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Fenuta AM, Drouin PJ, Kohoko ZIN, Lynn MJT, Tschakovsky ME. Influence of acute dietary nitrate supplementation on oxygen delivery/consumption and limit of tolerance during progressive forearm exercise in men: a randomized crossover trial. Appl Physiol Nutr Metab 2024; 49:635-648. [PMID: 38190654 DOI: 10.1139/apnm-2023-0236] [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] [Indexed: 01/10/2024]
Abstract
Beetroot juice (BRJ) supplementation increases nitric oxide bioavailability with hypoxia and acidosis, characteristics of high-intensity exercise. We investigated whether BRJ improved forearm oxygen delivery:demand matching in an intensity-dependent manner. Healthy men (21 ± 2.5 years) participated in a randomized crossover trial between October 2017 and May 2018 (Queen's University, Kingston, ON, Canada). Participants completed a forearm incremental exercise test to limit of tolerance (IET-LOT) 2.5 h post placebo (PL) versus BRJ (2 completed PL/BRJ vs. 9 completed BRJ/PL) within a 2-week period. Data are presented as mean ± standard deviation. There was a significant main effect of drink (PL < BRJ; P = 0.042, ηp2 = 0.385) and drink × intensity interaction for arteriovenous oxygen difference (PL < BRJ; P = 0.03; ηp2= 0.197; 20%-50% and 90% LOT). BRJ did not influence oxygen delivery (P = 0.893, ηp2 = 0.002), forearm blood flow (P = 0.589, ηp2 = 0.03) (forearm vascular conductance (P = 0.262, ηp2 = 0.124), mean arterial pressure (P = 0.254,ηp2 = 0.128)), oxygen consumption (P = 0.194, ηp2 = 0.179) or LOT (P = 0.432, d = 0.247). In healthy men, BRJ did not improve forearm oxygen delivery (vasodilatory or pressor response) during IET-LOT. Increased arteriovenous oxygen difference at submaximal intensities did not significantly influence oxygen consumption or performance across the entire range of forearm exercise intensities. This study adds to the growing body of evidence that BRJ does not influence small muscle mass blood flow in humans regardless of exercise intensity.
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Affiliation(s)
- Alyssa M Fenuta
- School of Kinesiology and Health Studies, Queen's University, Kingston, ON, Canada
| | - Patrick J Drouin
- School of Kinesiology and Health Studies, Queen's University, Kingston, ON, Canada
| | - Zach I N Kohoko
- School of Kinesiology and Health Studies, Queen's University, Kingston, ON, Canada
| | - Mytchel J T Lynn
- School of Kinesiology and Health Studies, Queen's University, Kingston, ON, Canada
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Grosicki GJ, Flatt AA, Cross BL, Vondrasek JD, Blumenburg WT, Lincoln ZR, Chall A, Bryan A, Patel RP, Ricart K, Linder BA, Sanchez SO, Watso JC, Robinson AT. Acute beetroot juice reduces blood pressure in young Black and White males but not females. Redox Biol 2023; 63:102718. [PMID: 37120928 PMCID: PMC10172749 DOI: 10.1016/j.redox.2023.102718] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 04/08/2023] [Accepted: 04/24/2023] [Indexed: 05/02/2023] Open
Abstract
A complex interplay of social, lifestyle, and physiological factors contribute to Black Americans having the highest blood pressure (BP) in America. One potential contributor to Black adult's higher BP may be reduced nitric oxide (NO) bioavailability. Therefore, we sought to determine whether augmenting NO bioavailability with acute beetroot juice (BRJ) supplementation would reduce resting BP and cardiovascular reactivity in Black and White adults, but to a greater extent in Black adults. A total of 18 Black and 20 White (∼equal split by biological sex) young adults completed this randomized, placebo-controlled (nitrate (NO3-)-depleted BRJ), crossover design study. We measured heart rate, brachial and central BP, and arterial stiffness (via pulse wave velocity) at rest, during handgrip exercise, and during post-exercise circulatory occlusion. Compared with White adults, Black adults exhibited higher pre-supplementation resting brachial and central BP (Ps ≤0.035; e.g., brachial systolic BP: 116(11) vs. 121(7) mmHg, P = 0.023). Compared with placebo, BRJ (∼12.8 mmol NO3-) reduced resting brachial systolic BP similarly in Black (Δ-4±10 mmHg) and White (Δ-4±7 mmHg) adults (P = 0.029). However, BRJ supplementation reduced BP in males (Ps ≤ 0.020) but not females (Ps ≥ 0.299). Irrespective of race or sex, increases in plasma NO3- were associated with reduced brachial systolic BP (ρ = -0.237, P = 0.042). No other treatment effects were observed for BP or arterial stiffness at rest or during physical stress (i.e., reactivity); Ps ≥ 0.075. Despite young Black adults having higher resting BP, acute BRJ supplementation reduced systolic BP in young Black and White adults by a similar magnitude, an effect that was driven by males.
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Affiliation(s)
- Gregory J. Grosicki
- Biodynamics and Human Performance Center, Georgia Southern University, Armstrong Campus, Savannah, GA, USA
| | - Andrew A. Flatt
- Biodynamics and Human Performance Center, Georgia Southern University, Armstrong Campus, Savannah, GA, USA
| | - Brett L. Cross
- Biodynamics and Human Performance Center, Georgia Southern University, Armstrong Campus, Savannah, GA, USA
| | - Joseph D. Vondrasek
- Biodynamics and Human Performance Center, Georgia Southern University, Armstrong Campus, Savannah, GA, USA
| | - Wesley T. Blumenburg
- Biodynamics and Human Performance Center, Georgia Southern University, Armstrong Campus, Savannah, GA, USA
| | - Zoe R. Lincoln
- Biodynamics and Human Performance Center, Georgia Southern University, Armstrong Campus, Savannah, GA, USA
| | - Amy Chall
- Department of Diagnostic and Therapeutic Services, Georgia Southern University, Armstrong Campus, Savannah, GA, USA
| | - Anna Bryan
- Department of Diagnostic and Therapeutic Services, Georgia Southern University, Armstrong Campus, Savannah, GA, USA
| | - Rakesh P. Patel
- Department for Pathology and Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Karina Ricart
- Department for Pathology and Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Braxton A. Linder
- Neurovascular Physiology Laboratory, Auburn University, Auburn, AL, USA
| | - Sofia O. Sanchez
- Neurovascular Physiology Laboratory, Auburn University, Auburn, AL, USA
| | - Joseph C. Watso
- Cardiovascular and Applied Physiology Laboratory, Florida State University, Tallahassee, FL, USA
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Worley ML, Reed EL, Chapman CL, Kueck P, Seymour L, Fitts T, Zazulak H, Schlader ZJ, Johnson BD. Acute beetroot juice consumption does not alter cerebral autoregulation or cardiovagal baroreflex sensitivity during lower-body negative pressure in healthy adults. Front Hum Neurosci 2023; 17:1115355. [PMID: 36742355 PMCID: PMC9892911 DOI: 10.3389/fnhum.2023.1115355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Accepted: 01/06/2023] [Indexed: 01/20/2023] Open
Abstract
Introduction Beetroot juice (BRJ) improves peripheral endothelial function and vascular compliance, likely due to increased nitric oxide bioavailability. It is unknown if BRJ alters cerebrovascular function and cardiovagal baroreflex control in healthy individuals. Purpose We tested the hypotheses that BRJ consumption improves cerebral autoregulation (CA) and cardiovagal baroreflex sensitivity (cBRS) during lower-body negative pressure (LBNP). Methods Thirteen healthy adults (age: 26 ± 4 years; 5 women) performed oscillatory (O-LBNP) and static LBNP (S-LBNP) before (PRE) and 3 h after consuming 500 mL of BRJ (POST). Participants inhaled 3% CO2 (21% O2, 76% N2) during a 5 min baseline and throughout LBNP to attenuate reductions in end-tidal CO2 tension (PETCO2). O-LBNP was conducted at ∼0.02 Hz for six cycles (-70 mmHg), followed by a 3-min recovery before S-LBNP (-40 mmHg) for 7 min. Beat-to-beat middle cerebral artery blood velocity (MCAv) (transcranial Doppler) and blood pressure were continuously recorded. CA was assessed using transfer function analysis to calculate coherence, gain, and phase in the very-low-frequency (VLF; 0.020-0.070 Hz) and low-frequency bands (LF; 0.07-0.20 Hz). cBRS was calculated using the sequence method. Comparisons between POST vs. PRE are reported as mean ± SD. Results During O-LBNP, coherence VLF was greater at POST (0.55 ± 0.06 vs. 0.46 ± 0.08; P < 0.01), but phase VLF (P = 0.17) and gain VLF (P = 0.69) were not different. Coherence LF and phase LF were not different, but gain LF was lower at POST (1.03 ± 0.20 vs. 1.12 ± 0.30 cm/s/mmHg; P = 0.05). During S-LBNP, CA was not different in the VLF or LF bands (all P > 0.10). Up-cBRS and Down-cBRS were not different during both LBNP protocols. Conclusion These preliminary data indicate that CA and cBRS during LBNP in healthy, young adults is largely unaffected by an acute bolus of BRJ.
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Affiliation(s)
- Morgan L. Worley
- Department of Exercise and Nutrition Sciences, School of Public Health and Health Professions, University at Buffalo, Buffalo, NY, United States
| | - Emma L. Reed
- Department of Exercise and Nutrition Sciences, School of Public Health and Health Professions, University at Buffalo, Buffalo, NY, United States
- Department of Human Physiology, Bowerman Sports Science Center, University of Oregon, Eugene, OR, United States
| | - Christopher L. Chapman
- Department of Exercise and Nutrition Sciences, School of Public Health and Health Professions, University at Buffalo, Buffalo, NY, United States
- Department of Human Physiology, Bowerman Sports Science Center, University of Oregon, Eugene, OR, United States
| | - Paul Kueck
- Department of Exercise and Nutrition Sciences, School of Public Health and Health Professions, University at Buffalo, Buffalo, NY, United States
| | - Lauren Seymour
- Department of Exercise and Nutrition Sciences, School of Public Health and Health Professions, University at Buffalo, Buffalo, NY, United States
| | - Triniti Fitts
- Department of Exercise and Nutrition Sciences, School of Public Health and Health Professions, University at Buffalo, Buffalo, NY, United States
| | - Hannah Zazulak
- Department of Exercise and Nutrition Sciences, School of Public Health and Health Professions, University at Buffalo, Buffalo, NY, United States
| | - Zachary J. Schlader
- Department of Exercise and Nutrition Sciences, School of Public Health and Health Professions, University at Buffalo, Buffalo, NY, United States
- Department of Kinesiology, School of Public Health, Indiana University Bloomington, Bloomington, IN, United States
| | - Blair D. Johnson
- Department of Exercise and Nutrition Sciences, School of Public Health and Health Professions, University at Buffalo, Buffalo, NY, United States
- Department of Kinesiology, School of Public Health, Indiana University Bloomington, Bloomington, IN, United States
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Bordonie NC, Saunders MJ, de Zevallos JO, Kurti SP, Luden ND, Crance JH, Baur DA. Dietary nitrate supplementation enhances heavy load carriage performance in military cadets. Eur J Appl Physiol 2023; 123:91-102. [PMID: 36175576 DOI: 10.1007/s00421-022-05056-5] [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: 08/19/2022] [Accepted: 09/20/2022] [Indexed: 01/07/2023]
Abstract
PURPOSE To determine the effects of dietary nitrate (NO3-) supplementation on physiological responses, cognitive function, and performance during heavy load carriage in military cadets. METHODS Ten healthy males (81.0 ± 6.5 kg; 180.0 ± 4.5 cm; 56.2 ± 3.7 ml·kg·min-1 VO2max) consumed 140 mL·d-1 of beetroot juice (BRJ; 12.8 mmol NO3-) or placebo (PL) for six d preceding an exercise trial, which consisted of 45 min of load carriage (55% body mass) at 4.83 km·h-1 and 1.5% grade, followed by a 1.6-km time-trial (TT) at 4% grade. Gas exchange, heart rate, and perceptual responses were assessed during constant-load exercise and the TT. Cognitive function was assessed immediately prior to, during, and post-exercise via the psychomotor vigilance test (PVT). RESULTS Post-TT HR (188 ± 7.1 vs. 185 ± 7.4; d = 0.40; p = 0.03), mean tidal volume (2.15 ± 0.27 vs. 2.04 ± 0.23; p = 0.02; d = 0.47), and performance (770.9 ± 78.2 s vs. 809.8 ± 61.4 s; p = 0.03; d = 0.63) were increased during the TT with BRJ versus PL. There were no effects of BRJ on constant-load gas exchange or perceptual responses, and cognitive function was unchanged at all time points. CONCLUSION BRJ supplementation improves heavy load carriage performance in military cadets possibly as a result of attenuated respiratory muscle fatigue, rather than enhanced exercise economy.
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Affiliation(s)
- Nicholas C Bordonie
- Department of Kinesiology, James Madison University, Harrisonburg, VA, 22807, USA
| | - Michael J Saunders
- Department of Kinesiology, James Madison University, Harrisonburg, VA, 22807, USA
| | - Joaquin Ortiz de Zevallos
- Department of Kinesiology, School of Health and Human Development, University of Virginia, Charlottesville, VA, 22904, USA
| | - Stephanie P Kurti
- Department of Kinesiology, James Madison University, Harrisonburg, VA, 22807, USA
| | - Nicholas D Luden
- Department of Kinesiology, James Madison University, Harrisonburg, VA, 22807, USA
| | - Jenny H Crance
- Infirmary, Virginia Military Institute, Lexington, VA, 24450, USA
| | - Daniel A Baur
- Department of Human Performance and Wellness, Virginia Military Institute, 208 Cormack Hall, Lexington, VA, 24450, USA.
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Oue A, Iimura Y, Shinagawa A, Miyakoshi Y, Ota M. Effect of Acute Dietary Nitrate Supplementation on the Venous Vascular Response to Static Exercise in Healthy Young Adults. Nutrients 2022; 14:nu14214464. [PMID: 36364727 PMCID: PMC9659063 DOI: 10.3390/nu14214464] [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: 10/10/2022] [Revised: 10/21/2022] [Accepted: 10/21/2022] [Indexed: 11/16/2022] Open
Abstract
The purpose of this study was to test the hypothesis that acute intake of inorganic nitrate (NO3−) via supplementation would attenuate the venoconstriction and pressor response to exercise. Sixteen healthy young adults were assigned in a randomized crossover design to receive beetroot juice (BRJ) or an NO3−-depleted control beverage (prune juice: CON). Two hours after consuming the allocated beverage, participants rested in the supine position. Following the baseline period of 4 min, static handgrip exercise of the left hand was performed at 30% of the maximal voluntary contraction for 2 min. Mean arterial pressure (MAP) and heart rate (HR) were measured. Changes in venous volume in the right forearm and right calf were also measured using venous occlusion plethysmography while cuffs on the upper arm and thigh were inflated constantly to 30−40 mmHg. The plasma NO3− concentration was elevated with BRJ intake (p < 0.05). Exercise increased MAP and HR and decreased venous volume in the forearm and calf, but there were no differences between CON and BRJ. Thus, these findings suggest that acute BRJ intake does not alter the sympathetic venoconstriction in the non-exercising limbs and MAP response to exercise in healthy young adults, despite the enhanced activity of nitric oxide.
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Affiliation(s)
- Anna Oue
- Faculty of Food and Nutritional Sciences, Toyo University, Gunma 374-0193, Japan
- Correspondence: ; Tel.: +81-276-82-9145; Fax: +81-276-82-9033
| | - Yasuhiro Iimura
- Graduate School of Food and Nutritional Sciences, Toyo University, Gunma 374-0193, Japan
| | - Akiho Shinagawa
- Graduate School of Food and Nutritional Sciences, Toyo University, Gunma 374-0193, Japan
| | - Yuichi Miyakoshi
- Faculty of Food and Nutritional Sciences, Toyo University, Gunma 374-0193, Japan
| | - Masako Ota
- Faculty of Food and Nutritional Sciences, Toyo University, Gunma 374-0193, Japan
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Broxterman RM, La Salle DT, Zhao J, Reese VR, Kwon OS, Richardson RS, Trinity JD. Dietary Nitrate Supplementation and Small Muscle Mass Exercise Hemodynamics in Patients with Essential Hypertension. J Appl Physiol (1985) 2022; 133:506-516. [PMID: 35834624 PMCID: PMC9377785 DOI: 10.1152/japplphysiol.00218.2022] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Exaggerated blood pressure and diminished limb hemodynamics during exercise in patients with hypertension often are not resolved by antihypertensive medications. We hypothesized that, independent of antihypertensive medication status, dietary nitrate supplementation would increase limb blood flow, decrease mean arterial pressure (MAP), and increase limb vascular conductance during exercise in patients with hypertension. Patients with hypertension either abstained from (n=14, Off-Meds) or continued (n=12, On-Meds) antihypertensive medications. Within each group, patients consumed (cross-over design) nitrate-rich or nitrate-depleted (placebo) beetroot juice for 3-days before performing handgrip (HG) and knee-extensor exercise (KE). Blood flow and MAP were measured using Doppler ultrasound and an automated monitor, respectively. Dietary nitrate increased plasma-[nitrite] Off-Meds and On-Meds. There were no significant effects of dietary nitrate on blood flow, MAP, or vascular conductance during HG in Off-Meds or On-Meds. For KE, dietary nitrate decreased MAP (mean±SD across all three exercise intensities, 118±14 vs. 122±14 mmHg, p=0.024) and increased vascular conductance (26.2±6.1 vs. 24.7±7.0 ml/min/mmHg, p=0.024), but did not affect blood flow for Off-Meds, with no effects On-Meds. Dietary nitrate-induced changes in blood flow (r=-0.67, p<0.001), MAP (r=-0.43, p=0.009), and vascular conductance (r=-0.64, p<0.001) during KE, but only vascular conductance (r=-0.35, p=0.039) during HG, were significantly related to the magnitude of placebo values, with no differentiation between groups. Thus, the effects of dietary nitrate on limb hemodynamics and MAP during exercise in patients with hypertension are dependent on the values at baseline, independent of antihypertensive medication status, and dependent on whether exercise was performed by the forearm or quadriceps.
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Affiliation(s)
- Ryan M Broxterman
- Geriatric Research, Education, and Clinical Center, Salt Lake City VAMC, Salt Lake City, UT, United States.,Department of Internal Medicine, University of Utah, Salt Lake City, Utah, United States.,Center on Aging, University of Utah, Salt Lake City, UT, United States
| | - D Taylor La Salle
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, United States
| | - Jia Zhao
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah, United States
| | - Van R Reese
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah, United States
| | - Oh Sung Kwon
- Department of Kinesiology, University of Connecticut, Storrs, CT, United States.,Department of Orthopedic Surgery and Center of Aging, University of Connecticut School of Medicine, Farmington, CT, United States
| | - Russell S Richardson
- Geriatric Research, Education, and Clinical Center, Salt Lake City VAMC, Salt Lake City, UT, United States.,Department of Internal Medicine, University of Utah, Salt Lake City, Utah, United States.,Center on Aging, University of Utah, Salt Lake City, UT, United States.,Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, United States
| | - Joel D Trinity
- Geriatric Research, Education, and Clinical Center, Salt Lake City VAMC, Salt Lake City, UT, United States.,Department of Internal Medicine, University of Utah, Salt Lake City, Utah, United States.,Center on Aging, University of Utah, Salt Lake City, UT, United States.,Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, United States
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Plant-Based Foods and Vascular Function: A Systematic Review of Dietary Intervention Trials in Older Subjects and Hypothesized Mechanisms of Action. Nutrients 2022; 14:nu14132615. [PMID: 35807796 PMCID: PMC9268664 DOI: 10.3390/nu14132615] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 06/20/2022] [Accepted: 06/21/2022] [Indexed: 02/04/2023] Open
Abstract
Cardiovascular diseases, still the leading cause of mortality in the world, are closely related to vascular function. Older subjects are more susceptible to endothelial dysfunction and therefore it is important to define possible preventive or support strategies, such as consumption of foods with health-promoting effects. This systematic review aims to summarize the currently available evidence on acute or chronic trials testing the effect of selected plant-based foods on vascular function parameters in older subjects, and consider plausible mechanisms that may support the main findings. A total of 15 trials were included and analyzed, testing the effects of beetroot, plum, blueberry, and vegetable oils. We found some interesting results regarding markers of vascular reactivity, in particular for beetroot, while no effects were found for markers of arterial stiffness. The amelioration of vascular function seems to be more related to the restoration of a condition of nitric oxide impairment, exacerbated by diseases or hypoxic condition, rather than the enhancement of a physiological situation, as indicated by the limited effects on healthy older subjects or in control groups with young subjects. However, the overall set of selected studies is, in any case, rather limited and heterogeneous in terms of characteristics of the studies, indicating the need for additional high-quality intervention trials to better clarify the role of vegetable foods in restoring and/or improving vascular function in order to better elucidate the mechanisms through which these foods may exert their vascular health benefits in older subjects.
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Proctor DN, Neely KA, Mookerjee S, Tucker J, Somani YB, Flanagan M, Kim-Shapiro DB, Basu S, Muller MD, Jin-Kwang Kim D. Inorganic nitrate supplementation and blood flow restricted exercise tolerance in post-menopausal women. Nitric Oxide 2022; 122-123:26-34. [PMID: 35240317 PMCID: PMC9062890 DOI: 10.1016/j.niox.2022.02.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 02/12/2022] [Accepted: 02/25/2022] [Indexed: 11/17/2022]
Abstract
Exercise tolerance appears to benefit most from dietary nitrate (NO3-) supplementation when muscle oxygen (O2) availability is low. Using a double-blind, randomized cross-over design, we tested the hypothesis that acute NO3- supplementation would improve blood flow restricted exercise duration in post-menopausal women, a population with reduced endogenous nitric oxide bioavailability. Thirteen women (57-76 yr) performed rhythmic isometric handgrip contractions (10% MVC, 30 per min) during progressive forearm blood flow restriction (upper arm cuff gradually inflated 20 mmHg each min) on three study visits, with 7-10 days between visits. Approximately one week following the first (familiarization) visit, participants consumed 140 ml of NO3- concentrated (9.7 mmol, 0.6 gm NO3-) or NO3-depleted beetroot juice (placebo) on separate days (≥7 days apart), with handgrip exercise beginning 100 min post-consumption. Handgrip force recordings were analyzed to determine if NO3- supplementation enhanced force development as blood flow restriction progressed. Nitrate supplementation increased plasma NO3- (16.2-fold) and NO2- (4.2-fold) and time to volitional fatigue (61.8 ± 56.5 s longer duration vs. placebo visit; p = 0.03). Nitrate supplementation increased the rate of force development as forearm muscle ischemia progressed (p = 0.023 between 50 and 75% of time to fatigue) with non-significant effects thereafter (p = 0.052). No effects of nitrate supplementation were observed for mean duration of contraction or relaxation rates (all p > 0.150). These results suggest that acute NO3- supplementation prolongs time-to-fatigue and speeds grip force development during progressive forearm muscle ischemia in postmenopausal women.
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Affiliation(s)
- David N Proctor
- Penn State University, University Park, PA, USA; Penn State College of Medicine, Hershey, PA, USA.
| | | | | | | | | | - Michael Flanagan
- Penn State College of Medicine, Hershey, PA, USA; Penn State Health Family and Community Medicine, University Park, PA, USA
| | | | - Swati Basu
- Wake Forest University, Winston-Salem, NC, USA
| | - Matthew D Muller
- University Hospitals Cleveland Medical Center, Cleveland, OH, USA
| | - Danielle Jin-Kwang Kim
- Penn State University, University Park, PA, USA; Penn State College of Medicine, Hershey, PA, USA
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9
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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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10
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Bock JM, Ueda K, Feider AJ, Hanada S, Casey DP. Combined inorganic nitrate/nitrite supplementation blunts α-mediated vasoconstriction during exercise in patients with type 2 diabetes. Nitric Oxide 2021; 118:17-25. [PMID: 34718145 DOI: 10.1016/j.niox.2021.10.006] [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: 08/25/2021] [Revised: 10/21/2021] [Accepted: 10/25/2021] [Indexed: 11/28/2022]
Abstract
AIMS Patients with type 2 diabetes mellitus (T2DM) have reduced vasodilatory responses during exercise partially attributable to low nitric oxide (NO) levels. Low NO contributes to greater α-adrenergic mediated vasoconstriction in contracting skeletal muscle. We hypothesized boosting NO bioavailability via 8wks of active beetroot juice (BRA, 4.03 mmol nitrate, 0.29 mmol nitrite, n = 19) improves hyperemia, via reduced α-mediated vasoconstriction, during handgrip exercise relative to nitrate/nitrite-depleted beetroot juice (BRP, n = 18) in patients with T2DM. METHODS Forearm blood flow (FBF) and vascular conductance (FVC) were calculated at rest and during handgrip exercise (20%max, 20contractions·min-1). Phenylephrine (α1-agonist) and dexmedetomidine (α2-agonist) were infused intra-arterially during independent trials to determine the influence of α-mediated vasoconstriction on exercise hyperemia. Vasoconstriction was quantified as the percent-reduction in FVC during α-agonist infusion, relative to pre-infusion, as well as the absolute change in %FVC during exercise relative to the respective rest trial (magnitude of sympatholysis). RESULTS ΔFBF (156 ± 69 to 175 ± 73 ml min-1) and ΔFVC (130 ± 54 to 156 ± 63 ml min-1·100 mmHg-1, both P < 0.05) during exercise were augmented following BRA, but not BRP (P = 0.96 and 0.51). Phenylephrine-induced vasoconstriction during exercise was blunted following BRA (-17.1 ± 5.9 to -12.6 ± 3.1%, P < 0.01), but not BRP (P = 0.58) supplementation; the magnitude of sympatholysis was unchanged by either (beverage-by-time P = 0.15). BRA supplementation reduced dexmedetomidine-induced vasoconstriction during exercise (-23.3 ± 6.7 to -19.7 ± 5.2%) and improved the corresponding magnitude of sympatholysis (25.3 ± 11.4 to 34.4 ± 15.5%, both P < 0.05). CONCLUSIONS BRA supplementation improves the hyperemic and vasodilatory responses to exercise in patients with T2DM which appears to be attributable to reduced α-adrenergic mediated vasoconstriction in contracting skeletal muscle.
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Affiliation(s)
- Joshua M Bock
- Department of Physical Therapy and Rehabilitation Science, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Kenichi Ueda
- Department of Anesthesia, Carver College of Medicine, University of Iowa, 200 Hawkins Dr, Iowa City, IA, USA
| | - Andrew J Feider
- Department of Anesthesia, Carver College of Medicine, University of Iowa, 200 Hawkins Dr, Iowa City, IA, USA
| | - Satoshi Hanada
- Department of Anesthesia, Carver College of Medicine, University of Iowa, 200 Hawkins Dr, Iowa City, IA, USA
| | - Darren P Casey
- Department of Physical Therapy and Rehabilitation Science, Carver College of Medicine, University of Iowa, Iowa City, IA, USA; Abboud Cardiovascular Research Center, University of Iowa, 285 Newton Rd, Iowa City, IA, USA; Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, IA, 169 Newton Rd, IA, USA.
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11
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Moreira LDSG, Fanton S, Cardozo L, Borges NA, Combet E, Shiels PG, Stenvinkel P, Mafra D. Pink pressure: beetroot (Beta vulgaris rubra) as a possible novel medical therapy for chronic kidney disease. Nutr Rev 2021; 80:1041-1061. [PMID: 34613396 DOI: 10.1093/nutrit/nuab074] [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] [Indexed: 12/15/2022] Open
Abstract
Chronic kidney disease (CKD) manifests with systemic inflammation, oxidative stress, and gut dysbiosis, resulting in metabolic disorders and elevated rates of cardiovascular disease-associated death. These all correlate with a high economic cost to healthcare systems. Growing evidence indicates that diet is an indispensable ally in the prevention and management of CKD and its complications. In this context, the root vegetable beetroot (Beta vulgaris rubra) deserves special attention because it is a source of several bioactive compounds, such as nitrate, betaine, and betalain, and has shown beneficial effects in CKD, including reduction of blood pressure, anti-inflammatory effects, and antioxidant actions by scavenging radical oxidative species, as observed in preclinical studies. Beetroot consumption as a possible therapeutic strategy to improve the clinical treatment of patients with CKD and future directions for clinical studies are addressed in this narrative review.
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Affiliation(s)
- Laís de Souza Gouveia Moreira
- L.d.S.G. Moreira and D. Mafra are with the Graduate Program in Medical Sciences, Fluminense Federal University, Niterói, Rio de Janiero, Brazil. S. Fanton, L. Cardozo, and D. Mafra are with the Graduate Program in Cardiovascular Sciences, Federal Fluminense University, Niterói-Rio de Janeiro, RJ, Brazil. N.A. Borges is with the Institute of Nutrition, State University of Rio de Janeiro, Rio de Janeiro, Brazil. E. Combet is with the School of Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom. P.G. Shiels is with the Wolfson Wohl Translational Research Centre, Institute of Cancer Sciences, University of Glasgow, Glasgow, United Kingdom. P. Stenvinkel is with the Department of Renal Medicine, Karolinska University Hospital, Stockholm, Sweden
| | - Susane Fanton
- L.d.S.G. Moreira and D. Mafra are with the Graduate Program in Medical Sciences, Fluminense Federal University, Niterói, Rio de Janiero, Brazil. S. Fanton, L. Cardozo, and D. Mafra are with the Graduate Program in Cardiovascular Sciences, Federal Fluminense University, Niterói-Rio de Janeiro, RJ, Brazil. N.A. Borges is with the Institute of Nutrition, State University of Rio de Janeiro, Rio de Janeiro, Brazil. E. Combet is with the School of Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom. P.G. Shiels is with the Wolfson Wohl Translational Research Centre, Institute of Cancer Sciences, University of Glasgow, Glasgow, United Kingdom. P. Stenvinkel is with the Department of Renal Medicine, Karolinska University Hospital, Stockholm, Sweden
| | - Ludmila Cardozo
- L.d.S.G. Moreira and D. Mafra are with the Graduate Program in Medical Sciences, Fluminense Federal University, Niterói, Rio de Janiero, Brazil. S. Fanton, L. Cardozo, and D. Mafra are with the Graduate Program in Cardiovascular Sciences, Federal Fluminense University, Niterói-Rio de Janeiro, RJ, Brazil. N.A. Borges is with the Institute of Nutrition, State University of Rio de Janeiro, Rio de Janeiro, Brazil. E. Combet is with the School of Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom. P.G. Shiels is with the Wolfson Wohl Translational Research Centre, Institute of Cancer Sciences, University of Glasgow, Glasgow, United Kingdom. P. Stenvinkel is with the Department of Renal Medicine, Karolinska University Hospital, Stockholm, Sweden
| | - Natalia A Borges
- L.d.S.G. Moreira and D. Mafra are with the Graduate Program in Medical Sciences, Fluminense Federal University, Niterói, Rio de Janiero, Brazil. S. Fanton, L. Cardozo, and D. Mafra are with the Graduate Program in Cardiovascular Sciences, Federal Fluminense University, Niterói-Rio de Janeiro, RJ, Brazil. N.A. Borges is with the Institute of Nutrition, State University of Rio de Janeiro, Rio de Janeiro, Brazil. E. Combet is with the School of Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom. P.G. Shiels is with the Wolfson Wohl Translational Research Centre, Institute of Cancer Sciences, University of Glasgow, Glasgow, United Kingdom. P. Stenvinkel is with the Department of Renal Medicine, Karolinska University Hospital, Stockholm, Sweden
| | - Emilie Combet
- L.d.S.G. Moreira and D. Mafra are with the Graduate Program in Medical Sciences, Fluminense Federal University, Niterói, Rio de Janiero, Brazil. S. Fanton, L. Cardozo, and D. Mafra are with the Graduate Program in Cardiovascular Sciences, Federal Fluminense University, Niterói-Rio de Janeiro, RJ, Brazil. N.A. Borges is with the Institute of Nutrition, State University of Rio de Janeiro, Rio de Janeiro, Brazil. E. Combet is with the School of Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom. P.G. Shiels is with the Wolfson Wohl Translational Research Centre, Institute of Cancer Sciences, University of Glasgow, Glasgow, United Kingdom. P. Stenvinkel is with the Department of Renal Medicine, Karolinska University Hospital, Stockholm, Sweden
| | - Paul G Shiels
- L.d.S.G. Moreira and D. Mafra are with the Graduate Program in Medical Sciences, Fluminense Federal University, Niterói, Rio de Janiero, Brazil. S. Fanton, L. Cardozo, and D. Mafra are with the Graduate Program in Cardiovascular Sciences, Federal Fluminense University, Niterói-Rio de Janeiro, RJ, Brazil. N.A. Borges is with the Institute of Nutrition, State University of Rio de Janeiro, Rio de Janeiro, Brazil. E. Combet is with the School of Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom. P.G. Shiels is with the Wolfson Wohl Translational Research Centre, Institute of Cancer Sciences, University of Glasgow, Glasgow, United Kingdom. P. Stenvinkel is with the Department of Renal Medicine, Karolinska University Hospital, Stockholm, Sweden
| | - Peter Stenvinkel
- L.d.S.G. Moreira and D. Mafra are with the Graduate Program in Medical Sciences, Fluminense Federal University, Niterói, Rio de Janiero, Brazil. S. Fanton, L. Cardozo, and D. Mafra are with the Graduate Program in Cardiovascular Sciences, Federal Fluminense University, Niterói-Rio de Janeiro, RJ, Brazil. N.A. Borges is with the Institute of Nutrition, State University of Rio de Janeiro, Rio de Janeiro, Brazil. E. Combet is with the School of Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom. P.G. Shiels is with the Wolfson Wohl Translational Research Centre, Institute of Cancer Sciences, University of Glasgow, Glasgow, United Kingdom. P. Stenvinkel is with the Department of Renal Medicine, Karolinska University Hospital, Stockholm, Sweden
| | - Denise Mafra
- L.d.S.G. Moreira and D. Mafra are with the Graduate Program in Medical Sciences, Fluminense Federal University, Niterói, Rio de Janiero, Brazil. S. Fanton, L. Cardozo, and D. Mafra are with the Graduate Program in Cardiovascular Sciences, Federal Fluminense University, Niterói-Rio de Janeiro, RJ, Brazil. N.A. Borges is with the Institute of Nutrition, State University of Rio de Janeiro, Rio de Janeiro, Brazil. E. Combet is with the School of Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom. P.G. Shiels is with the Wolfson Wohl Translational Research Centre, Institute of Cancer Sciences, University of Glasgow, Glasgow, United Kingdom. P. Stenvinkel is with the Department of Renal Medicine, Karolinska University Hospital, Stockholm, Sweden
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12
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Nyberg M, Christensen PM, Blackwell JR, Hostrup M, Jones AM, Bangsbo J. Nitrate-rich beetroot juice ingestion reduces skeletal muscle O 2 uptake and blood flow during exercise in sedentary men. J Physiol 2021; 599:5203-5214. [PMID: 34587650 DOI: 10.1113/jp281995] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Accepted: 09/22/2021] [Indexed: 12/21/2022] Open
Abstract
Dietary nitrate supplementation has been shown to reduce pulmonary O2 uptake during submaximal exercise and enhance exercise performance. However, the effects of nitrate supplementation on local metabolic and haemodynamic regulation in contracting human skeletal muscle remain unclear. To address this, eight healthy young male sedentary subjects were assigned in a randomized, double-blind, crossover design to receive nitrate-rich beetroot juice (NO3, 9 mmol) and placebo (PLA) 2.5 h prior to the completion of a double-step knee-extensor exercise protocol that included a transition from unloaded to moderate-intensity exercise (MOD) followed immediately by a transition to intense exercise (HIGH). Compared with PLA, NO3 increased plasma levels of nitrate and nitrite. During MOD, leg V ̇ O 2 and leg blood flow (LBF) were reduced to a similar extent (∼9%-15%) in NO3. During HIGH, leg V ̇ O 2 was reduced by ∼6%-10% and LBF by ∼5%-9% (did not reach significance) in NO3. Leg V ̇ O 2 kinetics was markedly faster in the transition from passive to MOD compared with the transition from MOD to HIGH both in NO3 and PLA with no difference between PLA and NO3. In NO3, a reduction in nitrate and nitrite concentration was detected between arterial and venous samples. No difference in the time to exhaustion was observed between conditions. In conclusion, elevation of plasma nitrate and nitrate reduces leg skeletal muscle V ̇ O 2 and blood flow during exercise. However, nitrate supplementation does not enhance muscle V ̇ O 2 kinetics during exercise, nor does it improve time to exhaustion when exercising with a small muscle mass. KEY POINTS: Dietary nitrate supplementation has been shown to reduce systemic O2 uptake during exercise and improve exercise performance. The effects of nitrate supplementation on local metabolism and blood flow regulation in contracting human skeletal muscle remain unclear. By using leg exercise engaging a small muscle mass, we show that O2 uptake and blood flow are similarly reduced in contracting skeletal muscle of humans during exercise. Despite slower V ̇ O 2 kinetics in the transition from moderate to intense exercise, no effects of nitrate supplementation were observed for V ̇ O 2 kinetics and time to exhaustion. Nitrate and nitrite concentrations are reduced across the exercising leg, suggesting that these ions are extracted from the arterial blood by contracting skeletal muscle.
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Affiliation(s)
- Michael Nyberg
- Department of Nutrition, Exercise and Sports, Integrative Physiology Section, Cardiovascular Physiology, University of Copenhagen, Copenhagen, Denmark
| | - Peter M Christensen
- Department of Nutrition, Exercise and Sports, Integrative Physiology Section, Cardiovascular Physiology, University of Copenhagen, Copenhagen, Denmark.,Team Danmark (Danish Elite Sports Organization), Copenhagen, Denmark
| | - Jamie R Blackwell
- Department of Sport and Health Sciences, University of Exeter St Luke's Campus, Exeter, UK
| | - Morten Hostrup
- Department of Nutrition, Exercise and Sports, Integrative Physiology Section, Cardiovascular Physiology, University of Copenhagen, Copenhagen, Denmark
| | - Andrew M Jones
- Department of Sport and Health Sciences, University of Exeter St Luke's Campus, Exeter, UK
| | - Jens Bangsbo
- Department of Nutrition, Exercise and Sports, Integrative Physiology Section, Cardiovascular Physiology, University of Copenhagen, Copenhagen, Denmark
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13
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Gonzalez AM, Accetta MR, Spitz RW, Mangine GT, Ghigiarelli JJ, Sell KM. Red Spinach Extract Supplementation Improves Cycle Time Trial Performance in Recreationally Active Men and Women. J Strength Cond Res 2021; 35:2541-2545. [PMID: 31136549 DOI: 10.1519/jsc.0000000000003173] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Adam M Gonzalez
- Department of Health Professions, Hofstra University, Hempstead, New York; and
| | - Matthew R Accetta
- Department of Health Professions, Hofstra University, Hempstead, New York; and
| | - Robert W Spitz
- Department of Health Professions, Hofstra University, Hempstead, New York; and
| | - Gerald T Mangine
- Department of Exercise Science and Sport Management, Kennesaw State University, Kennesaw, Georgia
| | - Jamie J Ghigiarelli
- Department of Health Professions, Hofstra University, Hempstead, New York; and
| | - Katie M Sell
- Department of Health Professions, Hofstra University, Hempstead, New York; and
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14
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Lawler T, Korger J, Liu Y, Liu Z, Pak JW, Barrett N, Blodi B, Domalpally A, Johnson E, Wallace R, Mares JA. Serum and Macular Carotenoids in Relation to Retinal Vessel Caliber Fifteen Years Later, in the Second Carotenoids in Age-Related Eye Disease Study. Invest Ophthalmol Vis Sci 2021; 62:20. [PMID: 34254974 PMCID: PMC8288049 DOI: 10.1167/iovs.62.9.20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose We investigated whether dietary carotenoids lutein and zeaxanthin (L/Z) in the serum and macula were associated with central retinal arteriole and venule calibers in a follow-up ancillary study among older women in the Women's Health Initiative. Methods Among 390 women who participated in Carotenoids in Age-Related Eye Disease Study 2 (CAREDS2) (2016–2019), we investigated associations between serum L/Z at Women's Health Initiative baseline (1994–1998), and macular pigment optical density (MPOD) at CAREDS baseline (2001–2004), with central retinal vessel caliber in CAREDS2. MPOD was measured using heterochromatic flicker photometry (0.5° from the foveal center) in CAREDS baseline and CAREDS2. Vessel calibers were measured from fundus photographs (CAREDS2). We also explored associations in women with stable MPOD (±0.10 optical density units) over 15 years (n = 106), given the long-term increases in MPOD related to diet patterns and supplement use. Associations were investigated using linear modeling. Results In the full sample (n = 390), higher serum L/Z (tertile 3 vs. 1) was positively associated with arteriole caliber (mean ± SE, 145.0 ± 1.4 µm vs. 140.8 ± 1.4 µm; P = 0.05) and venule caliber (214.6 ± 2.2 µm vs. 207.5 ± 2.2 µm; P = 0.03). MPOD was also associated with wider vessel calibers (tertile 3 vs. 1), but the trend was only statistically significant for venules (144.4 ± 1.4 µm vs. 141.1 ± 1.4 µm [P = 0.12] and 213.3 ± 2.1 µm vs. 206.0 ± 2.1 µm [P = 0.02], respectively.) Most associations were strengthened in women with stable MPOD over 15 years, including between MPOD and arteriole caliber (149.8 ± 2.6 µm vs.135.8 ± 3.0 µm; P = 0.001). Conclusions Higher L/Z status in serum and retina was associated with larger central retinal vessel calibers. Prospective studies and clinical trials are needed to elucidate whether L/Z supplementation prevents vision loss through increasing blood flow.
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Affiliation(s)
- Thomas Lawler
- Department of Nutritional Sciences, College of Agricultural & Life Sciences, University of Wisconsin, Madison, Wisconsin, United States
| | - Jackson Korger
- Department of Ophthalmology and Visual Sciences, School of Medicine and Population Health, University of Wisconsin, Madison, Wisconsin, United States
| | - Yao Liu
- Department of Ophthalmology and Visual Sciences, School of Medicine and Population Health, University of Wisconsin, Madison, Wisconsin, United States
| | - Zhe Liu
- Department of Ophthalmology and Visual Sciences, School of Medicine and Population Health, University of Wisconsin, Madison, Wisconsin, United States
| | - Jeong W Pak
- Department of Ophthalmology and Visual Sciences, School of Medicine and Population Health, University of Wisconsin, Madison, Wisconsin, United States
| | - Nancy Barrett
- Department of Ophthalmology and Visual Sciences, School of Medicine and Population Health, University of Wisconsin, Madison, Wisconsin, United States
| | - Barbara Blodi
- Department of Ophthalmology and Visual Sciences, School of Medicine and Population Health, University of Wisconsin, Madison, Wisconsin, United States
| | - Amitha Domalpally
- Department of Ophthalmology and Visual Sciences, School of Medicine and Population Health, University of Wisconsin, Madison, Wisconsin, United States
| | - Elizabeth Johnson
- Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, Massachusetts, United States
| | - Robert Wallace
- Department of Epidemiology, University of Iowa College of Public Health, Iowa City, Iowa, United States
| | - Julie A Mares
- Department of Nutritional Sciences, College of Agricultural & Life Sciences, University of Wisconsin, Madison, Wisconsin, United States.,The full list of CAREDS2 Investigators and research team is listed in the Acknowledgments
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15
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Chapman CL, Schlader ZJ, Reed EL, Worley ML, Johnson BD. Acute Beetroot Juice Ingestion Does Not Alter Renal Hemodynamics during Normoxia and Mild Hypercapnia in Healthy Young Adults. Nutrients 2021; 13:nu13061986. [PMID: 34207775 PMCID: PMC8227249 DOI: 10.3390/nu13061986] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 06/03/2021] [Accepted: 06/07/2021] [Indexed: 12/24/2022] Open
Abstract
Arterial hypercapnia reduces renal perfusion. Beetroot juice (BRJ) increases nitric oxide bioavailability and may improve renal blood flow. We tested the hypothesis that acute consumption of BRJ attenuates both decreases in blood velocity and increases in vascular resistance in the renal and segmental arteries during acute hypercapnia. In fourteen healthy young adults, blood velocity and vascular resistance were measured with Doppler ultrasound in the renal and segmental arteries during five minutes of breathing a carbon dioxide gas mixture (CO2) before and three hours after consuming 500 mL of BRJ. There was no difference between pre- and post-BRJ consumption in the increase in the partial pressure of end-tidal CO2 during CO2 breathing (pre: +4 ± 1 mmHg; post: +4 ± 2 mmHg, p = 0.4281). Segmental artery blood velocity decreased during CO2 breathing in both pre- (by −1.8 ± 1.9 cm/s, p = 0.0193) and post-BRJ (by −2.1 ± 1.9 cm/s, p = 0.0079), but there were no differences between pre- and post-consumption (p = 0.7633). Segmental artery vascular resistance increased from room air baseline during CO2 at pre-BRJ consumption (by 0.4 ± 0.4 mmHg/cm/s, p = 0.0153) but not post-BRJ (p = 0.1336), with no differences between pre- and post-consumption (p = 0.7407). These findings indicate that BRJ consumption does not attenuate reductions in renal perfusion during acute mild hypercapnia in healthy young adults.
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Affiliation(s)
- Christopher L. Chapman
- Center for Research and Education in Special Environments, Department of Exercise & Nutrition Sciences, University at Buffalo, Buffalo, NY 14214, USA; (C.L.C.); (E.L.R.); (M.L.W.)
- Department of Human Physiology, University of Oregon, Eugene, OR 97403, USA
| | - Zachary J. Schlader
- Department of Kinesiology, School of Public Health, Indiana University, Bloomington, IN 47405, USA;
| | - Emma L. Reed
- Center for Research and Education in Special Environments, Department of Exercise & Nutrition Sciences, University at Buffalo, Buffalo, NY 14214, USA; (C.L.C.); (E.L.R.); (M.L.W.)
- Department of Human Physiology, University of Oregon, Eugene, OR 97403, USA
| | - Morgan L. Worley
- Center for Research and Education in Special Environments, Department of Exercise & Nutrition Sciences, University at Buffalo, Buffalo, NY 14214, USA; (C.L.C.); (E.L.R.); (M.L.W.)
- Department of Kinesiology, School of Public Health, Indiana University, Bloomington, IN 47405, USA;
| | - Blair D. Johnson
- Center for Research and Education in Special Environments, Department of Exercise & Nutrition Sciences, University at Buffalo, Buffalo, NY 14214, USA; (C.L.C.); (E.L.R.); (M.L.W.)
- Department of Kinesiology, School of Public Health, Indiana University, Bloomington, IN 47405, USA;
- Correspondence:
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16
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Diaz-Canestro C, Pentz B, Sehgal A, Montero D. Sex Differences In Cardiorespiratory Fitness Are Explained By Blood Volume And Oxygen Carrying Capacity. Cardiovasc Res 2021; 118:334-343. [PMID: 33538810 DOI: 10.1093/cvr/cvab028] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 08/26/2021] [Accepted: 01/22/2021] [Indexed: 11/13/2022] Open
Abstract
AIMS Intrinsic sex differences in fundamental blood attributes have long been hypothesized to contribute to the gap in cardiorespiratory fitness between men and women. This study experimentally assessed the role of blood volume and oxygen (O2) carrying capacity on sex differences in cardiac function and aerobic power. METHODS AND RESULTS Healthy women and men (n = 60) throughout the mature adult lifespan (42-88 yr) were matched by age and physical activity levels. Transthoracic echocardiography, central blood pressure and O2 uptake were assessed throughout incremental exercise (cycle ergometry). Main outcomes such as left ventricular end-diastolic volume (LVEDV), stroke volume (SV), cardiac output (Q), and peak O2 uptake (VO2peak), as well as blood volume (BV) were determined with established methods. Measurements were repeated in men following blood withdrawal and O2 carrying capacity reduction matching women's levels. Prior to blood normalization, BV and O2 carrying capacity were markedly reduced in women compared with men (P < 0.001). Blood normalization resulted in a precise match of BV (82.36 ± 9.83 vs. 82.34 ± 7.70 ml·kg-1, P = 0.993) and O2 carrying capacity (12.0 ± 0.6 vs. 12.0 ± 0.7 g·dl-1, P = 0.562) between women and men. Body size-adjusted cardiac filling and output (LVEDV, SV, Q) during exercise as well as VO2peak (30.8 ± 7.5 vs. 35.6 ± 8.7 ml·min-1·kg-1, P < 0.001) were lower in women compared with men prior to blood normalization. VO2peak did not differ between women and men after blood normalization (30.8 ± 7.5 vs. 29.7 ± 7.4 ml·min-1·kg-1, P = 0.551). CONCLUSIONS Sex differences in cardiorespiratory fitness are abolished when blood attributes determining O2 delivery are experimentally matched between adult women and men. TRANSLATIONAL PERSPECTIVE Low cardiorespiratory fitness is strongly associated with all-cause and cardiovascular mortality in asymptomatic adults independently of traditional risk factors, relationships seemingly enhanced in middle-aged and older women. Yet, whether the primary hematological determinants of cardiorespiratory fitness that were established in studies comprising men explain the difference between sexes remains uncertain. Importantly, blood attributes are amenable to modification and thus potentially translated into effective targets to improve or preserve cardiovascular health in the general population. The present experimental study demonstrates that blood normalization between men and women eliminate sex differences in cardiorespiratory fitness.
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Affiliation(s)
- Candela Diaz-Canestro
- Faculty of Kinesiology, University of Calgary, Canada.,Libin Cardiovascular Institute of Alberta, University of Calgary, Canada
| | - Brandon Pentz
- Faculty of Kinesiology, University of Calgary, Canada
| | - Arshia Sehgal
- Faculty of Kinesiology, University of Calgary, Canada
| | - David Montero
- Faculty of Kinesiology, University of Calgary, Canada.,Libin Cardiovascular Institute of Alberta, University of Calgary, Canada.,Cumming School of Medicine, Calgary, Canada
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17
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Casey DP, Bock JM. Inorganic nitrate supplementation attenuates conduit artery retrograde and oscillatory shear in older adults. Am J Physiol Heart Circ Physiol 2021; 320:H991-H998. [PMID: 33449848 DOI: 10.1152/ajpheart.00843.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Aging causes deleterious changes in resting conduit artery shear patterns and reduced blood flow during exercise partially attributable to reduced nitric oxide (NO). Inorganic nitrate increases circulating NO bioavailability and may, therefore, improve age-associated changes in shear rate as well as exercise hyperemia. Ten older adults (age: 67 ± 3 yr) consumed 4.03 mmol nitrate and 0.29 mmol nitrite (active) or devoid of both (placebo) daily for 4 wk in a randomized, double-blinded, crossover fashion. Brachial artery diameter (D) and blood velocity (Vmean) were measured via Doppler ultrasound at rest for the characterization of shear profile as well as during two handgrip exercise trials (4 and 8 kg) for calculation of forearm blood flow (Vmean × cross-sectional area, FBF) and conductance [FBF/mean arterial pressure, forearm vascular conductance (FVC)]. Plasma [nitrate] and [nitrite] increased following active (P < 0.05 for both) but not placebo (P = 0.68 and 0.40, respectively) supplementation. Neither mean nor antegrade shear rate changed following either supplement (beverage-by-time P = 0.14 and 0.21, respectively). Retrograde (-13.4 ± 7.0 to -9.7 ± 6.8·s-1) and oscillatory (0.20 ± 0.08 to 0.15 ± 0.09 A.U., P < 0.05 for both) shear decreased following active, but not placebo (P = 0.81 and 0.70, respectively), supplementation. The FBF response (Δ from rest) to neither 4-kg nor 8-kg trials changed following either supplement (beverage-by-time P = 0.53 and 0.11, respectively). Similarly, no changes were observed in FVC responses to 4-kg or 8-kg trials (beverage-by-time P = 0.23 and 0.07, respectively). These data indicate that inorganic nitrate supplementation improves conduit artery shear profiles, but not exercise hyperemia, in older adults.NEW & NOTEWORTHY We report for the first time, to our knowledge, that 4 wk of inorganic nitrate supplementation attenuates retrograde and oscillatory shear in the brachial artery of older adults. However, this was not associated with greater hyperemic or vasodilatory responses to exercise. In sum, these data highlight favorable changes in shear patterns with aging, which may reduce the risk of atherosclerotic cardiovascular disease.
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Affiliation(s)
- Darren P Casey
- Department of Physical Therapy and Rehabilitation Science, Carver College of Medicine, University of Iowa, Iowa City, Iowa.,Abboud Cardiovascular Research Center, Carver College of Medicine, University of Iowa, Iowa City, Iowa.,Fraternal Order of Eagles Diabetes Research Center, Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Joshua M Bock
- Department of Physical Therapy and Rehabilitation Science, Carver College of Medicine, University of Iowa, Iowa City, Iowa
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18
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Rotarius TR, Lauver JD, Thistlethwaite JR, Scheuermann BW. Muscle blood flow is independent of conduit artery diameter following prior vasodilation in males. Physiol Rep 2021; 9:e14698. [PMID: 33427413 PMCID: PMC7798049 DOI: 10.14814/phy2.14698] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 11/27/2020] [Accepted: 12/06/2020] [Indexed: 11/29/2022] Open
Abstract
At the onset of exercise in humans, muscle blood flow (MBF) increases to a new steady‐state that closely matches the metabolic demand of exercise. This increase has been attributed to “contraction‐induced vasodilation,” comprised of the skeletal muscle pump and rapid vasodilatory mechanisms. While most research in this area has focused on forearm blood flow (FBF) and vascular conductance, it is possible that separating FBF into diameter and blood velocity can provide more useful information on MBF regulation downstream of the conduit artery. Therefore, we attempted to dissociate the matching of oxygen delivery and oxygen demand by administering glyceryl tri‐nitrate (GTN) prior to handgrip exercise. Eight healthy males (29 ± 9 years) performed two trials consisting of two bouts of rhythmic handgrip exercise (30 contractions·min−1 at 5% of maximum) for 6 min, one for each control and GTN (0.4 mg sublingual) condition. Administration of GTN resulted in a 12% increase in resting brachial artery diameter that persisted throughout the duration of exercise (CON: 0.50 ± 0.01 cm; GTN: 0.56 ± 0.01 cm, p < 0.05). Resting FBF was greater following GTN administration compared to control (p < 0.05); however, differences in FBF disappeared following the onset of muscle contractions. Our results indicate that the matching of FBF to oxygen demand during exercise is not affected by prior vasodilation, so that any over‐perfusion is corrected at the onset of exercise. Additionally, our findings provide further evidence that the regulation of vascular tone within the microvasculature is independent of the conduit artery diameter.
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Affiliation(s)
- Timothy R Rotarius
- Department of Exercise Science and Athletic Training, Adrian College, Adrian, MI, USA
| | - Jakob D Lauver
- Department of Kinesiology, Coastal Carolina University, Conway, SC, USA
| | | | - Barry W Scheuermann
- School of Exercise and Rehabilitation Sciences, University of Toledo, Toledo, OH, USA
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19
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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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20
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Behrens CE, Ahmed K, Ricart K, Linder B, Fernández J, Bertrand B, Patel RP, Fisher G. Acute beetroot juice supplementation improves exercise tolerance and cycling efficiency in adults with obesity. Physiol Rep 2020; 8:e14574. [PMID: 33063953 PMCID: PMC7556310 DOI: 10.14814/phy2.14574] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 08/16/2020] [Accepted: 08/19/2020] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Exercise training improves health outcomes in individuals with obesity (IO); however, it remains challenging for IO to adhere to exercise. Thus, it is critical to identify novel strategies that improve exercise tolerance (ET) and adherence in IO. Beetroot juice (BRJ), high in inorganic dietary nitrate, consistently improves exercise performance in athletes, individuals with cardiopulmonary diseases, and nonobese lean individuals. These improvements may be explained by reduced oxygen uptake (VO2 ) during exercise, enhanced blood flow, and greater mitochondrial efficiency. To date, we are aware of no studies that have compared the effects of BRJ, sodium nitrate (NaNO3), and nitrate-depleted BRJ (PLA) for improving ET and cardiometabolic health in IO. PURPOSE Determine if BRJ improves ET, exercise efficiency (EE), and cardiometabolic health in IO and identify possible mechanisms of action. METHODS Vascular hemodynamic, submaximal- and maximal-exercise VO2 , and time to exhaustion (TTE) were assessed in 16 participants 2.5 hr following consumption of: 1) BRJ, 2) NaNO3 , 3) PLA, or 4) CON. RESULTS A significant treatment effect was observed for submaximal exercise VO2 (p = .003), and TTE (p < .001). Post hoc analyses revealed lower VO2 during submaximal exercise in BRJ compared to PLA (p = .009) NaNO3 (p = .042) and CON (0.009), equating to an average improvement of ~ 7% with BRJ. TTE was greater for BRJ compared to other treatment arms, PLA (p = .008), NaNO3 (p = .038), and CON (p=<0.001), equating to ~ 15% improvement with BRJ. No significant changes were observed for other outcomes. CONCLUSIONS Consumption of BRJ improved EE during submaximal exercise by 7%, and TTE by 15% compared to other conditions. These results suggest that BRJ may improve EE and exercise tolerance in IO.
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Affiliation(s)
- Christian E. Behrens
- Department of Nutrition SciencesThe University of Alabama at BirminghamBirminghamALUSA
| | - Khandaker Ahmed
- Department of Pathology and Center for Free Radical BiologyThe University of Alabama at BirminghamBirminghamALUSA
| | - Karina Ricart
- Department of Pathology and Center for Free Radical BiologyThe University of Alabama at BirminghamBirminghamALUSA
| | - Braxton Linder
- Department of Human StudiesThe University of Alabama at BirminghamBirminghamALUSA
| | - José Fernández
- Department of Nutrition SciencesThe University of Alabama at BirminghamBirminghamALUSA
| | - Brenda Bertrand
- Department of Nutrition SciencesThe University of Alabama at BirminghamBirminghamALUSA
| | - Rakesh P. Patel
- Department of Pathology and Center for Free Radical BiologyThe University of Alabama at BirminghamBirminghamALUSA
| | - Gordon Fisher
- Department of Human StudiesThe University of Alabama at BirminghamBirminghamALUSA
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21
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Hughes WE, Kruse NT, Ueda K, Feider AJ, Hanada S, Bock JM, Casey DP. Dietary nitrate does not acutely enhance skeletal muscle blood flow and vasodilation in the lower limbs of older adults during single-limb exercise. Eur J Appl Physiol 2020; 120:1357-1369. [DOI: 10.1007/s00421-020-04368-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 04/05/2020] [Indexed: 12/21/2022]
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22
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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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23
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Trexler ET, Keith DS, Schwartz TA, Ryan ED, Stoner L, Persky AM, Smith-Ryan AE. Effects of Citrulline Malate and Beetroot Juice Supplementation on Blood Flow, Energy Metabolism, and Performance During Maximum Effort Leg Extension Exercise. J Strength Cond Res 2019; 33:2321-2329. [DOI: 10.1519/jsc.0000000000003286] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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24
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Trexler ET, Keith DS, Lucero AA, Stoner L, Schwartz TA, Persky AM, Ryan ED, Smith-Ryan AE. Effects of Citrulline Malate and Beetroot Juice Supplementation on Energy Metabolism and Blood Flow During Submaximal Resistance Exercise. J Diet Suppl 2019; 17:698-717. [DOI: 10.1080/19390211.2019.1650866] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Eric T. Trexler
- Human Movement Science Curriculum, Department of Allied Health Sciences, University of North Carolina, Chapel Hill, NC, USA
- Applied Physiology Laboratory, Department of Exercise and Sport Science, University of North Carolina, Chapel Hill, NC, USA
| | - Dale S. Keith
- Applied Physiology Laboratory, Department of Exercise and Sport Science, University of North Carolina, Chapel Hill, NC, USA
| | - Adam A. Lucero
- School of Sport, Exercise and Nutrition, Massey University, Wellington, NZ
| | - Lee Stoner
- Human Movement Science Curriculum, Department of Allied Health Sciences, University of North Carolina, Chapel Hill, NC, USA
- Applied Physiology Laboratory, Department of Exercise and Sport Science, University of North Carolina, Chapel Hill, NC, USA
| | - Todd A. Schwartz
- Department of Biostatistics, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, USA
| | - Adam M. Persky
- Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, USA
| | - Eric D. Ryan
- Human Movement Science Curriculum, Department of Allied Health Sciences, University of North Carolina, Chapel Hill, NC, USA
- Applied Physiology Laboratory, Department of Exercise and Sport Science, University of North Carolina, Chapel Hill, NC, USA
| | - Abbie E. Smith-Ryan
- Human Movement Science Curriculum, Department of Allied Health Sciences, University of North Carolina, Chapel Hill, NC, USA
- Applied Physiology Laboratory, Department of Exercise and Sport Science, University of North Carolina, Chapel Hill, NC, USA
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25
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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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26
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de Vries CJ, DeLorey DS. Effect of acute dietary nitrate supplementation on sympathetic vasoconstriction at rest and during exercise. J Appl Physiol (1985) 2019; 127:81-88. [PMID: 31095461 DOI: 10.1152/japplphysiol.01053.2018] [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] [Indexed: 11/22/2022] Open
Abstract
Dietary nitrate ( NO3- ) supplementation has been shown to reduce resting blood pressure. However, the mechanism responsible for the reduction in blood pressure has not been identified. Dietary NO3- supplementation may increase nitric oxide (NO) bioavailability, and NO has been shown to inhibit sympathetic vasoconstriction in resting and contracting skeletal muscle. Therefore, the purpose of this study was to investigate the hypothesis that acute dietary NO3- supplementation would attenuate sympathetic vasoconstrictor responsiveness at rest and during exercise. In a double-blind randomized crossover design, 12 men (23 ± 5 yr) performed a cold-pressor test (CPT) at rest and during moderate- and heavy-intensity alternate-leg knee-extension exercise after consumption of NO3- rich beetroot juice (~12.9 mmol NO3- ) or a NO3- -depleted placebo (~0.13 mmol NO3- ). Venous blood was sampled before and 2.5 h after the consumption of beetroot juice for the measurement of total plasma nitrite/ NO3- [NOx]. Beat-by-beat blood pressure was measured by Finometer. Leg blood flow was measured at the femoral artery via Doppler ultrasound, and leg vascular conductance (LVC) was calculated. Sympathetic vasoconstrictor responsiveness was calculated as the percentage decrease in LVC in response to the CPT. Total plasma [NOx] was greater (P < 0.001) in the NO3- (285 ± 120 µM) compared with the placebo (65 ± 30 µM) condition. However, mean arterial blood pressure and plasma catecholamines were not different (P > 0.05) between NO3- and placebo conditions at rest or during moderate- and heavy-intensity exercise. Sympathetic vasoconstrictor responsiveness (Δ% LVC) was not different (P > 0.05) between NO3- and placebo conditions at rest ( NO3- : -33 ± 10%; placebo: -35 ± 11%) or during moderate ( NO3- : -18 ± 8%; placebo: -20 ± 10%)- and heavy ( NO3- : -12 ± 8%; placebo: -11 ± 9%)-intensity exercise. These data demonstrate that acute dietary NO3- supplementation does not alter sympathetic vasoconstrictor responsiveness at rest or during exercise in young healthy males. NEW & NOTEWORTHY Dietary nitrate may increase nitric oxide bioavailability, and nitric oxide has been shown to attenuate sympathetic vasoconstriction in resting and contracting skeletal muscle and enhance functional sympatholysis. However, the effect of dietary nitrate on sympathetic vasoconstrictor responsiveness is unknown. Acute dietary nitrate supplementation did not alter blood pressure or sympathetic vasoconstrictor responsiveness at rest or during exercise in young healthy males.
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Affiliation(s)
- Christopher J de Vries
- Faculty of Kinesiology, Sport, and Recreation, University of Alberta , Edmonton, Alberta , Canada
| | - Darren S DeLorey
- Faculty of Kinesiology, Sport, and Recreation, University of Alberta , Edmonton, Alberta , Canada
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27
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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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28
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Walker MA, Bailey TG, McIlvenna L, Allen JD, Green DJ, Askew CD. Acute Dietary Nitrate Supplementation Improves Flow Mediated Dilatation of the Superficial Femoral Artery in Healthy Older Males. Nutrients 2019; 11:E954. [PMID: 31035478 PMCID: PMC6566150 DOI: 10.3390/nu11050954] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 04/18/2019] [Accepted: 04/24/2019] [Indexed: 12/15/2022] Open
Abstract
Aging is often associated with reduced leg blood flow, increased arterial stiffness, and endothelial dysfunction, all of which are related to declining nitric oxide (NO) bioavailability. Flow mediated dilatation (FMD) and passive leg movement (PLM) hyperaemia are two techniques used to measure NO-dependent vascular function. We hypothesised that acute dietary nitrate (NO3-) supplementation would improve NO bioavailability, leg FMD, and PLM hyperaemia. Fifteen healthy older men (69 ± 4 years) attended two experiment sessions and consumed either 140 mL of concentrated beetroot juice (800 mg NO3-) or placebo (NO3--depleted beetroot juice) in a randomised, double blind, cross-over design study. Plasma nitrite (NO2-) and NO3-, blood pressure (BP), augmentation index (AIx75), pulse wave velocity (PWV), FMD of the superficial femoral artery, and PLM hyperaemia were measured immediately before and 2.5 h after consuming NO3- and placebo. Placebo had no effect but NO3- led to an 8.6-fold increase in plasma NO2-, which was accompanied by an increase in FMD (NO3-: +1.18 ± 0.94% vs. placebo: 0.23 ± 1.13%, p = 0.002), and a reduction in AIx75 (NO3-: -8.7 ± 11.6% vs. placebo: -4.6 ± 5.5%, p = 0.027). PLM hyperaemia, BP, and PWV were unchanged during both trials. This study showed that a dose of dietary NO3- improved NO bioavailability and enhanced endothelial function as measured by femoral artery FMD. These findings provide insight into the specific central and peripheral vascular responses to dietary NO3- supplementation in older adults.
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Affiliation(s)
- Meegan A Walker
- VasoActive Research Group, School of Health and Sport Sciences, University of the Sunshine Coast, Sippy Downs, QLD 4556, Australia.
| | - Tom G Bailey
- VasoActive Research Group, School of Health and Sport Sciences, University of the Sunshine Coast, Sippy Downs, QLD 4556, Australia.
- School of Human Movement and Nutrition Sciences, University of Queensland, St Lucia, QLD 4072, Australia.
| | - Luke McIlvenna
- Institute for Health and Sport, College of Sport and Exercise Science, Victoria University, Melbourne, VIC 3031, Australia.
| | - Jason D Allen
- Institute for Health and Sport, College of Sport and Exercise Science, Victoria University, Melbourne, VIC 3031, Australia.
- Department of Kinesiology, University of Virginia, Charlottesville, VA 22903, USA.
| | - Daniel J Green
- School of Sport Sciences, Exercise and Health, University of Western Australia, West Perth, WA 6872, Australia.
| | - Christopher D Askew
- VasoActive Research Group, School of Health and Sport Sciences, University of the Sunshine Coast, Sippy Downs, QLD 4556, Australia.
- Sunshine Coast Health Institute, Sunshine Coast Hospital and Health Service, Birtinya, QLD 4575, Australia.
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29
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Craig JC, Colburn TD, Hirai DM, Musch TI, Poole DC. Sexual dimorphism in the control of skeletal muscle interstitial Po 2 of heart failure rats: effects of dietary nitrate supplementation. J Appl Physiol (1985) 2019; 126:1184-1192. [PMID: 30844332 DOI: 10.1152/japplphysiol.01004.2018] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Sex differences in the mechanisms underlying cardiovascular pathophysiology of O2 transport in heart failure (HF) remain to be explored. In HF, nitric oxide (NO) bioavailability is reduced and contributes to deficits in O2 delivery-to-utilization matching. Females may rely more on NO for cardiovascular control and as such experience greater decrements in HF. We tested the hypotheses that moderate HF induced by myocardial infarction would attenuate the skeletal muscle interstitial Po2 response to contractions (Po2is; determined by O2 delivery-to-utilization matching) compared with healthy controls and females would express greater dysfunction than male counterparts. Furthermore, we hypothesized that 5 days of dietary nitrate supplementation (Nitrate; 1 mmol·kg-1·day-1) would raise Po2is in HF rats. Forty-two Sprague-Dawley rats were randomly assigned to healthy, HF, or HF + Nitrate groups (each n = 14; 7 female/7 male). Spinotrapezius Po2is was measured via phosphorescence quenching during electrically induced twitch contractions (180 s; 1 Hz). HF reduced resting Po2is for both sexes compared with healthy controls (P < 0.01), and females were lower than males (14 ± 1 vs. 17 ± 2 mmHg) (P < 0.05). In HF both sexes expressed reduced Po2is amplitudes following the onset of muscle contractions compared with healthy controls (female: -41 ± 7%, male: -26 ± 12%) (P < 0.01). In HF rats, Nitrate elevated resting Po2is to values not different from healthy rats and removed the sex difference. Female HF + Nitrate rats expressed greater resting Po2is and amplitudes compared with female HF (P < 0.05). In this model of moderate HF, O2 delivery-to-utilization matching in the interstitial space is diminished in a sex-specific manner and dietary nitrate supplementation may serve to offset this reduction in HF rats with greater effects in females. NEW & NOTEWORTHY Interstitial Po2 (Po2is; indicative of O2 delivery-to-utilization matching) determines, in part, O2 flux into skeletal muscle. We show that heart failure (HF) reduces Po2is at rest and during skeletal muscle contractions in rats and this negative effect is amplified for females. However, elevating NO bioavailability with dietary nitrate supplementation increases resting Po2is and alters the dynamic response with greater efficacy in female HF rats, particularly at rest and following the onset of muscle contractions.
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Affiliation(s)
- Jesse C Craig
- Department of Kinesiology, Kansas State University , Manhattan, Kansas
| | - Trenton D Colburn
- Department of Kinesiology, Kansas State University , Manhattan, Kansas
| | - Daniel M Hirai
- Department of Kinesiology, Kansas State University , Manhattan, Kansas
| | - Timothy I Musch
- Department of Kinesiology, Kansas State University , Manhattan, Kansas.,Department of Anatomy and Physiology, Kansas State University , Manhattan, Kansas
| | - David C Poole
- Department of Kinesiology, Kansas State University , Manhattan, Kansas.,Department of Anatomy and Physiology, Kansas State University , Manhattan, Kansas
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30
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de Castro TF, de Assis Manoel F, Figueiredo DH, Figueiredo DH, Machado FA. Effects of chronic beetroot juice supplementation on maximum oxygen uptake, velocity associated with maximum oxygen uptake, and peak velocity in recreational runners: a double-blinded, randomized and crossover study. Eur J Appl Physiol 2019; 119:1043-1053. [DOI: 10.1007/s00421-019-04094-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 02/06/2019] [Indexed: 12/17/2022]
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31
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Hill EC, Housh TJ, Smith CM, Keller JL, Schmidt RJ, Johnson GO. The Contributions of Arterial Cross-Sectional Area and Time-Averaged Flow Velocity to Arterial Blood Flow. J Med Ultrasound 2019; 26:186-193. [PMID: 30662149 PMCID: PMC6314092 DOI: 10.4103/jmu.jmu_20_18] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 01/02/2018] [Indexed: 11/09/2022] Open
Abstract
Background: Ultrasound has been used for noninvasive assessments of endothelial function in both clinical and athletic settings and to identify changes in muscle blood flow in response to exercise, nutritional supplementation, and occlusion. The purposes of the present study were to examine the reliability and relative contributions of arterial cross-sectional area and time-averaged flow velocity to predict muscle blood flow as a result of fatiguing exercise in men and women. Methods: Eighteen healthy men and 18 healthy women performed 50 consecutive eccentric repetitions of the elbow flexors at 60% of their pretest eccentric peak torque at a velocity of 180° s−1. Test-retest reliability and stepwise linear regression analyses were performed to determine the ability of arterial cross-sectional area and time-averaged flow velocity to predict brachial artery muscle blood flow for the men, women, and combined sample. Results: There was no systematic test versus retest mean differences (P > 0.05) for any of the ultrasound determined variables. The two-variable regression models significantly improved the ability to predict muscle blood flow and were associated with smaller standard error of the estimates (3.7%–10.1% vs. 16.8%–37.0% of the mean baseline muscle blood flow values) compared to the one-variable models. Conclusions: The findings of the present study supported the use of ultrasound for reliable assessments of arterial diameter, arterial cross-sectional area, time-averaged flow velocity, and muscle blood flow from the brachial artery in men and women. Furthermore, time-averaged flow velocity was a more powerful predictor of muscle blood flow than arterial cross-sectional area.
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Affiliation(s)
- Ethan C Hill
- Department of Nutrition and Health Sciences, Human Performance Laboratory, University of Nebraska-Lincoln, Lincoln, NE 68505, USA
| | - Terry J Housh
- Department of Nutrition and Health Sciences, Human Performance Laboratory, University of Nebraska-Lincoln, Lincoln, NE 68505, USA
| | - Cory M Smith
- Department of Nutrition and Health Sciences, Human Performance Laboratory, University of Nebraska-Lincoln, Lincoln, NE 68505, USA
| | - Joshua L Keller
- Department of Nutrition and Health Sciences, Human Performance Laboratory, University of Nebraska-Lincoln, Lincoln, NE 68505, USA
| | - Richard J Schmidt
- Department of Nutrition and Health Sciences, Human Performance Laboratory, University of Nebraska-Lincoln, Lincoln, NE 68505, USA
| | - Glen O Johnson
- Department of Nutrition and Health Sciences, Human Performance Laboratory, University of Nebraska-Lincoln, Lincoln, NE 68505, USA
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32
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Richards JC, Racine ML, Hearon CM, Kunkel M, Luckasen GJ, Larson DG, Allen JD, Dinenno FA. Acute ingestion of dietary nitrate increases muscle blood flow via local vasodilation during handgrip exercise in young adults. Physiol Rep 2019; 6. [PMID: 29380952 PMCID: PMC5789727 DOI: 10.14814/phy2.13572] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 12/13/2017] [Indexed: 12/04/2022] Open
Abstract
Dietary nitrate (NO3−) is converted to nitrite (NO2−) and can be further reduced to the vasodilator nitric oxide (NO) amid a low O2 environment. Accordingly, dietary NO3− increases hind limb blood flow in rats during treadmill exercise; however, the evidence of such an effect in humans is unclear. We tested the hypothesis that acute dietary NO3− (via beetroot [BR] juice) increases forearm blood flow (FBF) via local vasodilation during handgrip exercise in young adults (n = 11; 25 ± 2 years). FBF (Doppler ultrasound) and blood pressure (Finapres) were measured at rest and during graded handgrip exercise at 5%, 15%, and 25% maximal voluntary contraction (MVC) lasting 4 min each. At the highest workload (25% MVC), systemic hypoxia (80% SaO2) was induced and exercise continued for three additional minutes. Subjects ingested concentrated BR (12.6 mmol nitrate (n = 5) or 16.8 mmol nitrate (n = 6) and repeated the exercise bout either 2 (12.6 mmol) or 3 h (16.8 mmol) postconsumption. Compared to control, BR significantly increased FBF at 15% MVC (184 ± 15 vs. 164 ± 15 mL/min), 25% MVC (323 ± 27 vs. 286 ± 28 mL/min), and 25% + hypoxia (373 ± 39 vs. 343 ± 32 mL/min) and this was due to increases in vascular conductance (i.e., vasodilation). The effect of BR on hemodynamics was not different between the two doses of BR ingested. Forearm VO2 was also elevated during exercise at 15% and 25% MVC. We conclude that acute increases in circulating NO3− and NO2− via BR increases muscle blood flow during moderate‐ to high‐intensity handgrip exercise via local vasodilation. These findings may have important implications for aging and diseased populations that demonstrate impaired muscle perfusion and exercise intolerance.
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Affiliation(s)
- Jennifer C Richards
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Center for Cardiovascular Research, Colorado State University, Fort Collins, Colorado, USA
| | - Matthew L Racine
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Center for Cardiovascular Research, Colorado State University, Fort Collins, Colorado, USA
| | - Christopher M Hearon
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Center for Cardiovascular Research, Colorado State University, Fort Collins, Colorado, USA
| | - Megan Kunkel
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Center for Cardiovascular Research, Colorado State University, Fort Collins, Colorado, USA
| | - Gary J Luckasen
- Medical Center of the Rockies Foundation, Poudre Valley Health System, Loveland, Colorado, USA
| | - Dennis G Larson
- Medical Center of the Rockies Foundation, Poudre Valley Health System, Loveland, Colorado, USA
| | - Jason D Allen
- Department of Kinesiology, Curry School of Education, University of Virginia, Charlottesville, Virginia, USA.,Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, USA
| | - Frank A Dinenno
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Center for Cardiovascular Research, Colorado State University, Fort Collins, Colorado, USA
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33
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Caldwell JT, Sutterfield SL, Post HK, Craig JC, Baumfalk DR, Copp SW, Ade CJ. Impact of Acute Dietary Nitrate Supplementation during Exercise in Hypertensive Women. Med Sci Sports Exerc 2018; 51:1014-1021. [PMID: 30531488 DOI: 10.1249/mss.0000000000001857] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
INTRODUCTION the aim of the current investigation was to examine if dietary nitrate supplementation would improve vascular control in hypertensive postmenopausal women (PMW). We tested the hypotheses that acute dietary nitrate supplementation would 1) significantly decrease arterial blood pressure (BP) at rest and during exercise, 2) increase limb blood flow during steady-state (SS) exercise, and 3) improve functional sympatholysis during SS exercise. METHODS Ten hypertensive PMW underwent a randomized, double-blind, placebo-controlled trial with a nitrate-rich (NR) or nitrate-poor (NP) supplement. Beat-by-beat BP and heart rate were recorded throughout the trial on the nonexercising limb. Forearm blood flow was measured via ultrasonography on the brachial artery of the exercising limb. All patients performed a resting cold pressor test (CPT) (2 min) and then 7 min of submaximal handgrip exercise with a CPT applied during minutes 5-7. RESULTS SS systolic (NR, 170 ± 7; NP, 171 ± 37 mm Hg), diastolic (NR, 89 ± 2; NP, 92 ± 2 mm Hg), and mean arterial (NR, 121 ± 4; NP, 123 ± 2 mm Hg) pressures were not different between NP and NR treatment conditions (P > 0.05). During SS exercise, forearm blood flow (NR, 189 ± 8; NP, 218 ± 8 mL·min; P = 0.03) in the NR treatment was significantly lower compared with NP. When the CPT was applied during minutes 6-7 of exercise, forearm vascular conductance was reduced by 15% in the NR condition, but only 7% in the NR condition. CONCLUSIONS In summary, an acute NR supplement improved functional sympatholysis by ~50% versus an NP placebo condition. Improvements in functional sympatholysis may have important implications regarding exercise tolerance in hypertensive PMW.
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Affiliation(s)
- Jacob T Caldwell
- Department of Kinesiology, Kansas State University, Manhattan, KS
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Ross MD. Endothelial Regenerative Capacity and Aging: Influence of Diet, Exercise and Obesity. Curr Cardiol Rev 2018; 14:233-244. [PMID: 30047332 PMCID: PMC6300798 DOI: 10.2174/1573403x14666180726112303] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 06/20/2018] [Accepted: 06/22/2018] [Indexed: 12/23/2022] Open
Abstract
Background: The endothelium plays an important role in cardiovascular regulation, from blood flow to platelet aggregation, immune cell infiltration and demargination. A dysfunctional endo-thelium leads to the onset and progression of Cardiovascular Disease (CVD). The aging endothelium displays significant alterations in function, such as reduced vasomotor functions and reduced angio-genic capabilities. This could be partly due to elevated levels of oxidative stress and reduced endothe-lial cell turnover. Circulating angiogenic cells, such as Endothelial Progenitor Cells (EPCs) play a significant role in maintaining endothelial health and function, by supporting endothelial cell prolifera-tion, or via incorporation into the vasculature and differentiation into mature endothelial cells. Howev-er, these cells are reduced in number and function with age, which may contribute to the elevated CVD risk in this population. However, lifestyle factors, such as exercise, physical activity obesity, and dietary intake of omega-3 polyunsaturated fatty acids, nitrates, and antioxidants, significantly af-fect the number and function of these circulating angiogenic cells. Conclusion: This review will discuss the effects of advancing age on endothelial health and vascular regenerative capacity, as well as the influence of diet, exercise, and obesity on these cells, the mecha-nistic links and the subsequent impact on cardiovascular health
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Affiliation(s)
- Mark D Ross
- School of Applied Sciences, Edinburgh Napier University, Edinburgh, United Kingdom
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35
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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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36
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Coggan AR, Peterson LR. Dietary Nitrate Enhances the Contractile Properties of Human Skeletal Muscle. Exerc Sport Sci Rev 2018; 46:254-261. [PMID: 30001275 PMCID: PMC6138552 DOI: 10.1249/jes.0000000000000167] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
We review recent studies of the effects of dietary nitrate on human muscle contractile function and discuss possible underlying mechanisms. Dietary nitrate, a source of nitric oxide (NO), improves the contractile properties of human muscle. We present the hypothesis that this is due to nitrosylation of the ryanodine receptor and increased NO signaling via the soluble guanyl cyclase-cyclic guanosine monophosphate-protein kinase G pathway, which together increase the free intracellular Ca2+ concentration along with the Ca2+ sensitivity of the myofilaments themselves.
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Affiliation(s)
- Andrew R Coggan
- Departments of Kinesiology and.,Cellular and Integrative Physiology, Indiana University Purdue University Indianapolis, Indianapolis, IN
| | - Linda R Peterson
- Medicine and.,Radiology, Washington University School of Medicine, St. Louis, MO
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37
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Edwards TM, Hamlin HJ. Reproductive endocrinology of environmental nitrate. Gen Comp Endocrinol 2018; 265:31-40. [PMID: 29577898 DOI: 10.1016/j.ygcen.2018.03.021] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 03/19/2018] [Accepted: 03/20/2018] [Indexed: 12/19/2022]
Abstract
Nitrate is a widespread contaminant of aquatic ecosystems and drinking water. It is also broadly active in organismal physiology, and as such, has the potential to both enhance and disrupt normal physiological function. In animals, nitrate is a proposed endocrine disrupter that is converted in vivo to nitrite and nitric oxide. Nitric oxide, in particular, is a potent cell signaling molecule that participates in diverse biological pathways and events. Here, we review in vivo nitrate cycling and downstream mechanistic physiology, with an emphasis on reproductive outcomes. However, in many cases, the research produces contradictory results, in part because there is good evidence that nitrate follows a non-monotonic dose-response curve. This conundrum highlights an array of opportunities for scientists from different fields to collaborate for a full understanding of nitrate physiology. Opposing conclusions are especially likely when in vivo/in vitro, long term/short term, high dose/low dose, or hypoxia/normoxia studies are compared. We conclude that in vivo studies are most appropriate for testing an organism's integrated endocrine response to nitrate. Based on the limited available studies, there is a generalized trend that shorter term studies (less than 1 month) or studies involving low doses (≤5 mg/L NO3-N) cause steroid hormone levels to decline. Studies that last more than a month and/or involve higher, but still environmentally relevant, exposures (>50-100 mg/L NO3-N) cause steroid hormone levels to increase. Very high nitrate doses (>500 mg/L NO3-N) are cytotoxic in many species. Hypoxia and acidity are likely to intensify the effects of nitrate. For study design, degree of study animal reproductive maturity or activity is important, with immature/reproductively quiescent animals responding to nitrate differently, compared with reproductively active animals. A detailed table of studies is presented.
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Affiliation(s)
- Thea M Edwards
- Department of Biology, University of the South, Sewanee, TN, USA.
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38
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Vanhatalo A, Blackwell JR, L'Heureux JE, Williams DW, Smith A, van der Giezen M, Winyard PG, Kelly J, Jones AM. Nitrate-responsive oral microbiome modulates nitric oxide homeostasis and blood pressure in humans. Free Radic Biol Med 2018; 124:21-30. [PMID: 29807159 PMCID: PMC6191927 DOI: 10.1016/j.freeradbiomed.2018.05.078] [Citation(s) in RCA: 112] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 04/19/2018] [Accepted: 05/21/2018] [Indexed: 11/24/2022]
Abstract
Imbalances in the oral microbial community have been associated with reduced cardiovascular and metabolic health. A possible mechanism linking the oral microbiota to health is the nitrate (NO3-)-nitrite (NO2-)-nitric oxide (NO) pathway, which relies on oral bacteria to reduce NO3- to NO2-. NO (generated from both NO2- and L-arginine) regulates vascular endothelial function and therefore blood pressure (BP). By sequencing bacterial 16S rRNA genes we examined the relationships between the oral microbiome and physiological indices of NO bioavailability and possible changes in these variables following 10 days of NO3- (12 mmol/d) and placebo supplementation in young (18-22 yrs) and old (70-79 yrs) normotensive humans (n = 18). NO3- supplementation altered the salivary microbiome compared to placebo by increasing the relative abundance of Proteobacteria (+225%) and decreasing the relative abundance of Bacteroidetes (-46%; P < 0.05). After NO3-supplementation the relative abundances of Rothia (+127%) and Neisseria (+351%) were greater, and Prevotella (-60%) and Veillonella (-65%) were lower than in the placebo condition (all P < 0.05). NO3- supplementation increased plasma concentration of NO2- and reduced systemic blood pressure in old (70-79 yrs), but not young (18-22 yrs), participants. High abundances of Rothia and Neisseria and low abundances of Prevotella and Veillonella were correlated with greater increases in plasma [NO2-] in response to NO3- supplementation. The current findings indicate that the oral microbiome is malleable to change with increased dietary intake of inorganic NO3-, and that diet-induced changes in the oral microbial community are related to indices of NO homeostasis and vascular health in vivo.
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Affiliation(s)
- Anni Vanhatalo
- College of Life and Environmental Sciences, University of Exeter, Exeter EX1 1TE, UK.
| | - Jamie R Blackwell
- College of Life and Environmental Sciences, University of Exeter, Exeter EX1 1TE, UK
| | - Joanna E L'Heureux
- College of Life and Environmental Sciences, University of Exeter, Exeter EX1 1TE, UK
| | | | - Ann Smith
- Division of Population Medicine, Cardiff University, Cardiff CF14 4XY UK
| | - Mark van der Giezen
- College of Life and Environmental Sciences, University of Exeter, Exeter EX1 1TE, UK
| | - Paul G Winyard
- University of Exeter Medical School, University of Exeter, Exeter EX1 1TE, UK
| | - James Kelly
- College of Life and Environmental Sciences, University of Exeter, Exeter EX1 1TE, UK
| | - Andrew M Jones
- College of Life and Environmental Sciences, University of Exeter, Exeter EX1 1TE, UK
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39
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Schneider AC, Hughes WE, Ueda K, Bock JM, Casey DP. Reduced blood pressure responsiveness to skeletal muscle metaboreflex activation in older adults following inorganic nitrate supplementation. Nitric Oxide 2018; 78:81-88. [DOI: 10.1016/j.niox.2018.05.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 05/24/2018] [Accepted: 05/31/2018] [Indexed: 01/25/2023]
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40
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Craig JC, Broxterman RM, Smith JR, Allen JD, Barstow TJ. Effect of dietary nitrate supplementation on conduit artery blood flow, muscle oxygenation, and metabolic rate during handgrip exercise. J Appl Physiol (1985) 2018; 125:254-262. [DOI: 10.1152/japplphysiol.00772.2017] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Dietary nitrate supplementation has positive effects on mitochondrial and muscle contractile efficiency during large muscle mass exercise in humans and on skeletal muscle blood flow (Q̇) in rats. However, concurrent measurement of these effects has not been performed in humans. Therefore, we assessed the influence of nitrate supplementation on Q̇ and muscle oxygenation characteristics during moderate- (40 %peak) and severe-intensity(85% peak) handgrip exercise in a randomized, double-blind, crossover design. Nine healthy men (age: 25 ± 2 yr) completed four constant-power exercise tests (2/intensity) randomly assigned to condition [nitrate-rich (nitrate) or nitrate-poor (placebo) beetroot supplementation] and intensity (40 or 85% peak). Resting mean arterial pressure was lower after nitrate compared with placebo (84 ± 4 vs. 89 ± 4 mmHg, P < 0.01). All subjects were able to sustain 10 min of exercise at 40% peak in both conditions. Nitrate had no effect on exercise tolerance during 85% peak (nitrate: 358 ± 29; placebo: 341 ± 34 s; P = 0.3). Brachial artery Q̇ was not different after nitrate at rest or any time during exercise. Deoxygenated [hemoglobin + myoglobin] was not different for 40% peak ( P > 0.05) but was elevated throughout 85% peak ( P < 0.05) after nitrate. The metabolic cost (V̇o2) was not different at the end of exercise; however, the V̇o2 primary amplitude at the onset of exercise was elevated after nitrate for the 85% peak work rate (96 ± 20 vs. 72 ± 12 ml/min, P < 0.05) and had a faster response. These findings suggest that an acute dose of nitrate reduces resting blood pressure and speeds V̇o2 kinetics in young adults but does not augment Q̇ or reduce steady-state V̇o2 during small muscle mass handgrip exercise. NEW & NOTEWORTHY We show that acute dietary nitrate supplementation via beetroot juice increases the amplitude and speed of local muscle V̇o2 on kinetics parameters during severe- but not moderate-intensity handgrip exercise. These changes were found in the absence of an increased blood flow response, suggesting that the increased V̇o2 was attained via improvements in fractional O2 extraction and/or spatial distribution of blood flow within the exercising muscle.
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Affiliation(s)
- Jesse C. Craig
- Department of Kinesiology, Kansas State University, Manhattan, Kansas
| | - Ryan M. Broxterman
- Department of Kinesiology, Kansas State University, Manhattan, Kansas
- Department of Anatomy and Physiology, Kansas State University, Manhattan, Kansas
| | - Joshua R. Smith
- Department of Kinesiology, Kansas State University, Manhattan, Kansas
| | - Jason D. Allen
- Department of Medicine, Duke University Medical Center, Durham, North Carolina
- Department of Kinesiology, University of Virginia, Charlottesville, Virginia
| | - Thomas J. Barstow
- Department of Kinesiology, Kansas State University, Manhattan, Kansas
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41
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Kruse NT, Ueda K, Hughes WE, Casey DP. Eight weeks of nitrate supplementation improves blood flow and reduces the exaggerated pressor response during forearm exercise in peripheral artery disease. Am J Physiol Heart Circ Physiol 2018. [PMID: 29522355 DOI: 10.1152/ajpheart.00015.2018] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Peripheral artery disease (PAD) is characterized by a reduced blood flow (BF) and an elevated blood pressure (pressor) response during lower extremity exercise. Although PAD is evident in the upper extremities, no studies have determined BF and pressor responses during upper extremity exercise in PAD. Emerging evidence suggests that inorganic nitrate supplementation may serve as an alternative dietary strategy to boost nitric oxide bioavailability, improving exercising BF and pressor responses during exercise. The present study investigated 1) BF and pressor responses to forearm exercise in patients with PAD ( n = 21) relative to healthy age-matched control subjects ( n = 16) and 2) whether 8 wk of NaNO3 supplementation influenced BF and pressor responses to forearm exercise in patients with PAD. Patients with moderate to severe PAD were randomly assigned to a NaNO3 (1 g/day, n = 13)-treated group or a placebo (microcrystalline cellulose, n = 8)-treated group. Brachial artery forearm BF (FBF; via Doppler) and blood pressure (via finger plethysmography) were measured during mild-intensity (~3.5-kg) and moderate-intensity (~7-kg) handgrip exercise. The absolute change (from baseline) in FBF was reduced (except in the 3.5-kg condition) and BP responses were increased in patients with PAD compared with healthy control subjects in 3.5- and 7-kg conditions (all P < 0.05). Plasma nitrate and nitrite were elevated, exercising (7-kg) ΔFBF was improved (from 141 ± 17 to 172 ± 20 ml/min), and mean arterial pressure response was reduced (from 13 ± 1 to 9 ± 1 mmHg, P < 0.05) in patients with PAD that received NaNO3 supplementation for 8 wk relative to those that received placebo. These results suggest that the BF limitation and exaggerated pressor response to moderate-intensity forearm exercise in patients with PAD are improved with 8 wk of NaNO3 supplementation. NEW & NOTEWORTHY Peripheral artery disease (PAD) results in an exaggerated pressor response and reduced blood flow during lower limb exercise; however, the effect of PAD in the upper limbs has remained unknown. These results suggest that 8 wk of inorganic nitrate supplementation improves the blood flow limitation and exaggerated pressor response to moderate-intensity forearm exercise in PAD.
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Affiliation(s)
- Nicholas T Kruse
- Department of Physical Therapy and Rehabilitation Science, Carver College of Medicine, University of Iowa , Iowa City, Iowa.,Abboud Cardiovascular Research Center, Carver College of Medicine, University of Iowa , Iowa City, Iowa
| | - Kenichi Ueda
- Department of Anesthesia, Carver College of Medicine, University of Iowa , Iowa City, Iowa
| | - William E Hughes
- Department of Physical Therapy and Rehabilitation Science, Carver College of Medicine, University of Iowa , Iowa City, Iowa
| | - Darren P Casey
- Department of Physical Therapy and Rehabilitation Science, Carver College of Medicine, University of Iowa , Iowa City, Iowa.,Abboud Cardiovascular Research Center, Carver College of Medicine, University of Iowa , Iowa City, Iowa.,Fraternal Order of Eagles Diabetes Research, Carver College of Medicine, University of Iowa , Iowa City, Iowa
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42
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Inorganic nitrate alleviates the senescence-related decline in liver function. SCIENCE CHINA-LIFE SCIENCES 2018; 61:24-34. [DOI: 10.1007/s11427-017-9207-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2017] [Accepted: 10/26/2017] [Indexed: 12/23/2022]
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43
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Wong BJ, Keen JT, Levitt EL. Cutaneous reactive hyperaemia is unaltered by dietary nitrate supplementation in healthy humans. Clin Physiol Funct Imaging 2017; 38:772-778. [DOI: 10.1111/cpf.12478] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 10/02/2017] [Indexed: 12/16/2022]
Affiliation(s)
- Brett J Wong
- Department of Kinesiology, Kansas State University, Manhattan, KS, USA.,Department of Kinesiology & Health, Georgia State University, Atlanta, GA, USA
| | - Jeremy T Keen
- Department of Kinesiology, Kansas State University, Manhattan, KS, USA
| | - Erica L Levitt
- Department of Kinesiology, Kansas State University, Manhattan, KS, USA
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44
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Kellawan JM, Limberg JK, Scruggs ZM, Nicholson WT, Schrage WG, Joyner MJ, Curry TB. Phosphodiesterase-5 inhibition preserves exercise-onset vasodilator kinetics when NOS activity is reduced. J Appl Physiol (1985) 2017; 124:276-282. [PMID: 28982942 DOI: 10.1152/japplphysiol.00483.2017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Nitric oxide (NO)-mediated vasodilation contributes to the rapid rise in muscle blood flow at exercise onset. This occurs via increased cyclic guanosine monophosphate (cGMP), which is catabolized by phosphodiesterase-5 (PDE-5). Whether PDE-5 limits exercise vasodilation onset kinetics is unknown. We hypothesized the time course of exercise vasodilation would be 1) accelerated during PDE-5 inhibition (sildenafil citrate, SDF) and 2) decelerated during NO synthase inhibition ( NG-monomethyl-l-arginine, l-NMMA), and 3) the effect of SDF on vasodilation onset kinetics would be attenuated with concurrent l-NMMA. Data from 29 healthy adults were analyzed. Individuals completed 5 min of moderate-intensity forearm exercise under control conditions and during 1) oral SDF ( n = 8), 2) intra-arterial l-NMMA ( n = 15), or 3) combined SDF + l-NMMA ( n = 6). Forearm blood flow (FBF; Doppler ultrasound of the brachial artery) and mean brachial artery blood pressure (MAP) were measured continuously. Forearm vascular conductance (FVC, FBF ÷ MAP) was curve-fit with a monoexponential model, and vasodilation onset kinetics were assessed by mean response time (MRT, time to achieve 63% of steady state). SDF had no effect on MRT ( P = 0.90). NOS inhibition increased MRT ( P = 0.01). MRT during SDF+l-NMMA was not different from control exercise ( P = 0.76). PDE-5 inhibition alone has no effect on rapid-onset vasodilation. Whereas NOS inhibition decelerates vasodilator kinetics, when combined with SDF, vasodilator kinetics do not differ from control. These data suggest NO-independent activation of cGMP occurs at exercise onset; thus PDE-5 inhibition may improve vasodilation in pathologies where NO bioavailability is impaired. NEW & NOTEWORTHY We show that when NO bioavailability is reduced, PDE-5 inhibition can restore vasodilation onset kinetics of exercise-mediated vasodilation via NO-independent cGMP pathways. These data suggest PDE-5 inhibition may improve exercise vasodilation onset kinetics in pathologies where NO bioavailability is impaired.
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Affiliation(s)
- J Mikhail Kellawan
- Department of Kinesiology, University of Wisconsin , Madison, Wisconsin.,Department of Health and Exercise Science, University of Oklahoma , Norman, Oklahoma
| | - Jacqueline K Limberg
- Department of Anesthesiology, Mayo Clinic College of Medicine , Rochester, Minnesota
| | - Zachariah M Scruggs
- Department of Anesthesiology, Mayo Clinic College of Medicine , Rochester, Minnesota
| | - Wayne T Nicholson
- Department of Anesthesiology, Mayo Clinic College of Medicine , Rochester, Minnesota
| | - William G Schrage
- Department of Kinesiology, University of Wisconsin , Madison, Wisconsin.,Department of Anesthesiology, Mayo Clinic College of Medicine , Rochester, Minnesota
| | - Michael J Joyner
- Department of Anesthesiology, Mayo Clinic College of Medicine , Rochester, Minnesota
| | - Timothy B Curry
- Department of Anesthesiology, Mayo Clinic College of Medicine , Rochester, Minnesota
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Effect of oxidative stress on racial differences in vascular function at rest and during hand grip exercise. J Hypertens 2017; 35:2006-2015. [DOI: 10.1097/hjh.0000000000001433] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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Gasier HG, Reinhold AR, Loiselle AR, Soutiere SE, Fothergill DM. Effects of oral sodium nitrate on forearm blood flow, oxygenation and exercise performance during acute exposure to hypobaric hypoxia (4300 m). Nitric Oxide 2017; 69:1-9. [DOI: 10.1016/j.niox.2017.07.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Revised: 06/16/2017] [Accepted: 07/01/2017] [Indexed: 10/19/2022]
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Bentley RF, Walsh JJ, Drouin PJ, Velickovic A, Kitner SJ, Fenuta AM, Tschakovsky ME. Dietary nitrate restores compensatory vasodilation and exercise capacity in response to a compromise in oxygen delivery in the noncompensator phenotype. J Appl Physiol (1985) 2017; 123:594-605. [PMID: 28596274 DOI: 10.1152/japplphysiol.00953.2016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 06/07/2017] [Accepted: 06/07/2017] [Indexed: 12/16/2022] Open
Abstract
Recently, dietary nitrate supplementation has been shown to improve exercise capacity in healthy individuals through a potential nitrate-nitrite-nitric oxide pathway. Nitric oxide has been shown to play an important role in compensatory vasodilation during exercise under hypoperfusion. Previously, we established that certain individuals lack a vasodilation response when perfusion pressure reductions compromise exercising muscle blood flow. Whether this lack of compensatory vasodilation in healthy, young individuals can be restored with dietary nitrate supplementation is unknown. Six healthy (21 ± 2 yr), recreationally active men completed a rhythmic forearm exercise. During steady-state exercise, the exercising arm was rapidly transitioned from an uncompromised (below heart) to a compromised (above heart) position, resulting in a reduction in local pressure of -31 ± 1 mmHg. Exercise was completed following 5 days of nitrate-rich (70 ml, 0.4 g nitrate) and nitrate-depleted (70 ml, ~0 g nitrate) beetroot juice consumption. Forearm blood flow (in milliliters per minute; brachial artery Doppler and echo ultrasound), mean arterial blood pressure (in millimeters of mercury; finger photoplethysmography), exercising forearm venous effluent (ante-cubital vein catheter), and plasma nitrite concentrations (chemiluminescence) revealed two distinct vasodilatory responses: nitrate supplementation increased (plasma nitrite) compared with placebo (245 ± 60 vs. 39 ± 9 nmol/l; P < 0.001), and compensatory vasodilation was present following nitrate supplementation (568 ± 117 vs. 714 ± 139 ml ⋅ min-1 ⋅ 100 mmHg-1; P = 0.005) but not in placebo (687 ± 166 vs. 697 ± 171 min-1 ⋅ 100 mmHg-1; P = 0.42). As such, peak exercise capacity was reduced to a lesser degree (-4 ± 39 vs. -39 ± 27 N; P = 0.01). In conclusion, dietary nitrate supplementation during a perfusion pressure challenge is an effective means of restoring exercise capacity and enabling compensatory vasodilation.NEW & NOTEWORTHY Previously, we identified young, healthy persons who suffer compromised exercise tolerance when exercising muscle perfusion pressure is reduced as a result of a lack of compensatory vasodilation. The ability of nitrate supplementation to restore compensatory vasodilation in such noncompensators is unknown. We demonstrated that beetroot juice supplementation led to compensatory vasodilation and restored perfusion and exercise capacity. Elevated plasma nitrite is an effective intervention for correcting the absence of compensatory vasodilation in the noncompensator phenotype.
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Affiliation(s)
- Robert F Bentley
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada
| | - Jeremy J Walsh
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada
| | - Patrick J Drouin
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada
| | - Aleksandra Velickovic
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada
| | - Sarah J Kitner
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada
| | - Alyssa M Fenuta
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada
| | - Michael E Tschakovsky
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada
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Potentiation of the NO-cGMP pathway and blood flow responses during dynamic exercise in healthy humans. Eur J Appl Physiol 2016; 117:237-246. [PMID: 28013386 DOI: 10.1007/s00421-016-3523-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 12/19/2016] [Indexed: 10/20/2022]
Abstract
PURPOSE Previous work has shown nitric oxide (NO) contributes to ~15% of the hyperemic response to dynamic exercise in healthy humans. This NO-mediated vasodilation occurs, in part, via increases in intracellular cyclic guanosine monophosphate (cGMP), which is catabolized by phosphodiesterase. We sought to examine the effect of phosphodiesterase-5 (PDE-5) inhibition on forearm blood flow (FBF) responses to dynamic handgrip exercise in healthy humans and the role of NO. We hypothesized exercise hyperemia would be augmented by sildenafil citrate (SDF, PDE-5 inhibitor). We further hypothesized any effect of SDF on exercise hyperemia would be abolished with intra-arterial infusion of the NO synthase (NOS) inhibitor L-NG-monomethyl arginine (L-NMMA). METHODS FBF (Doppler ultrasound) was assessed at rest and during 5 min of dynamic forearm handgrip exercise at 15% of maximal voluntary contraction under control (saline) conditions and during 3 experimental protocols: (1) oral SDF (n = 10), (2) intra-arterial L-NMMA (n = 20), (3) SDF and L-NMMA (n = 10). FBF responses to intra-arterial sodium nitroprusside (NTP, NO donor) were also assessed. RESULTS FBF increased with exercise (p < 0.01). Intra-arterial infusion of L-NMMA resulted in a reduction in exercise hyperemia (17 ± 1 to 15 ± 1 mL/dL/min, p < 0.01). Although the hyperemic response to NTP was augmented by SDF (area under the curve: 41 ± 7 vs 61 ± 11 AU, p < 0.01), there was no effect of SDF on exercise hyperemia (p = 0.33). CONCLUSIONS Despite improving NTP-mediated vasodilation, oral SDF failed to augment exercise hyperemia in young, healthy adults. These observations reflect a minor contribution of NO and the cGMP pathway during exercise hyperemia in healthy young humans.
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Siervo M, Oggioni C, Jakovljevic DG, Trenell M, Mathers JC, Houghton D, Celis-Morales C, Ashor AW, Ruddock A, Ranchordas M, Klonizakis M, Williams EA. Dietary nitrate does not affect physical activity or outcomes in healthy older adults in a randomized, cross-over trial. Nutr Res 2016; 36:1361-1369. [PMID: 27890482 DOI: 10.1016/j.nutres.2016.11.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 11/07/2016] [Accepted: 11/10/2016] [Indexed: 12/17/2022]
Abstract
Although dietary nitrate (NO3-) ingestion appears to enhance exercise capacity and performance in young individuals, inconclusive findings have been reported in older people. Therefore, we conducted a double-blind, crossover randomized clinical trial using beetroot juice in older healthy participants, who were classified as normal weight and overweight. We tested whether consumption of beetroot juice (a rich source of NO3-) for 1 week would increase nitric oxide bioavailability via the nonenzymatic pathway and enhance (1) exercise capacity during an incremental exercise test, (2) physical capability, and (3) free-living physical activity. Twenty nonsmoking, healthy participants between 60 and 75 years of age and with a body mass index of 20.0 to 29.9 kg/m2 were included. Presupplementation and postsupplementation resting, submaximal, maximal, and recovery gas exchanges were measured. Physical capability was measured by hand-grip strength, time-up-and-go, repeated chair rising test, and 10-m walking speed. Free-living physical activity was assessed by triaxal accelerometry. Changes in urinary and plasmaNO3-concentrations were measured by gas chromatography-mass spectrometry. Nineteen participants (male-to-female ratio, 9:10) completed the study.Beetroot juice increased significantly both plasma and urinary NO3-concentrations (P<.001) when compared with placebo. Beetroot juice did not influence resting or submaximal and maximal oxygen consumption during the incremental exercise test. In addition, measures of physical capability and physical activity levels measured in free-living conditions were not modified by beetroot juice ingestion. The positive effects of beetroot juice ingestion on exercise performance seen in young individuals were not replicated in healthy, older adults. Whether aging represents a modifier of the effects of dietary NO3-on muscular performance is not known, and mechanistic studies and larger trials are needed to test this hypothesis.
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Affiliation(s)
- Mario Siervo
- Human Nutrition Research Centre, Institute of Cellular Medicine, Newcastle University, Campus for Ageing and Vitality, Newcastle on Tyne, NE4 5PL, UK.
| | - Clio Oggioni
- Human Nutrition Research Centre, Institute of Cellular Medicine, Newcastle University, Campus for Ageing and Vitality, Newcastle on Tyne, NE4 5PL, UK
| | - Djordje G Jakovljevic
- Institute of Cellular Medicine, MoveLab, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK; RCUK Centre for Ageing and Vitality, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Michael Trenell
- Institute of Cellular Medicine, MoveLab, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK; RCUK Centre for Ageing and Vitality, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - John C Mathers
- Human Nutrition Research Centre, Institute of Cellular Medicine, Newcastle University, Campus for Ageing and Vitality, Newcastle on Tyne, NE4 5PL, UK; RCUK Centre for Ageing and Vitality, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - David Houghton
- Institute of Cellular Medicine, MoveLab, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Carlos Celis-Morales
- Human Nutrition Research Centre, Institute of Cellular Medicine, Newcastle University, Campus for Ageing and Vitality, Newcastle on Tyne, NE4 5PL, UK
| | - Ammar W Ashor
- Human Nutrition Research Centre, Institute of Cellular Medicine, Newcastle University, Campus for Ageing and Vitality, Newcastle on Tyne, NE4 5PL, UK
| | - Alan Ruddock
- Centre for Sport and Exercise Science, Sheffield Hallam University, Sheffield, UK
| | - Mayur Ranchordas
- Centre for Sport and Exercise Science, Sheffield Hallam University, Sheffield, UK
| | - Markos Klonizakis
- Centre for Sport and Exercise Science, Sheffield Hallam University, Sheffield, UK
| | - Elizabeth A Williams
- Human Nutrition Unit, Department of Oncology, Faculty of Medicine, Dentistry and Health, University of Sheffield, Sheffield, S10 2RX, UK
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50
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Hennis PJ, Mitchell K, Gilbert-Kawai E, Bountziouka V, Wade A, Feelisch M, Grocott MP, Martin DS. Effects of dietary nitrate supplementation on symptoms of acute mountain sickness and basic physiological responses in a group of male adolescents during ascent to Mount Everest Base Camp. Nitric Oxide 2016; 60:24-31. [DOI: 10.1016/j.niox.2016.08.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 08/28/2016] [Accepted: 08/31/2016] [Indexed: 11/16/2022]
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