Health in People with Type 1 Diabetes: Yes to NO? Nutrients 2019; 11:nu11071571. [PMID: 31336832 PMCID: PMC6682901 DOI: 10.3390/nu11071571] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 06/26/2019] [Accepted: 07/10/2019] [Indexed: 12/16/2022] Open
Abstract
Type 1 diabetes (T1D) is associated with a greater occurrence of cardiovascular pathologies. Vascular dysfunction has been shown at the level of the endothelial layers and failure to maintain a continuous pool of circulating nitric oxide (NO) has been implicated in the progression of poor vascular health. Biochemically, NO can be produced via two distinct yet inter-related pathways that involve an upregulation in the enzymatic activity of nitric oxide synthase (NOS). These pathways can be split into an endogenous oxygen-dependent pathway i.e., the catabolism of the amino acid L-arginine to L-citrulline concurrently yielding NO in the process, and an exogenous oxygen-independent one i.e., the conversion of exogenous inorganic nitrate to nitrite and subsequently NO in a stepwise fashion. Although a body of research has explored the vascular responses to exercise and/or compounds known to stimulate NOS and subsequently NO production, there is little research applying these findings to individuals with T1D, for whom preventative strategies that alleviate or at least temper vascular pathologies are critical foci for long-term risk mitigation. This review addresses the proposed mechanisms responsible for vascular dysfunction, before exploring the potential mechanisms by which exercise, and two supplementary NO donors may provide vascular benefits in T1D.
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Abstract
Nitric oxide (NO) plays a plethora of important roles in the human body. Insufficient production of NO (for example, during older age and in various disease conditions) can adversely impact health and physical performance. In addition to its endogenous production through the oxidation of l-arginine, NO can be formed nonenzymatically via the reduction of nitrate and nitrite, and the storage of these anions can be augmented by the consumption of nitrate-rich foodstuffs such as green leafy vegetables. Recent studies indicate that dietary nitrate supplementation, administered most commonly in the form of beetroot juice, can ( a) improve muscle efficiency by reducing the O2 cost of submaximal exercise and thereby improve endurance exercise performance and ( b) enhance skeletal muscle contractile function and thereby improve muscle power and sprint exercise performance. This review describes the physiological mechanisms potentially responsible for these effects, outlines the circumstances in which ergogenic effects are most likely to be evident, and discusses the effects of dietary nitrate supplementation on physical performance in a range of human populations.
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Affiliation(s)
- Andrew M Jones
- Department of Sport and Health Sciences, University of Exeter, Exeter EX1 2LU, United Kingdom;
| | - Christopher Thompson
- Department of Sport and Health Sciences, University of Exeter, Exeter EX1 2LU, United Kingdom;
| | - Lee J Wylie
- Department of Sport and Health Sciences, University of Exeter, Exeter EX1 2LU, United Kingdom;
| | - Anni Vanhatalo
- Department of Sport and Health Sciences, University of Exeter, Exeter EX1 2LU, United Kingdom;
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Dobashi S, Koyama K, Endo J, Kiuchi M, Horiuchi M. Impact of Dietary Nitrate Supplementation on Executive Function During Hypoxic Exercise. High Alt Med Biol 2019; 20:187-191. [DOI: 10.1089/ham.2018.0114] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Affiliation(s)
- Shohei Dobashi
- Integrated Graduate School, Department of Medicine, Engineering, and Agricultural Sciences, University of Yamanashi, Kofu, Japan
- Japan Society for the Promotion of Science, Tokyo, Japan
| | - Katsuhiro Koyama
- Graduate School Department of Interdisciplinary Research, University of Yamanashi, Kofu, Japan
| | - Junko Endo
- Division of Human Environmental Science, Mt. Fuji Research Institute, Fujiyoshida, Japan
| | - Masataka Kiuchi
- Graduate School, Department of Education, University of Yamanashi, Kofu, Japan
| | - Masahiro Horiuchi
- Division of Human Environmental Science, Mt. Fuji Research Institute, Fujiyoshida, Japan
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Le Roux-Mallouf T, Pelen F, Vallejo A, Halimaoui I, Doutreleau S, Verges S. Effect of chronic nitrate and citrulline supplementation on vascular function and exercise performance in older individuals. Aging (Albany NY) 2019; 11:3315-3332. [PMID: 31141497 PMCID: PMC6555465 DOI: 10.18632/aging.101984] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 05/17/2019] [Indexed: 12/11/2022]
Abstract
Increased nitric oxide (NO) bioavailability may improve exercise performance and vascular function. It remains unclear whether older adults who experience a decreased NO bioavailability may benefit from chronic NO precursor supplementation. This randomised, double-blind, trial aims to assess the effect of chronic NO precursor intake on vascular function and exercise performance in older adults (60-70 years old). Twenty-four healthy older adults (12 females) performed vascular function assessment and both local (knee extensions) and whole-body (incremental cycling) exercise tests to exhaustion before and after one month of daily intake of a placebo (PLA) or a nitrate-rich salad and citrulline (N+C, 520mg nitrate and 6g citrulline) drink. Arterial blood pressure (BP) and stiffness, post-ischemic, hypercapnic and hypoxic vascular responses were evaluated. Prefrontal cortex and quadriceps oxygenation was monitored by near-infrared spectroscopy. N+C supplementation reduced mean BP (-3.3mmHg; p=0.047) without altering other parameters of vascular function and oxygenation kinetics. N+C supplementation reduced heart rate and oxygen consumption during submaximal cycling and increased maximal power output by 5.2% (p<0.05), but had no effect on knee extension exercise performance. These results suggest that chronic NO precursor supplementation in healthy older individuals can reduce resting BP and increase cycling performance by improving cardiorespiratory responses.
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Affiliation(s)
| | - Felix Pelen
- Université Grenoble Alpes, Inserm, HP2 Laboratory, Grenoble F-38000, France
| | - Angela Vallejo
- Université Grenoble Alpes, Inserm, HP2 Laboratory, Grenoble F-38000, France
| | - Idir Halimaoui
- Université Grenoble Alpes, Inserm, HP2 Laboratory, Grenoble F-38000, France
| | - Stéphane Doutreleau
- Université Grenoble Alpes, Inserm, HP2 Laboratory, Grenoble F-38000, France
- Sport and Pathologies Unit, Grenoble Alpes University Hospital, Hôpital Michallon, Grenoble F-38042, France
| | - Samuel Verges
- Université Grenoble Alpes, Inserm, HP2 Laboratory, Grenoble F-38000, France
- Sport and Pathologies Unit, Grenoble Alpes University Hospital, Hôpital Michallon, Grenoble F-38042, France
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Le Roux-Mallouf T, Laurent J, Besset D, Marillier M, Larribaut J, Belaidi E, Corne C, Doutreleau S, Verges S. Effects of acute nitric oxide precursor intake on peripheral and central fatigue during knee extensions in healthy men. Exp Physiol 2019; 104:1100-1114. [PMID: 31004378 DOI: 10.1113/ep087493] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Accepted: 04/18/2019] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the central question of this study? What is the effect of acute NO precursor intake on vascular function, muscle and cerebral oxygenation and peripheral and central neuromuscular fatigue during knee-extension exercise? What is the main finding and its importance? Acute NO precursor ingestion increases the plasma concentrations of NO precursors (nitrate, arginine and citrulline) and enhances post-ischaemic vasodilatation, but has no significant effect on muscle and cerebral oxygenation, peripheral and central mechanisms of neuromuscular fatigue and, consequently, does not improve exercise performance. ABSTRACT Nitric oxide (NO) plays an important role in matching blood flow to oxygen demand in the brain and contracting muscles during exercise. Previous studies have shown that increasing NO bioavailability can improve muscle function. The aim of this study was to assess the effect of acute NO precursor intake on muscle and cerebral oxygenation and on peripheral and central neuromuscular fatigue during exercise. In four experimental sessions, 15 healthy men performed a thigh ischaemia-reperfusion test followed by submaximal isometric knee extensions (5 s on-4 s off; 45% of maximal voluntary contraction) until task failure. In each session, subjects drank a nitrate-rich beetroot juice containing 520 mg nitrate (N), N and citrulline (6 g; N+C), N and arginine (6 g; N+A) or a placebo (PLA). Prefrontal cortex and quadriceps near-infrared spectroscopy parameters were monitored continuously. Transcranial magnetic stimulation and femoral nerve electrical stimulation were used to assess central and peripheral determinants of fatigue. The post-ischaemic increase in thigh blood total haemoglobin concentration was larger in N (10.1 ± 3.7 mmol) and N+C (10.9 ± 3.3 mmol) compared with PLA (8.2 ± 2.7 mmol; P < 0.05). Nitric oxide precursors had no significant effect on muscle and cerebral oxygenation or on peripheral and central mechanisms of neuromuscular fatigue during exercise. The total number of knee extensions did not differ between sessions (N, 71.9 ± 33.2; N+A, 73.3 ± 39.4; N+C, 74.6 ± 34.0; PLA, 71.8 ± 39.9; P > 0.05). In contrast to the post-ischaemic hyperaemic response, NO bioavailability in healthy subjects might not be the limiting factor for tissue perfusion and oxygenation during submaximal knee extensions to task failure.
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Affiliation(s)
| | - Julien Laurent
- Laboratoire HP2 (U1042 INSERM), Université, Grenoble Alpes, Grenoble, France
| | - Dimitri Besset
- Laboratoire HP2 (U1042 INSERM), Université, Grenoble Alpes, Grenoble, France
| | - Mathieu Marillier
- Laboratoire HP2 (U1042 INSERM), Université, Grenoble Alpes, Grenoble, France
| | - Julie Larribaut
- Laboratoire HP2 (U1042 INSERM), Université, Grenoble Alpes, Grenoble, France
| | - Elise Belaidi
- Laboratoire HP2 (U1042 INSERM), Université, Grenoble Alpes, Grenoble, France
| | - Christelle Corne
- Inherited Metabolic Disease Laboratory, Department of Biochemistry, Molecular and Environmental Toxicology Biology, Biology and Pathology Institute, Hôpital Michallon, Grenoble, France
| | - Stéphane Doutreleau
- Laboratoire HP2 (U1042 INSERM), Université, Grenoble Alpes, Grenoble, France.,Sport and Pathologies Unit, Grenoble Alpes University Hospital, Hôpital Michallon, Grenoble, France
| | - Samuel Verges
- Laboratoire HP2 (U1042 INSERM), Université, Grenoble Alpes, Grenoble, France.,Sport and Pathologies Unit, Grenoble Alpes University Hospital, Hôpital Michallon, Grenoble, France
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Nitrate supplementation improves physical performance specifically in non-athletes during prolonged open-ended tests: a systematic review and meta-analysis. Br J Nutr 2019; 119:636-657. [PMID: 29553034 DOI: 10.1017/s0007114518000132] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Nitrate (NO3 -) is an ergogenic nutritional supplement that is widely used to improve physical performance. However, the effectiveness of NO3 - supplementation has not been systematically investigated in individuals with different physical fitness levels. The present study analysed whether different fitness levels (non-athletes v. athletes or classification of performance levels), duration of the test used to measure performance (short v. long duration) and the test protocol (time trials v. open-ended tests v. graded-exercise tests) influence the effects of NO3 - supplementation on performance. This systematic review and meta-analysis was conducted and reported according to the guidelines outlined in the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement. A systematic search of electronic databases, including PubMed, Web of Science, SPORTDiscus and ProQuest, was performed in August 2017. On the basis of the search and inclusion criteria, fifty-four and fifty-three placebo-controlled studies evaluating the effects of NO3 - supplementation on performance in humans were included in the systematic review and meta-analysis, respectively. NO3 - supplementation was ergogenic in non-athletes (mean effect size (ES) 0·25; 95 % CI 0·11, 0·38), particularly in evaluations of performance using long-duration open-ended tests (ES 0·47; 95 % CI 0·23, 0·71). In contrast, NO3 - supplementation did not enhance the performance of athletes (ES 0·04; 95 % CI -0·05, 0·15). After objectively classifying the participants into different performance levels, the frequency of trials showing ergogenic effects in individuals classified at lower levels was higher than that in individuals classified at higher levels. Thus, the present study indicates that dietary NO3 - supplementation improves physical performance in non-athletes, particularly during long-duration open-ended tests.
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Effect of New Zealand Blackcurrant Extract on Cycling Performance and Substrate Oxidation in Normobaric Hypoxia in Trained Cyclists. Sports (Basel) 2019; 7:sports7030067. [PMID: 30884866 PMCID: PMC6473752 DOI: 10.3390/sports7030067] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 03/03/2019] [Accepted: 03/13/2019] [Indexed: 11/16/2022] Open
Abstract
New Zealand blackcurrant (NZBC) extract enhanced exercise-induced fat oxidation and 16.1 km cycling time trial (TT) in normobaric normoxia. The effect of NZBC extract on physiological and metabolic responses was examined during steady state cycling and a 16.1 km TT in normobaric hypoxia. This study used a randomized, double-blind, crossover design. Eleven healthy male cyclists (age: 38 ± 11 y, height: 179 ± 4 cm, body mass: 76 ± 8 kg, V ˙ O2max: 47 ± 5 mL·kg-1·min-1, mean ± SD) ingested NZBC extract (600 mg·day-1 CurraNZ® containing 210 mg anthocyanins) or a placebo (600 mg microcrystalline cellulose M102) for seven days (washout 14 days) and performed a steady state cycling test (3 × 10 min at 45%, 55% and 65% V ˙ O2max) followed by a 16.1 km TT at a simulated altitude of ~2500 meters (~15% of O₂). Indirect calorimetry was used to measure substrate oxidation during steady state cycling. Intake of NZBC extract had no effect on blood glucose and lactate, heart rate, substrate oxidation, and respiratory exchange ratio during steady state cycling at 45%, 55% and 65% V ˙ O2max, and on 16.1 km TT performance (placebo: 1685 ± 92 s, NZBC extract: 1685 ± 99 s, P = 0.97). Seven days intake of New Zealand blackcurrant extract does not change exercise-induced metabolic responses and 16.1 km cycling time trial performance for moderately endurance-trained men in normobaric hypoxia.
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Carriker CR, Rombach P, Stevens BM, Vaughan RA, Gibson AL. Acute dietary nitrate supplementation does not attenuate oxidative stress or the hemodynamic response during submaximal exercise in hypobaric hypoxia. Appl Physiol Nutr Metab 2018; 43:1268-1274. [DOI: 10.1139/apnm-2017-0813] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The purpose of this study was to investigate changes in oxidative stress, arterial oxygen saturation (SaO2), blood pressure (BP), and heart rate (HR) during exercise in hypobaric hypoxia following acute dietary nitrate supplementation. Nine well-trained (maximal oxygen consumption, 60.8 ± 7.8 mL·kg−1·min−1) males (age, 29 ± 7 years) visited the laboratory on 3 occasions, each separated by 1 week. Visit 1 included a maximal aerobic cycling test and five 5-min increasing-intensity exercise bouts in a normobaric environment (1600 m). A single dose of either a nitrate-depleted placebo (PL) or a nitrate-rich beverage (NR; 12.8 mmol nitrate) was consumed 2.5 h prior to exercise during visits 2 and 3 (3500 m) in a double-blind, placebo-controlled, crossover study consisting of a 5-min cycling warm-up and 4 bouts, each 5 min in duration, separated by 4-min periods of passive rest. Exercise wattages were determined during visit 1 and corresponded to 25%, 40%, 50%, 60%, and 70% of normobaric maximal oxygen consumption. Catalase and 8-isoprostane were measured before and after exercise (immediately before and 1 h postexercise, respectively). NR increased plasma nitrite (1.53 ± 0.83 μmol·L−1) compared with PL (0.88 ± 0.56 μmol·L−1) (p < 0.05). In both conditions, postexercise (3500 m) 8-isoprostane (PL, 23.49 ± 3.38 to 60.90 ± 14.95 pg·mL−1; NR, 23.23 ± 4.12 to 52.11 ± 19.76 pg·mL−1) and catalase (PL, 63.89 ± 25.69 to 128.15 ± 41.80 mmol·min−1·mL−1; NR, 78.89 ± 30.95 to 109.96 ± 35.05 mmol·min−1·mL−1) were elevated compared with baseline resting values (p < 0.05). However, both 8-isoprostane and catalase were similar in the 2 groups (PL and NR) (p = 0.217 and p = 0.080, respectively). We concluded that an acute, pre-exercise dose of dietary nitrate yielded no beneficial changes in oxidative stress, SaO2, BP, or HR in healthy, aerobically fit men exercising at 3500 m.
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Affiliation(s)
- Colin R. Carriker
- Department of Exercise Science, High Point University, High Point, NC 27268, USA
- Department of Health, Exercise and Sports Sciences, University of New Mexico, Albuquerque, NM 87131, USA
| | - Paige Rombach
- Department of Exercise Science, High Point University, High Point, NC 27268, USA
| | - Brooke M. Stevens
- Department of Exercise Science, High Point University, High Point, NC 27268, USA
| | - Roger A. Vaughan
- Department of Exercise Science, High Point University, High Point, NC 27268, USA
| | - Ann L. Gibson
- Department of Health, Exercise and Sports Sciences, University of New Mexico, Albuquerque, NM 87131, USA
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Shannon OM, McGawley K, Nybäck L, Duckworth L, Barlow MJ, Woods D, Siervo M, O'Hara JP. "Beet-ing" the Mountain: A Review of the Physiological and Performance Effects of Dietary Nitrate Supplementation at Simulated and Terrestrial Altitude. Sports Med 2018; 47:2155-2169. [PMID: 28577258 PMCID: PMC5633647 DOI: 10.1007/s40279-017-0744-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Exposure to altitude results in multiple physiological consequences. These include, but are not limited to, a reduced maximal oxygen consumption, drop in arterial oxygen saturation, and increase in muscle metabolic perturbations at a fixed sub-maximal work rate. Exercise capacity during fixed work rate or incremental exercise and time-trial performance are also impaired at altitude relative to sea level. Recently, dietary nitrate (NO3−) supplementation has attracted considerable interest as a nutritional aid during altitude exposure. In this review, we summarise and critically evaluate the physiological and performance effects of dietary NO3− supplementation during exposure to simulated and terrestrial altitude. Previous investigations at simulated altitude indicate that NO3− supplementation may reduce the oxygen cost of exercise, elevate arterial and tissue oxygen saturation, improve muscle metabolic function, and enhance exercise capacity/performance. Conversely, current evidence suggests that NO3− supplementation does not augment the training response at simulated altitude. Few studies have evaluated the effects of NO3− at terrestrial altitude. Current evidence indicates potential improvements in endothelial function at terrestrial altitude following NO3− supplementation. No effects of NO3− supplementation have been observed on oxygen consumption or arterial oxygen saturation at terrestrial altitude, although further research is warranted. Limitations of the present body of literature are discussed, and directions for future research are provided.
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Affiliation(s)
- Oliver Michael Shannon
- Research Institute for Sport, Physical Activity, and Leisure, Leeds Beckett University, Leeds, LS6 3QS, UK.
| | - Kerry McGawley
- Swedish Winter Sports Research Centre, Department of Health Sciences, Mid Sweden University, Östersund, Sweden
| | - Linn Nybäck
- Swedish Winter Sports Research Centre, Department of Health Sciences, Mid Sweden University, Östersund, Sweden
| | - Lauren Duckworth
- Research Institute for Sport, Physical Activity, and Leisure, Leeds Beckett University, Leeds, LS6 3QS, UK
| | - Matthew John Barlow
- Research Institute for Sport, Physical Activity, and Leisure, Leeds Beckett University, Leeds, LS6 3QS, UK
| | - David Woods
- Research Institute for Sport, Physical Activity, and Leisure, Leeds Beckett University, Leeds, LS6 3QS, UK.,Defence Medical Services, Royal Centre for Defence Medicine, Birmingham, B152TH, UK
| | - Mario Siervo
- Institute of Cellular Medicine, University of Newcastle, Newcastle upon Tyne, NE45PL, UK
| | - John Paul O'Hara
- Research Institute for Sport, Physical Activity, and Leisure, Leeds Beckett University, Leeds, LS6 3QS, UK
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Van De Walle GP, Vukovich MD. The Effect of Nitrate Supplementation on Exercise Tolerance and Performance: A Systematic Review and Meta-Analysis. J Strength Cond Res 2018; 32:1796-1808. [PMID: 29786633 DOI: 10.1519/jsc.0000000000002046] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Van De Walle, GP and Vukovich, MD. The effect of nitrate supplementation on exercise tolerance and performance: a systematic review and meta-analysis. J Strength Cond Res 32(6): 1796-1808, 2018-The purpose of this article was to systematically review the current literature and evaluate the overall efficacy of nitrate supplementation on exercise tolerance and performance by meta-analysis. Studies were eligible for inclusion if they met the following criteria: (a) were an experimental trial published in an English peer-reviewed journal; (b) compared the effects of inorganic nitrate consumption with a non-bioactive supplement control or placebo; (c) used a quantifiable measure of exercise performance; and (d) was carried out in apparently healthy participants without disease. A total of 29 studies were identified that investigated the effects of nitrate supplementation on exercise tolerance or performance in accordance with the criteria outlined. Analysis using time to exhaustion as the outcome variable revealed a significant effect of nitrate supplementation on exercise tolerance (ES = 0.28; 95% confidence interval [CI]: 0.08-0.47; p = 0.006) compared with placebo. Analysis using time to complete a specific distance as the outcome variable revealed no significant effect of nitrate supplementation on exercise performance (ES = -0.05; 95% CI: -0.28 to 0.17; p = 0.64) compared with placebo. Nitrate supplementation is likely to improve exercise tolerance and capacity that may improve exercise performance. More research is required to determine the optimal dose and duration of nitrate supplementation. It would also be important to consider the type of athlete performing the exercise and the duration, intensity, and mode of the exercise performed because these factors are likely to influence the efficacy of nitrate supplementation.
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Affiliation(s)
- Gavin P Van De Walle
- Department of Health and Nutritional Sciences, South Dakota State University, Brookings, South Dakota
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A single dose of beetroot juice improves endothelial function but not tissue oxygenation in pregnant women: a randomised clinical trial. Br J Nutr 2018; 120:1006-1013. [PMID: 30229712 DOI: 10.1017/s0007114518002441] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Beetroot juice (BJ) consumption has been associated with improved cardiovascular health owing to an increase in NO bioconversion. This study evaluates the effect of BJ consumption on macrovascular endothelial function (flow-mediated dilation (FMD)) and muscle oxygen saturation (StO2) parameters in pregnant women within a randomised, crossover, double-blind design in which twelve pregnant women consumed a single dose (140 ml) of BJ or placebo (PLA). Urinary nitrate was assessed before (T0) and 150 min after BJ/PLA consumption. FMD was used to evaluate macrovascular endothelial function, and near-IR spectroscopy was used to evaluate muscle StO2 parameters during the occlusion and reperfusion phases, which were taken at baseline (PRE) and 120 and 140 min after BJ/PLA consumption, respectively. A significant increase in urinary nitrate was observed at 150 min after BJ consumption when compared with T0 (BJ: 0·20 (sd 0·13) v. T0: 0·02 (sd 0·00), P=0·000) and PLA intervention (PLA: 0·02 (sd 0·00), P=0·001). FMD improved after BJ consumption when compared with PRE (BJ: 11·00 (sd 1·67) v. PRE: 5·53 (sd 1·17), P=0·000) and PLA (5·34 (sd 1·31), P=0·000). No significant difference between PLA and PRE in FMD (P=1·000) was observed. In StO2 parameters, a difference was not observed after BJ consumption compared with PRE and PLA intervention. The data demonstrate that a single dose of 140 ml of BJ consumption improves macrovascular endothelial function, but not StO2 parameters.
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Kerley CP, James PE, McGowan A, Faul J, Cormican L. Dietary nitrate improved exercise capacity in COPD but not blood pressure or pulmonary function: a 2 week, double-blind randomised, placebo-controlled crossover trial. Int J Food Sci Nutr 2018; 70:222-231. [PMID: 30188220 DOI: 10.1080/09637486.2018.1492521] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Dietary nitrate may improve exercise tolerance in some healthy and clinical populations. Existing data regarding dietary nitrate in COPD is inconsistent. We conducted a 14d double-blind, randomised, placebo-controlled, crossover trial of daily nitrate-rich beetroot juice (BRJ; 12.9 mmol) versus nitrate-depleted BRJ (PL; 0.5 mmol). At baseline and after each condition, we assessed functional capacity (incremental shuttle walk test; ISWT), ambulatory blood pressure, pulmonary function, quality of life as well as exhaled nitric oxide (eNO), and plasma nitrate/nitrite (NOx). Eight subjects with COPD completed the trial. BRJ supplementation was associated with significantly increased NOx (p < .05) and a 14.6% increase in ISWT distance (+56 m, p = .00004) as well as a trend towards increased eNO compared to PL. There was no other differences. Dietary nitrate appears to have ergogenic effect in subjects with mild-moderate COPD. This effect does not appear to be related to altering blood pressure or pulmonary function.
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Affiliation(s)
- Conor P Kerley
- a Respiratory and Sleep Diagnostics Department , Connolly Hospital , Dublin , Ireland.,b School of Biological Sciences , Dublin Institute of Technology , Dublin , Ireland
| | - Philip E James
- c School of Health Sciences , Cardiff Metropolitan University , Cardiff, UK
| | - Aisling McGowan
- a Respiratory and Sleep Diagnostics Department , Connolly Hospital , Dublin , Ireland
| | - John Faul
- a Respiratory and Sleep Diagnostics Department , Connolly Hospital , Dublin , Ireland
| | - Liam Cormican
- a Respiratory and Sleep Diagnostics Department , Connolly Hospital , Dublin , Ireland
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The Effect of a Dietary Nitrate Supplementation in the Form of a Single Shot of Beetroot Juice on Static and Dynamic Apnea Performance. Int J Sport Nutr Exerc Metab 2018; 28:497-501. [DOI: 10.1123/ijsnem.2017-0300] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Introduction: The purpose of the present study was to assess the effects of acute nitrate ()-rich beetroot juice (BRJ) supplementation on peripheral oxygen saturation (SpO2), heart rate (HR), and pulmonary gas exchange during submaximal static and dynamic apnea. Methods: Nine (six males and three females) trained apneists (age: 39.6 ± 8.2 years, stature: 170.4 ± 11.5 cm, and body mass: 72.0 ± 11.5 kg) performed three submaximal static apneas at 60%, 70%, and 80% of the participant’s current reported personal best time, followed by three submaximal (∼75% or personal best distance) dynamic apneas following the consumption of either a 70-ml concentrated BRJ (7.7 mmol ) or a -depleted placebo (PLA; 0.1 mmol ) in double-blind randomized manner. HR and SpO2 were measured via fingertip pulse oximetry at the nadir, and online gas analysis was used to assess pulmonary oxygen uptake () during recovery following breath-holds. Results: There were no differences (p < .05) among conditions for HR (PLA = 59 ± 11 bpm and BRJ = 61 ± 12 bpm), SpO2 (PLA = 83% ± 14% and BRJ = 84% ±9%), or (PLA = 1.00 ± 0.22 L/min and BRJ = 0.97 ± 0.27 L/min). Conclusion: The consumption of 7.7 mmol of beetroot juice supplementation prior to a series of submaximal static and dynamic apneas did not induce a significant change in SpO2, HR, and when compared with placebo. Therefore, there is no apparent physiological response that may benefit free divers as a result of the supplementation.
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