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Główka N, Malik J, Podgórski T, Stemplewski R, Maciaszek J, Ciążyńska J, Zawieja EE, Chmurzynska A, Nowaczyk PM, Durkalec-Michalski K. The dose-dependent effect of caffeine supplementation on performance, reaction time and postural stability in CrossFit - a randomized placebo-controlled crossover trial. J Int Soc Sports Nutr 2024; 21:2301384. [PMID: 38226646 PMCID: PMC10795626 DOI: 10.1080/15502783.2023.2301384] [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: 11/09/2023] [Accepted: 12/28/2023] [Indexed: 01/17/2024] Open
Abstract
BACKGROUND Caffeine (CAF) ingestion improves performance in a broad range of exercise tasks. Nevertheless, the CAF-induced, dose-dependent effect on discipline-specific performance and cognitive functions in CrossFit/High-Intensity Functional Training (HIFT) has not been sufficiently investigated. The aim of this study was to evaluate the effect of acute supplementation of three different doses of CAF and placebo (PLA) on specific performance, reaction time (RTime), postural stability (PStab), heart rate (HR) and perceived exertion (RPE). METHODS In a randomized double-blind placebo-controlled crossover design, acute pre-exercise supplementation with CAF (3, 6, or 9 mg/kg body mass (BM)) and PLA in 26 moderately trained CrossFit practitioners was examined. The study protocol involved five separate testing sessions using the Fight Gone Bad test (FGB) as the exercise performance evaluation and biochemical analyses, HR and RPE monitoring, as well as the assessment of RTime and PStab, with regard to CYP1A2 (rs762551) and ADORA2A (rs5751876) single nucleotide polymorphism (SNP). RESULTS Supplementation of 6 mgCAF/kgBM induced clinically noticeable improvements in FGBTotal results, RTime and pre-exercise motor time. Nevertheless, there were no significant differences between any CAF doses and PLA in FGBTotal, HRmax, HRmean, RPE, pre/post-exercise RTime, PStab variables or pyruvate concentrations. Lactate concentration was higher (p < 0.05) before and after exercise in all CAF doses than in PLA. There was no effect of CYP1A2 or ADORA2A SNPs on performance. CONCLUSIONS The dose-dependent effect of CAF supplementation appears to be limited to statistically nonsignificant but clinically considered changes on specific performance, RTime, PStab, RPE or HR. However, regarding practical CAF-induced performance implications in CrossFit/HIFT, 6 mgCAF/kgBM may be supposed as the most rational supplementation strategy.
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Affiliation(s)
- Natalia Główka
- Department of Sports Dietetics, Poznań University of Physical Education, Poznań, Poland
| | - Jakub Malik
- Department of Physical Activity and Health Promotion Science, Poznań University of Physical Education, Poznań, Poland
| | - Tomasz Podgórski
- Department of Physiology and Biochemistry, Poznań University of Physical Education, Poznań, Poland
| | - Rafał Stemplewski
- Department of Digital Technologies in Physical Activity, Poznań University of Physical Education, Poznań, Poland
| | - Janusz Maciaszek
- Department of Physical Activity and Health Promotion Science, Poznań University of Physical Education, Poznań, Poland
| | - Julia Ciążyńska
- Department of Physical Activity and Health Promotion Science, Poznań University of Physical Education, Poznań, Poland
| | - Emilia E. Zawieja
- Department of Human Nutrition and Dietetics, Poznań University of Life Sciences, Poznań, Poland
| | - Agata Chmurzynska
- Department of Human Nutrition and Dietetics, Poznań University of Life Sciences, Poznań, Poland
| | - Paulina M. Nowaczyk
- Department of Sports Dietetics, Poznań University of Physical Education, Poznań, Poland
| | - Krzysztof Durkalec-Michalski
- Department of Sports Dietetics, Poznań University of Physical Education, Poznań, Poland
- Sport Sciences–Biomedical Department, Faculty of Physical Education and Sport, Charles University, Prague, Czech Republic
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Glaister M, Lythgoe D, Kamath S. The Effects of Caffeine on Heart Rate and Heart Rate Variability at Rest and During Submaximal Cycling Exercise. RESEARCH QUARTERLY FOR EXERCISE AND SPORT 2024:1-9. [PMID: 39008947 DOI: 10.1080/02701367.2024.2377303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Accepted: 07/02/2024] [Indexed: 07/17/2024]
Abstract
The aim of this study was to investigate the effects of caffeine on heart rate and heart rate variability (HRV) at rest and during submaximal exercise. Using a balanced, double-blind, randomized, crossover design, 16 male cyclists (age: 37 ± 9 years; V ˙ O2max: 4.44 ± 0.67 L·min-1) completed three trials in an air-conditioned laboratory. In Trial 1, cyclists completed two incremental cycling tests to establish the V ˙ O2-power output relationship and V ˙ O2max. In trials 2 and 3, cyclists were evaluated for heart rate and HRV at rest, after which they ingested a capsule containing 5 mg·kg-1 of caffeine or placebo. Thirty-five minutes post-supplementation, additional resting heart rate and HRV readings were taken after which cyclists completed a submaximal incremental cycling test (6 min stages) at 40-80% of V ˙ O2max; with HR and HRV measurements taken in the last 5 min of each increment. HRV was determined from the root mean square of successive differences between R-R intervals. There were significant supplement × exercise intensity interactions on heart rate (p = .019) and HRV (p = .023), with post hoc tests on the latter showing that caffeine increased HRV at 40%, 50%, and 60% of V ˙ O2max by 3.6 ± 4.9, 2.6 ± 2.8, and 0.6 ± 1.7 ms, respectively. There was a supplement × time interaction effect on resting HRV (p < .001), but not on heart rate (p = .351). The results of this study support the suggestion that caffeine increases the parasympathetic modulation of heart rate.Clinical trial registration number: NCT05521386.
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McKenna MJ, Renaud JM, Ørtenblad N, Overgaard K. A century of exercise physiology: effects of muscle contraction and exercise on skeletal muscle Na +,K +-ATPase, Na + and K + ions, and on plasma K + concentration-historical developments. Eur J Appl Physiol 2024; 124:681-751. [PMID: 38206444 PMCID: PMC10879387 DOI: 10.1007/s00421-023-05335-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 09/27/2023] [Indexed: 01/12/2024]
Abstract
This historical review traces key discoveries regarding K+ and Na+ ions in skeletal muscle at rest and with exercise, including contents and concentrations, Na+,K+-ATPase (NKA) and exercise effects on plasma [K+] in humans. Following initial measures in 1896 of muscle contents in various species, including humans, electrical stimulation of animal muscle showed K+ loss and gains in Na+, Cl- and H20, then subsequently bidirectional muscle K+ and Na+ fluxes. After NKA discovery in 1957, methods were developed to quantify muscle NKA activity via rates of ATP hydrolysis, Na+/K+ radioisotope fluxes, [3H]-ouabain binding and phosphatase activity. Since then, it became clear that NKA plays a central role in Na+/K+ homeostasis and that NKA content and activity are regulated by muscle contractions and numerous hormones. During intense exercise in humans, muscle intracellular [K+] falls by 21 mM (range - 13 to - 39 mM), interstitial [K+] increases to 12-13 mM, and plasma [K+] rises to 6-8 mM, whilst post-exercise plasma [K+] falls rapidly, reflecting increased muscle NKA activity. Contractions were shown to increase NKA activity in proportion to activation frequency in animal intact muscle preparations. In human muscle, [3H]-ouabain-binding content fully quantifies NKA content, whilst the method mainly detects α2 isoforms in rats. Acute or chronic exercise affects human muscle K+, NKA content, activity, isoforms and phospholemman (FXYD1). Numerous hormones, pharmacological and dietary interventions, altered acid-base or redox states, exercise training and physical inactivity modulate plasma [K+] during exercise. Finally, historical research approaches largely excluded female participants and typically used very small sample sizes.
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Affiliation(s)
- Michael J McKenna
- Institute for Health and Sport, Victoria University, Melbourne, VIC, 8001, Australia.
- College of Physical Education, Southwest University, Chongqing, China.
- College of Sport Science, Zhuhai College of Science and Technology, Zhuhai, China.
| | - Jean-Marc Renaud
- Department of Cellular and Molecular Medicine, Neuromuscular Research Center, University of Ottawa, Ottawa, ON, Canada
| | - Niels Ørtenblad
- Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark
| | - Kristian Overgaard
- Exercise Biology, Department of Public Health, Aarhus University, Aarhus, Denmark
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Fernández-Sánchez J, Trujillo-Colmena D, Rodríguez-Castaño A, Lavín-Pérez AM, Del Coso J, Casado A, Collado-Mateo D. Effect of Acute Caffeine Intake on Fat Oxidation Rate during Fed-State Exercise: A Systematic Review and Meta-Analysis. Nutrients 2024; 16:207. [PMID: 38257100 PMCID: PMC10819049 DOI: 10.3390/nu16020207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 12/28/2023] [Accepted: 01/04/2024] [Indexed: 01/24/2024] Open
Abstract
Pre-exercise intake of caffeine (from ~3 to 9 mg/kg) has been demonstrated as an effective supplementation strategy to increase fat oxidation during fasted exercise. However, a pre-exercise meal can alter the potential effect of caffeine on fat oxidation during exercise as caffeine modifies postprandial glycaemic and insulinemic responses. Hypothetically, the effect of caffeine on fat oxidation may be reduced or even withdrawn during fed-state exercise. The present systematic review aimed to meta-analyse investigations on the effect of acute caffeine intake on the rate of fat oxidation during submaximal aerobic exercise performed in the fed state (last meal < 5 h before exercise). A total of 18 crossover trials with randomised and placebo-controlled protocols and published between 1982 and 2021 were included, with a total of 228 participants (185 males and 43 females). Data were extracted to compare rates of fat oxidation during exercise with placebo and caffeine at the same exercise intensity, which reported 20 placebo-caffeine pairwise comparisons. A meta-analysis of the studies was performed, using the standardised mean difference (SMD) estimated from Hedges' g, with 95% confidence intervals (CI). In comparison with the placebo, caffeine increased the rate of fat oxidation during fed-state exercise (number of comparisons (n) = 20; p = 0.020, SMD = 0.65, 95% CI = 0.20 to 1.20). Only studies with a dose < 6 mg/kg of caffeine (n = 13) increased the rate of fat oxidation during fed-state exercise (p = 0.004, SMD = 0.86, 95% CI = 0.27 to 1.45), while no such effect was observed in studies with doses ≥6 mg/kg (n = 7; p = 0.97, SMD = -0.03, 95% CI = -1.40 to 1.35). The effect of caffeine on fat oxidation during fed-state exercise was observed in active untrained individuals (n = 13; p < 0.001, SMD = 0.84, 95% CI = 0.39 to 1.30) but not in aerobically trained participants (n = 7; p = 0.27, SMD = 0.50, 95% CI = -0.39 to 1.39). Likewise, the effect of caffeine on fat oxidation was observed in caffeine-naïve participants (n = 9; p < 0.001, SMD = 0.82, 95% CI = 0.45 to 1.19) but not in caffeine consumers (n = 3; p = 0.54, SMD = 0.57, 95% CI = -1.23 to 2.37). In conclusion, acute caffeine intake in combination with a meal ingested within 5 h before the onset of exercise increased the rate of fat oxidation during submaximal aerobic exercise. The magnitude of the effect of caffeine on fat oxidation during fed-state exercise may be modulated by the dose of caffeine administered (higher with <6 mg/kg than with ≥6 mg/kg), participants' aerobic fitness level (higher in active than in aerobically trained individuals), and habituation to caffeine (higher in caffeine-naïve than in caffeine consumers).
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Affiliation(s)
- Javier Fernández-Sánchez
- Sport Sciences Research Centre, Rey Juan Carlos University, 28943 Madrid, Spain; (J.F.-S.); (D.T.-C.); (A.R.-C.); (A.C.); (D.C.-M.)
| | - Daniel Trujillo-Colmena
- Sport Sciences Research Centre, Rey Juan Carlos University, 28943 Madrid, Spain; (J.F.-S.); (D.T.-C.); (A.R.-C.); (A.C.); (D.C.-M.)
| | - Adrián Rodríguez-Castaño
- Sport Sciences Research Centre, Rey Juan Carlos University, 28943 Madrid, Spain; (J.F.-S.); (D.T.-C.); (A.R.-C.); (A.C.); (D.C.-M.)
| | - Ana Myriam Lavín-Pérez
- Sport Sciences Research Centre, Rey Juan Carlos University, 28943 Madrid, Spain; (J.F.-S.); (D.T.-C.); (A.R.-C.); (A.C.); (D.C.-M.)
- GO fitLAB, Ingesport, 28003 Madrid, Spain
| | - Juan Del Coso
- Sport Sciences Research Centre, Rey Juan Carlos University, 28943 Madrid, Spain; (J.F.-S.); (D.T.-C.); (A.R.-C.); (A.C.); (D.C.-M.)
| | - Arturo Casado
- Sport Sciences Research Centre, Rey Juan Carlos University, 28943 Madrid, Spain; (J.F.-S.); (D.T.-C.); (A.R.-C.); (A.C.); (D.C.-M.)
| | - Daniel Collado-Mateo
- Sport Sciences Research Centre, Rey Juan Carlos University, 28943 Madrid, Spain; (J.F.-S.); (D.T.-C.); (A.R.-C.); (A.C.); (D.C.-M.)
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Lowery LM, Anderson DE, Scanlon KF, Stack A, Escalante G, Campbell SC, Kerksick CM, Nelson MT, Ziegenfuss TN, VanDusseldorp TA, Kalman DS, Campbell BI, Kreider RB, Antonio J. International society of sports nutrition position stand: coffee and sports performance. J Int Soc Sports Nutr 2023; 20:2237952. [PMID: 37498180 PMCID: PMC10375938 DOI: 10.1080/15502783.2023.2237952] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 07/11/2023] [Indexed: 07/28/2023] Open
Abstract
Based on review and critical analysis of the literature regarding the contents and physiological effects of coffee related to physical and cognitive performance conducted by experts in the field and selected members of the International Society of Sports Nutrition (ISSN), the following conclusions represent the official Position of the Society:(1) Coffee is a complex matrix of hundreds of compounds. These are consumed with broad variability based upon serving size, bean type (e.g. common Arabica vs. Robusta), and brew method (water temperature, roasting method, grind size, time, and equipment).(2) Coffee's constituents, including but not limited to caffeine, have neuromuscular, antioxidant, endocrine, cognitive, and metabolic (e.g. glucose disposal and vasodilation) effects that impact exercise performance and recovery.(3) Coffee's physiologic effects are influenced by dose, timing, habituation to a small degree (to coffee or caffeine), nutrigenetics, and potentially by gut microbiota differences, sex, and training status.(4) Coffee and/or its components improve performance across a temporal range of activities from reaction time, through brief power exercises, and into the aerobic time frame in most but not all studies. These broad and varied effects have been demonstrated in men (mostly) and in women, with effects that can differ from caffeine ingestion, per se. More research is needed.(5) Optimal dosing and timing are approximately two to four cups (approximately 473-946 ml or 16-32 oz.) of typical hot-brewed or reconstituted instant coffee (depending on individual sensitivity and body size), providing a caffeine equivalent of 3-6 mg/kg (among other components such as chlorogenic acids at approximately 100-400 mg per cup) 60 min prior to exercise.(6) Coffee has a history of controversy regarding side effects but is generally considered safe and beneficial for healthy, exercising individuals in the dose range above.(7) Coffee can serve as a vehicle for other dietary supplements, and it can interact with nutrients in other foods.(8) A dearth of literature exists examining coffee-specific ergogenic and recovery effects, as well as variability in the operational definition of "coffee," making conclusions more challenging than when examining caffeine in its many other forms of delivery (capsules, energy drinks, "pre-workout" powders, gum, etc.).
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Affiliation(s)
- Lonnie M Lowery
- Walsh University, Department of Exercise Science, North Canton, OH, USA
- Nutrition, Exercise and Wellness Associates, Cuyahoga Falls, USA
| | - Dawn E Anderson
- Indiana Institute of Technology, Department of Biological and Physical Sciences, Fort Wayne, USA
| | - Kelsey F Scanlon
- Walsh University, Department of Exercise Science, North Canton, OH, USA
| | - Abigail Stack
- University of Mount Union, Department of Exercise, Nutrition, and Sport Science Alliance, USA
| | | | - Sara C Campbell
- The State University of New Jersey, Department of Kinesiology and Health, Rutgers, New Brunswick, USA
| | - Chad M Kerksick
- Lindenwood University, Exercise and Performance Nutrition Laboratory, St. Charles, USA
| | | | | | - Trisha A VanDusseldorp
- Bonafide Health, LLC p/b JDS Therapeutics, Harrison, USA
- Jacksonville University, Department of Health and Exercise Sciences, Jacksonville, USA
| | - Douglas S Kalman
- Nova Southeastern University, Department of Nutrition, College of Osteopathic Medicine, Fort Lauderdale, USA
| | - Bill I Campbell
- University of South Florida, Performance & Physique Enhancement Laboratory, Tampa, USA
| | - Richard B Kreider
- Texas A&M University, Exercise & Sport Nutrition Lab, Department of Kinesiology and Sports Management, College Station, USA
| | - Jose Antonio
- Nova Southeastern University, Department of Health and Human Performance, Davie, USA
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Abstract
Several pre-workout supplements contain niacin, although the exercise performance effects of niacin are poorly understood. The purpose of the present study was to examine the performance effects of niacin versus caffeine as a pre-workout supplement. Twenty-five untrained males were recruited to complete three identical ramped aerobic cycling exercise trials. Participants were administered caffeine (CA) at 5 mg/kg body weight, 1000 mg niacin (NI), or a methylcelluloce placebo (PL) supplement prior to each trial. NI treatment induced significantly higher respiratory exchange ratio (RER) during exercise compared to the CA treatment, but not the PL treatment (PL=0.87±0.08, NI=0.91±0.08, CA=0.87±0.08; p=0.02). Similarly, exercise time to exhaustion (in minutes) was significantly different between the NI treatment and the CA treatment, but not the PL treatment (PL=27.45±4.47, NI=26.30±4.91, CA=28.76±4.86; p<0.01). Habitual caffeine use (p=0.16), habitual aerobic exercise (p=0.60), and habitual resistance exercise (p=0.10) did not significantly affect RER. Similarly, habitual caffeine use (p=0.72), habitual aerobic exercise (p=0.08), and habitual resistance exercise (p=0.39) did not significantly affect total work performed. The elevated RER and decreased time to exhaustion in the NI treatment suggests limited lipid availability during exercise and impaired exercise performance.
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Gutiérrez-Hellín J, Aguilar-Navarro M, Ruiz-Moreno C, Muñoz A, Varillas-Delgado D, Amaro-Gahete FJ, Del Coso J. Effect of caffeine intake on fat oxidation rate during exercise: is there a dose-response effect? Eur J Nutr 2023; 62:311-319. [PMID: 35972531 DOI: 10.1007/s00394-022-02988-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 08/05/2022] [Indexed: 02/07/2023]
Abstract
PURPOSE The effect of caffeine to enhance fat utilisation as fuel for submaximal aerobic exercise is well established. However, it is unknown whether this effect is dose dependent. The aim of this study was to investigate the effect of 3 and 6 mg of caffeine per kg of body mass (mg/kg) on whole-body substrate oxidation during an incremental cycling exercise test. METHODS In a double-blind, randomised, and counterbalanced experiment, 18 recreationally active males (maximal oxygen uptake [VO2max] = 56.7 ± 8.2 mL/kg/min) performed three experimental trials after ingesting either 3 mg/kg of caffeine, 6 mg/kg of caffeine or a placebo (cellulose). The trials consisted of an incremental exercise test on a cycle ergometer with 3-min stages at workloads from 30 to 80% of VO2max. Energy expenditure, fat oxidation rate, and carbohydrate oxidation rate were continuously measured by indirect calorimetry. RESULTS During exercise, there was significant effect of substance (F = 7.969; P = 0.004) on fat oxidation rate. In comparison to the placebo, the rate of fat oxidation was higher with 3 mg/kg of caffeine at 30, 40, 50 and 70% of VO2max [all P < 0.050, effect sizes (ES) from 0.38 to 0.50] and with 6 mg/kg of caffeine at 30, 40, 50, 60 and 70% of VO2max (all P < 0.050, ES from 0.28 to 0.76). Both 3 mg/kg (0.40 ± 0.21 g/min, P = 0.021, ES = 0.57) and 6 mg/kg of caffeine (0.40 ± 0.17 g/min P = 0.001, ES = 0.60) increased the maximal rate of fat oxidation during exercise over the placebo (0.31 ± 0.15 g/min). None of the caffeine doses produced any significant effect on energy expenditure or heart rate during exercise, while both caffeine doses reduced perceived fatigue at 80% of VO2max (all P < 0.050, ES from 0.71 to 1.48). CONCLUSION The effect of caffeine to enhance fat oxidation during submaximal aerobic exercise is of similar magnitude with 3 and 6 mg of caffeine per kg of body mass. Thus, a dose of 3 mg of caffeine per kg of body mass would be sufficient to enhance fat utilisation as fuel during submaximal exercise.
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Affiliation(s)
- Jorge Gutiérrez-Hellín
- Faculty of Health Sciences, Universidad Francisco de Vitoria, Ctra. Pozuelo-Majadahonda KM 1.800, 28223, Pozuelo de Alarcón, Madrid, Spain
| | - Millán Aguilar-Navarro
- Faculty of Health Sciences, Universidad Francisco de Vitoria, Ctra. Pozuelo-Majadahonda KM 1.800, 28223, Pozuelo de Alarcón, Madrid, Spain.
| | - Carlos Ruiz-Moreno
- Excercise Physiology Laboratory, Camilo José Cela University, Madrid, Spain
| | - Alejandro Muñoz
- Faculty of Health Sciences, Universidad Francisco de Vitoria, Ctra. Pozuelo-Majadahonda KM 1.800, 28223, Pozuelo de Alarcón, Madrid, Spain
| | - David Varillas-Delgado
- Faculty of Health Sciences, Universidad Francisco de Vitoria, Ctra. Pozuelo-Majadahonda KM 1.800, 28223, Pozuelo de Alarcón, Madrid, Spain
| | | | - Juan Del Coso
- Centre for Sport Studies, Rey Juan Carlos University, Madrid, Spain
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Karayigit R, Forbes SC, Osmanov Z, Yilmaz C, Yasli BC, Naderi A, Buyukcelebi H, Benesova D, Gabrys T, Esen O. Low and Moderate Doses of Caffeinated Coffee Improve Repeated Sprint Performance in Female Team Sport Athletes. BIOLOGY 2022; 11:biology11101498. [PMID: 36290401 PMCID: PMC9598515 DOI: 10.3390/biology11101498] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 10/08/2022] [Accepted: 10/10/2022] [Indexed: 11/05/2022]
Abstract
The aim of this study was to determine the effect of low and moderate doses of caffeine ingestion via caffeinated coffee on repeated sprint test (RST) and plasma catecholamine concentration in trained female team-sport athletes. In a randomized, double-blind, crossover design, 13 female team-sport athletes (VO2max: 48.7 ± 4 mL·kg·min−1) completed three RST trials, separated by 4-day, 60 min post-ingestion of either 3 mg·kg−1 (LCOF) or 6 mg·kg−1 (MCOF) or placebo (PLA). The RST consisted of 12 × 4 s sprints on a cycle ergometer interspersed with 20 s of active recovery. Blood lactate (BLa) and glucose (GLU) and epinephrine and norepinephrine concentrations were collected before and 60 min after coffee ingestion, and after RST. Heart rate (HR) and ratings of perceived exertion (RPE) were measured at the beginning of RST, and after the 6th and 12th sprints. Average peak power score during RST was significantly improved after LCOF (p = 0.016) and MCOF (p = 0.041) compared to PLA, but peak and mean power output of the individual sprints, and fatigue index were not different between trials (all p > 0.05). Epinephrine and norepinephrine concentrations were significantly higher before and after RST in LCOF and MCOF compared to PLA (all p < 0.05). BLa was also higher after RST in both LCOF and MCOF compared to PLA (p = 0.005). HR, RPE, and GLU were not different between conditions (p > 0.05). In conclusion, low and moderate dose of caffeine ingestion can enhance the average peak power score during repeated sprints. These findings partly support low and moderate doses of caffeine supplementation via coffee as a nutritional ergogenic aid for trained female team-sport players during repeated sprint exercise.
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Affiliation(s)
- Raci Karayigit
- Faculty of Sport Sciences, Ankara University, Gölbaşı, Ankara 06830, Turkey
- Correspondence: ; Tel.: +90-312-600-0100
| | - Scott C. Forbes
- Department of Physical Education Studies, Brandon University, Brandon, MB R7A 6A9, Canada
| | - Zakir Osmanov
- Department of Medical Biochemistry, Faculty of Medicine, Gazi University, Ankara 06500, Turkey
| | - Canan Yilmaz
- Department of Medical Biochemistry, Faculty of Medicine, Gazi University, Ankara 06500, Turkey
| | - Burak Caglar Yasli
- Department of Coaching Education, Faculty of Sport Sciences, Iğdır University, Iğdır 76000, Turkey
| | - Alireza Naderi
- Department of Sport Physiology, Boroujerd Branch, Islamic Azad University, Boroujerd 6915136111, Iran
| | - Hakan Buyukcelebi
- Department of Coaching Education, Faculty of Sport Sciences, İnönü University, Malatya 44000, Turkey
| | - Daniela Benesova
- Department of Physical Education and Sport, Faculty of Education, University of West Bohemia, 30100 Pilsen, Czech Republic
| | - Tomasz Gabrys
- Department of Physical Education and Sport, Faculty of Education, University of West Bohemia, 30100 Pilsen, Czech Republic
| | - Ozcan Esen
- Department of Sport, Exercise and Rehabilitation, Northumbria University, Newcastle-upon-Tyne NE1 8ST, UK
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Panayi S, Galbraith A. Acute Ingestion of a Commercially Available Pre-workout Supplement Improves Anaerobic Power Output and Reduces Muscular Fatigue. INTERNATIONAL JOURNAL OF EXERCISE SCIENCE 2022; 15:455-472. [PMID: 35519437 PMCID: PMC9022706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The effect of a pre-workout supplement on anaerobic power output and muscular fatigue was examined. 18 participants took part in this double-blinded crossover study, reporting for testing on 3 occasions. Participants completed a 6×6 second repeated sprint test, with 20s recovery between sprints. Anaerobic power output was recorded as the highest power achieved during sprint test. Muscular fatigue was reported as a fatigue index across the six sprints ((maximum power - minimum power) ÷ total sprint time). During a baseline visit, participants consumed 250ml of water 30 minutes prior to testing, whilst in subsequent visits a taste-matched placebo (250ml water mixed with sugar-free juice) or a pre-workout supplement (250ml water mixed with one serving of 'THE PRE' myprotein.com). Anaerobic power output increased following pre-workout ingestion (pre-workout supplement, 885.8 ± 216.9W; Placebo, 853.6 ± 206.5W; Baseline, 839.3 ± 192.6W). Baseline vs pre-workout supplement (p = 0.01, g = 0.30); Placebo vs pre-workout supplement (p = 0.01, g = 0.20); Baseline vs Placebo (p = 0.59 g = 0.09). Muscular fatigue was reduced following pre-workout ingestion (Baseline, 4.92 ± 1.83W.s; Placebo, 4.39 ± 1.93W.s; pre-workout supplement, 3.31 ± 1.34W.s). Baseline vs pre-workout supplement (p = < 0.01 g = 0.98); Placebo vs pre-workout supplement (p = 0.01, g = 0.63); Baseline vs Placebo (p = 0.20, g = 0.28). Acute ingestion of a pre-workout supplement significantly improves anaerobic power output and attenuates muscular fatigue during repeated sprint cycling.
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Affiliation(s)
- Sotiris Panayi
- University of East London, Applied Sport Sciences Research Group, School of Health, Sport and Bioscience, Water Lane, Stratford, London, GREAT BRITTIAN
| | - Andy Galbraith
- University of East London, Applied Sport Sciences Research Group, School of Health, Sport and Bioscience, Water Lane, Stratford, London, GREAT BRITTIAN
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Effects of Caffeine and Caffeinated Beverages in Children, Adolescents and Young Adults: Short Review. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph182312389. [PMID: 34886115 PMCID: PMC8656548 DOI: 10.3390/ijerph182312389] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 11/20/2021] [Accepted: 11/22/2021] [Indexed: 12/03/2022]
Abstract
The prevalence of ED consumption has increased over the past 10–15 years. Studies describing the effects of caffeine and caffeinated beverages show confusing results, so it seems important to regularly summarize the available facts, and in more detail. By a thorough analysis of more than 156 scientific papers, the authors describe the molecular background of absorption, as well as the positive and negative effects of different dosages of caffeine, just like its effects in physical activity and performance. ED and EDwA consumption is a regular habit of not only adults, but nowadays even of children and adolescents. There are no safe dosages described of caffeine or ED consumption for children. There are no positive short- or long-term effects of these compounds/products concerning developing brain functions, psycho-motor functions, or social development. Instead, there are many unpleasant side effects, and symptoms of regular or higher-dose ED consumption, especially at younger ages. This mini review describes many details of these unpleasant side effects, their severity, and motivations for consuming these compounds/products. In a quantitative research in Hungary (10–26 years, mean age: 15.6 ± 3.8 y, 1459 subjects, randomly chosen population), a survey based on a questionnaire asking people about their ED consumption habits was conducted. According to the data, 81.8% of the participants consumed EDs at least once, and 63.3% tried several products of the kind. A positive correlation was found between age and consumption (p < 0.001). The results show that a high proportion of this group often consumed EDwA, in many cases leading to harmful side-effects of caffeine overdose. In a sample of Hungarian high school and college students (17–26 years), ED consumption matched the international data, and only 19.7% of respondents did not use EDs at all (had never tasted an ED in their life).
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Jones L, Johnstone I, Day C, Le Marquer S, Hulton AT. The Dose-Effects of Caffeine on Lower Body Maximal Strength, Muscular Endurance, and Rating of Perceived Exertion in Strength-Trained Females. Nutrients 2021; 13:3342. [PMID: 34684343 PMCID: PMC8539274 DOI: 10.3390/nu13103342] [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: 08/23/2021] [Revised: 09/21/2021] [Accepted: 09/21/2021] [Indexed: 01/22/2023] Open
Abstract
Caffeine supplementation has shown to be an effective ergogenic aid enhancing athletic performance, although limited research within female populations exists. Therefore, the aim of the investigation was to assess the effect of pre-exercise caffeine supplementation on strength performance and muscular endurance in strength-trained females. In a double-blind, randomised, counterbalanced design, fourteen strength-trained females using hormonal contraception consumed either 3 or 6 mg·kg-1 BM of caffeine or placebo (PLA). Following supplementation, participants performed a one-repetition maximum (1RM) leg press and repetitions to failure (RF) at 60% of their 1RM. During the RF test, rating of perceived exertion (RPE) was recorded every five repetitions and total volume (TV) lifted was calculated. Repeated measures ANOVA revealed that RF (p = 0.010) and TV (p = 0.012) attained significance, with pairwise comparisons indicating a significant difference between 3 mg·kg-1 BM and placebo for RF (p = 0.014), with an effect size of 0.56, and for 6 mg·kg-1 BM (p = 0.036) compared to the placebo, with an effect size of 0.65. No further significance was observed for 1RM or for RPE, and no difference was observed between caffeine trials. Although no impact on lower body muscular strength was observed, doses of 3 and 6 mg·kg-1 BM of caffeine improved lower body muscular endurance in resistance-trained females, which may have a practical application for enhancing resistance training stimuli and improving competitive performance.
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Affiliation(s)
| | | | | | | | - Andrew T. Hulton
- Department of Nutritional Sciences, Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7XH, UK; (L.J.); (I.J.); (C.D.); (S.L.M.)
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12
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Nicoll JX, Fry AC, Mosier EM. Androgen and glucocorticoid receptor phosphorylation following resistance exercise and pre-workout supplementation. Steroids 2021; 172:108859. [PMID: 33974920 DOI: 10.1016/j.steroids.2021.108859] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 03/05/2021] [Accepted: 04/24/2021] [Indexed: 11/17/2022]
Abstract
PURPOSE Consumption of caffeine or caffeine containing pre-workout supplements (SUPP) augments steroid hormone responses to resistance exercise (RE). However, the activation of glucocorticoid (GR) and androgen receptors (AR) following RE SUPP has not been investigated. The purpose of this study was to determine the influence of a pre-workout supplement on AR and GR phosphorylation following RE. METHODS In a randomized, counter-balanced, double-blind, placebo-controlled, within-subject crossover study, ten resistance-trained males ((X¯±SD, age = 22 ± 2.4 yrs, hgt = 175 ± 7 cm, body mass = 84.1 ± 11.8 kg) performed four sets of 8 repetitions of barbell back squats at 75% of their 1-repetition maximum (1-RM) with two minutes of rest between sets and a fifth set of barbell back squats at 60% of 1-RM until concentric failure. A SUPP or flavor and color matched placebo (PL) was consumed 60-minutes prior to RE. Vastus lateralis muscle biopsies were obtained prior to supplementation at rest (BL), and ten minutes post-exercise (POST). Biopsies were analyzed for phosphorylated GR (ser134, ser211, and ser226) and phosphorylated AR (ser81, ser213, ser515, ser650) via western blotting. RESULTS pGRser134 decreased, and pGRser226 increased following RE (p < 0.05) with no difference between conditions (p > 0.05). pGRser211 was unchanged after RE (p > 0.05). pARser515 increased, and total AR expression decreased after RE (p < 0.05) in SUPP only. Testosterone and cortisol were not different between SUPP and PL at POST (p > 0.05). CONCLUSION RE influences AR and GR phosphorylation, and SUPP minimally influences this response in the early recovery period.
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Affiliation(s)
- Justin X Nicoll
- California State University, Northridge, Department of Kinesiology, Northridge, CA, USA.
| | - Andrew C Fry
- University of Kansas, Department of Health, Sport, and Exercise Sciences, Lawrence, KS, USA.
| | - Eric M Mosier
- Northwest Missouri State University, School of Health Science and Wellness, Maryville, MO, USA.
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13
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Signals from the Circle: Tricarboxylic Acid Cycle Intermediates as Myometabokines. Metabolites 2021; 11:metabo11080474. [PMID: 34436415 PMCID: PMC8398969 DOI: 10.3390/metabo11080474] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 07/19/2021] [Accepted: 07/20/2021] [Indexed: 12/15/2022] Open
Abstract
Regular physical activity is an effective strategy to prevent and ameliorate aging-associated diseases. In particular, training increases muscle performance and improves whole-body metabolism. Since exercise affects the whole organism, it has countless health benefits. The systemic effects of exercise can, in part, be explained by communication between the contracting skeletal muscle and other organs and cell types. While small proteins and peptides known as myokines are the most prominent candidates to mediate this tissue cross-talk, recent investigations have paid increasing attention to metabolites. The purpose of this review is to highlight the potential role of tricarboxylic acid (TCA) metabolites as humoral mediators of exercise adaptation processes. We focus on TCA metabolites that are released from human skeletal muscle in response to exercise and provide an overview of their potential auto-, para- or endocrine health-promoting effects.
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14
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Hostrup M, Cairns SP, Bangsbo J. Muscle Ionic Shifts During Exercise: Implications for Fatigue and Exercise Performance. Compr Physiol 2021; 11:1895-1959. [PMID: 34190344 DOI: 10.1002/cphy.c190024] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Exercise causes major shifts in multiple ions (e.g., K+ , Na+ , H+ , lactate- , Ca2+ , and Cl- ) during muscle activity that contributes to development of muscle fatigue. Sarcolemmal processes can be impaired by the trans-sarcolemmal rundown of ion gradients for K+ , Na+ , and Ca2+ during fatiguing exercise, while changes in gradients for Cl- and Cl- conductance may exert either protective or detrimental effects on fatigue. Myocellular H+ accumulation may also contribute to fatigue development by lowering glycolytic rate and has been shown to act synergistically with inorganic phosphate (Pi) to compromise cross-bridge function. In addition, sarcoplasmic reticulum Ca2+ release function is severely affected by fatiguing exercise. Skeletal muscle has a multitude of ion transport systems that counter exercise-related ionic shifts of which the Na+ /K+ -ATPase is of major importance. Metabolic perturbations occurring during exercise can exacerbate trans-sarcolemmal ionic shifts, in particular for K+ and Cl- , respectively via metabolic regulation of the ATP-sensitive K+ channel (KATP ) and the chloride channel isoform 1 (ClC-1). Ion transport systems are highly adaptable to exercise training resulting in an enhanced ability to counter ionic disturbances to delay fatigue and improve exercise performance. In this article, we discuss (i) the ionic shifts occurring during exercise, (ii) the role of ion transport systems in skeletal muscle for ionic regulation, (iii) how ionic disturbances affect sarcolemmal processes and muscle fatigue, (iv) how metabolic perturbations exacerbate ionic shifts during exercise, and (v) how pharmacological manipulation and exercise training regulate ion transport systems to influence exercise performance in humans. © 2021 American Physiological Society. Compr Physiol 11:1895-1959, 2021.
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Affiliation(s)
- Morten Hostrup
- Section of Integrative Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Simeon Peter Cairns
- SPRINZ, School of Sport and Recreation, Auckland University of Technology, Auckland, New Zealand.,Health and Rehabilitation Research Institute, Auckland University of Technology, Auckland, New Zealand
| | - Jens Bangsbo
- Section of Integrative Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
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15
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Prado E, Magalhães-Neto A, Neto JR, Bassini A, Cameron LC. Caffeine decreases ammonemia in athletes using a ketogenic diet during prolonged exercise. Nutrition 2021; 91-92:111377. [PMID: 34273681 DOI: 10.1016/j.nut.2021.111377] [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: 11/02/2020] [Revised: 05/26/2021] [Accepted: 05/30/2021] [Indexed: 10/21/2022]
Abstract
OBJECTIVES Both exercise and a ketogenic (low-carbohydrate) diet favor glycogen depletion and increase ammonemia, which can impair physical performance. Caffeine supplementation has been routinely used to improve exercise performance. Herein, the effect of xanthine was evaluated on ammonemia in cyclists who were placed on a ketogenic diet and engaged in prolonged exercise. METHODS Fourteen male cyclists followed a ketogenic diet for 2 d before and during the experimental trial. The cyclists were assigned to either the caffeine- (CEx; n = 7) or placebo-supplemented (LEx; n = 7) group. Blood samples were obtained during cycling and the recovery periods. RESULTS The CEx group showed a significant decrease (up to 25%) in blood ammonia at 60, 90, and 120 min after beginning exercise compared with the LEx group. A higher concentration of apparent blood urea was observed in the LEx group than in the CEx group at 60 to 90 min of exercise (~10%). In addition, a significant increase in blood glucose levels was evident at 30 min of exercise (~28%), and an increase in blood lactate levels was visible during the first 30 to 60 min of exercise (~80%) in the CEx group. CONCLUSIONS Our results suggest that the consumption of caffeine might attenuate the increase in ammonemia that occurs during exercise.
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Affiliation(s)
- Eduardo Prado
- Laboratory for Research in Physical Exercise and Metabolism, Federal University of Alagoas, Maceió, Brazil
| | - Aníbal Magalhães-Neto
- Biological and Health Sciences Institute, Federal University of Mato Grosso, Barra do Garças, Brazil
| | - José Rezende Neto
- Department of Pharmacy, Federal University of Sergipe, Lagarto, Brazil
| | - Adriana Bassini
- Laboratory of Protein Biochemistry, Federal University of State of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Luiz-Claudio Cameron
- Laboratory of Protein Biochemistry, Federal University of State of Rio de Janeiro, Rio de Janeiro, Brazil.
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16
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Jessen S, Eibye K, Christensen PM, Hostrup M, Bangsbo J. No additive effect of acetaminophen when co-ingested with caffeine on cycling performance in well-trained young men. J Appl Physiol (1985) 2021; 131:238-249. [PMID: 34013747 DOI: 10.1152/japplphysiol.00108.2021] [Citation(s) in RCA: 3] [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
We investigated the effect of caffeine and acetaminophen on power output during a 6-min performance test, peripheral fatigue, and muscle protein kinase A (PKA) substrate phosphorylation. Fourteen men [age (means ± SD): 26 ± 6 yr; V̇o2max: 63.9 ± 5.0 mL·min-1·kg-1] completed four randomized trials with acetaminophen (1,500 mg), caffeine (5 mg·kg body wt-1), combined caffeine and acetaminophen (caffeine + acetaminophen), or placebo. Mean power output during the 6-min performance test (placebo mean: 312 ± 41 W) was higher with caffeine (+5 W; 95% CI: 1 to 9; P = 0.017) and caffeine + acetaminophen (+6 W; 95% CI: 0 to 12; P = 0.049) than placebo, but not with acetaminophen (+1 W; 95% CI: -4 to 7; P = 0.529). Decline in quadriceps maximal isometric voluntary torque immediately after the performance test was lower (treatment × time; P = 0.035) with acetaminophen (-40 N·m; 95% CI: -53 to -30; P < 0.001) and caffeine + acetaminophen (-44 N·m; 95% CI: -58 to -30; P < 0.001) than placebo (-53 N·m; 95% CI: -71 to -39; P < 0.001) but was similar with caffeine (-54 N·m; 95% CI: -69 to -38; P < 0.001). Muscle phosphocreatine content decreased more during the performance test (treatment × time; P = 0.036) with caffeine + acetaminophen (-55 mmol·kg dry wt-1; 95% CI: -65 to -46; P < 0.001) than placebo (-40 mmol·kg dry wt-1; 95% CI: -52 to -24; P < 0.001). Muscle net lactate accumulation was not different from placebo (+85 mmol·kg dry wt-1; 95% CI: 60 to 110; P < 0.001) for any treatment (treatment × time; P = 0.066), being +75 mmol·kg dry wt-1 (95% CI: 51 to 99; P < 0.001) with caffeine, +76 mmol·kg dry wt-1 (95% CI: 58 to 96; P < 0.001) with acetaminophen, and +103 mmol·kg dry wt-1 (95% CI: 89 to 115; P < 0.001) with caffeine + acetaminophen. Decline in muscle ATP and glycogen content and increase in PKA substrate phosphorylation was not different between treatments (treatment × time; P > 0.1). Thus, acetaminophen provides no additive performance enhancing effect to caffeine during 6-min maximal cycling. In addition, change in PKA activity is likely not a major mechanism of performance improvement with caffeine.NEW & NOTEWORTHY Here, we show that acetaminophen does not provide additive performance improvement to caffeine during a 6-min cycling ergometer performance test, and that acetaminophen does not improve performance on its own. Neither substance affects peripheral fatigue, muscle glycolytic energy production, or phosphorylation of muscle proteins of importance for ion handling. In contrast to previous suggestions, increased epinephrine action on muscle cells does not appear to be a major contributor to the performance enhancement with caffeine.
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Affiliation(s)
- Søren Jessen
- Section of Integrative Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Kasper Eibye
- Section of Integrative Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Peter Møller Christensen
- Section of Integrative Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark.,Team Danmark (Danish Elite Sports Organization), Copenhagen, Denmark
| | - Morten Hostrup
- Section of Integrative Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Jens Bangsbo
- Section of Integrative Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
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17
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Guest NS, VanDusseldorp TA, Nelson MT, Grgic J, Schoenfeld BJ, Jenkins NDM, Arent SM, Antonio J, Stout JR, Trexler ET, Smith-Ryan AE, Goldstein ER, Kalman DS, Campbell BI. International society of sports nutrition position stand: caffeine and exercise performance. J Int Soc Sports Nutr 2021; 18:1. [PMID: 33388079 PMCID: PMC7777221 DOI: 10.1186/s12970-020-00383-4] [Citation(s) in RCA: 193] [Impact Index Per Article: 64.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 10/31/2020] [Indexed: 12/13/2022] Open
Abstract
Following critical evaluation of the available literature to date, The International Society of Sports Nutrition (ISSN) position regarding caffeine intake is as follows: 1. Supplementation with caffeine has been shown to acutely enhance various aspects of exercise performance in many but not all studies. Small to moderate benefits of caffeine use include, but are not limited to: muscular endurance, movement velocity and muscular strength, sprinting, jumping, and throwing performance, as well as a wide range of aerobic and anaerobic sport-specific actions. 2. Aerobic endurance appears to be the form of exercise with the most consistent moderate-to-large benefits from caffeine use, although the magnitude of its effects differs between individuals. 3. Caffeine has consistently been shown to improve exercise performance when consumed in doses of 3-6 mg/kg body mass. Minimal effective doses of caffeine currently remain unclear but they may be as low as 2 mg/kg body mass. Very high doses of caffeine (e.g. 9 mg/kg) are associated with a high incidence of side-effects and do not seem to be required to elicit an ergogenic effect. 4. The most commonly used timing of caffeine supplementation is 60 min pre-exercise. Optimal timing of caffeine ingestion likely depends on the source of caffeine. For example, as compared to caffeine capsules, caffeine chewing gums may require a shorter waiting time from consumption to the start of the exercise session. 5. Caffeine appears to improve physical performance in both trained and untrained individuals. 6. Inter-individual differences in sport and exercise performance as well as adverse effects on sleep or feelings of anxiety following caffeine ingestion may be attributed to genetic variation associated with caffeine metabolism, and physical and psychological response. Other factors such as habitual caffeine intake also may play a role in between-individual response variation. 7. Caffeine has been shown to be ergogenic for cognitive function, including attention and vigilance, in most individuals. 8. Caffeine may improve cognitive and physical performance in some individuals under conditions of sleep deprivation. 9. The use of caffeine in conjunction with endurance exercise in the heat and at altitude is well supported when dosages range from 3 to 6 mg/kg and 4-6 mg/kg, respectively. 10. Alternative sources of caffeine such as caffeinated chewing gum, mouth rinses, energy gels and chews have been shown to improve performance, primarily in aerobic exercise. 11. Energy drinks and pre-workout supplements containing caffeine have been demonstrated to enhance both anaerobic and aerobic performance.
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Affiliation(s)
- Nanci S Guest
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, 1 King's College Circle, Room 5326A, Toronto, ON, M5S 1A8, Canada.
| | - Trisha A VanDusseldorp
- Department of Exercise Science and Sport Management, Kennesaw State University, Kennesaw, GA, 30144, USA
| | | | - Jozo Grgic
- Institute for Health and Sport (IHES), Victoria University, Melbourne, Australia
| | - Brad J Schoenfeld
- Department of Health Sciences, CUNY Lehman College, Bronx, NY, 10468, USA
| | - Nathaniel D M Jenkins
- Department of Health and Human Physiology, University of Iowa, Iowa City, IA, 52240, USA
| | - Shawn M Arent
- Department of Exercise Science, Arnold School of Public Health, University of South Carolina, Colombia, SC, 29208, USA
- School of Social and Health Sciences, Leeds Trinity University, Leeds, UK
| | - Jose Antonio
- Exercise and Sport Science, Nova Southeastern University, Davie, FL, 33314, USA
| | - Jeffrey R Stout
- Institue of Exercise Physiology and Rehabilitation Science, University of Central Florida, Orlando, FL, 32816, USA
| | | | - Abbie E Smith-Ryan
- Department of Exercise and Sport Science, Applied Physiology Laboratory, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Erica R Goldstein
- Institue of Exercise Physiology and Rehabilitation Science, University of Central Florida, Orlando, FL, 32816, USA
| | - Douglas S Kalman
- Nutrion Department, College of Osteopathic Medicine, Nova Southeastern University, Fort Lauderdale, FL, 33314, USA
- Scientific Affairs. Nutrasource, Guelph, ON, Canada
| | - Bill I Campbell
- Performance & Physique Enhancement Laboratory, University of South Florida, Tampa, FL, 33612, USA
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18
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Collado-Mateo D, Lavín-Pérez AM, Merellano-Navarro E, Coso JD. Effect of Acute Caffeine Intake on the Fat Oxidation Rate during Exercise: A Systematic Review and Meta-Analysis. Nutrients 2020; 12:nu12123603. [PMID: 33255240 PMCID: PMC7760526 DOI: 10.3390/nu12123603] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 11/17/2020] [Accepted: 11/20/2020] [Indexed: 12/30/2022] Open
Abstract
A number of previous investigations have been designed to determine the effect of acute caffeine intake on the rate of fat oxidation during exercise. However, these investigations have shown contradictory results due to the differences in the exercise protocols used or the co-ingestion of caffeine with other substances. Hence, to date, there is no consensus about the effect of caffeine on fat oxidation during exercise. The purpose of this study was to conduct a systematic review followed by a meta-analysis to establish the effect of acute intake of caffeine (ranging from 2 to 7 mg/kg of body mass) on the rate of fat oxidation during exercise. A total of 19 studies published between 1978 and 2020 were included, all of which employed crossover experimental designs in which the ingestion of caffeine was compared to a placebo. Studies were selected if the exercise intensity was consistent in the caffeine and placebo trials and if these were preceded by a fasting protocol. A subsequent meta-analysis was performed using the random effects model to calculate the standardized mean difference (SMD). The meta-analysis revealed that caffeine significantly (p = 0.008) increased the fat oxidation rate (SMD = 0.73; 95% CI = 0.19 to 1.27). This increment was consistent with a significant (p = 0.04) reduction of the respiratory exchange ratio (SMD = -0.33; 95% CI = -0.65 to -0.01) and a significant (p = 0.049) increase in the oxygen uptake (SMD = 0.23; 95% CI = 0.01 to 0.44). The results also showed that there was a dose-response effect of caffeine on the fat oxidation rate, indicating that more than 3.0 mg/kg is necessary to obtain a statistically significant effect of this stimulant on fat oxidation during exercise. Additionally, the ability of caffeine to enhance fat oxidation during exercise was higher in sedentary or untrained individuals than in trained and recreational athletes. In conclusion, pre-exercise intake of a moderate dose of caffeine may effectively increase fat utilization during aerobic exercise of submaximal intensity performed after a fasting period. However, the fitness level of the participant may modulate the magnitude of the effect of caffeine on fat oxidation during exercise.
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Affiliation(s)
- Daniel Collado-Mateo
- Centre for Sport Studies, Rey Juan Carlos University, 28043 Fuenlabrada, Spain; (D.C.-M.); (A.M.L.-P.)
| | - Ana Myriam Lavín-Pérez
- Centre for Sport Studies, Rey Juan Carlos University, 28043 Fuenlabrada, Spain; (D.C.-M.); (A.M.L.-P.)
- GO fit LAB, Ingesport, 28003 Madrid, Spain
| | | | - Juan Del Coso
- Centre for Sport Studies, Rey Juan Carlos University, 28043 Fuenlabrada, Spain; (D.C.-M.); (A.M.L.-P.)
- Correspondence:
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19
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Ruiz-Moreno C, Gutiérrez-Hellín J, Amaro-Gahete FJ, González-García J, Giráldez-Costas V, Pérez-García V, Del Coso J. Caffeine increases whole-body fat oxidation during 1 h of cycling at Fatmax. Eur J Nutr 2020; 60:2077-2085. [PMID: 33025051 DOI: 10.1007/s00394-020-02393-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 09/21/2020] [Indexed: 12/21/2022]
Abstract
PURPOSE The ergogenic effect of caffeine on exercise of maximum intensity has been well established. However, there is controversy regarding the effect of caffeine on shifting substrate oxidation at submaximal exercise. The aim of this study was to investigate the effect of acute caffeine ingestion on whole-body substrate oxidation during 1 h of cycling at the intensity that elicits maximal fat oxidation (Fatmax). METHODS In a double-blind, randomized, and counterbalanced experiment, 12 healthy participants (VO2max = 50.7 ± 12.1 mL/kg/min) performed two acute experimental trials after ingesting either caffeine (3 mg/kg) or a placebo (cellulose). The trials consisted of 1 h of continuous cycling at Fatmax. Energy expenditure, fat oxidation rate, and carbohydrate oxidation rate were continuously measured by indirect calorimetry. RESULTS In comparison to the placebo, caffeine increased the amount of fat oxidized during the trial (19.4 ± 7.7 vs 24.7 ± 9.6 g, respectively; P = 0.04) and decreased the amount of carbohydrate oxidized (94.6 ± 30.9 vs 73.8 ± 32.4 g; P = 0.01) and the mean self-perception of fatigue (Borg scale = 11 ± 2 vs 10 ± 2 arbitrary units; P = 0.05). In contrast, caffeine did not modify total energy expenditure (placebo = 543 ± 175; caffeine = 559 ± 170 kcal; P = 0.60) or mean heart rate (125 ± 13 and 127 ± 9 beats/min; P = 0.30) during exercise. Before exercise, caffeine increased systolic and diastolic blood pressure whilst it increased the feelings of nervousness and vigour after exercise (P < 0.05). CONCLUSION These results suggest that a moderate dose of caffeine (3 mg/kg) increases the amount of fat oxidized during 1 h of cycling at Fatmax. Thus, caffeine might be used as an effective strategy to enhance body fat utilization during submaximal exercise. The occurrence of several side effects should be taken into account when using caffeine to reduce body fat in populations with hypertension or high sensitivity to caffeine.
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Affiliation(s)
- Carlos Ruiz-Moreno
- Exercise Physiology Laboratory, Camilo José Cela University, Madrid, Spain
| | | | | | | | - Verónica Giráldez-Costas
- Exercise Physiology Laboratory, Camilo José Cela University, Madrid, Spain.,Department of Physical Education, Sport and Human Movement, Autonomus University of Madrid, Madrid, Spain
| | | | - Juan Del Coso
- Centre for Sport Studies, Rey Juan Carlos University, Camino del Molino, s/n, 28943, Fuenlabrada, Spain.
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20
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Hargreaves M, Spriet LL. Skeletal muscle energy metabolism during exercise. Nat Metab 2020; 2:817-828. [PMID: 32747792 DOI: 10.1038/s42255-020-0251-4] [Citation(s) in RCA: 411] [Impact Index Per Article: 102.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 06/25/2020] [Indexed: 12/12/2022]
Abstract
The continual supply of ATP to the fundamental cellular processes that underpin skeletal muscle contraction during exercise is essential for sports performance in events lasting seconds to several hours. Because the muscle stores of ATP are small, metabolic pathways must be activated to maintain the required rates of ATP resynthesis. These pathways include phosphocreatine and muscle glycogen breakdown, thus enabling substrate-level phosphorylation ('anaerobic') and oxidative phosphorylation by using reducing equivalents from carbohydrate and fat metabolism ('aerobic'). The relative contribution of these metabolic pathways is primarily determined by the intensity and duration of exercise. For most events at the Olympics, carbohydrate is the primary fuel for anaerobic and aerobic metabolism. Here, we provide an overview of exercise metabolism and the key regulatory mechanisms ensuring that ATP resynthesis is closely matched to the ATP demand of exercise. We also summarize various interventions that target muscle metabolism for ergogenic benefit in athletic events.
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Affiliation(s)
- Mark Hargreaves
- Department of Physiology, University of Melbourne, Melbourne, Victoria, Australia.
| | - Lawrence L Spriet
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada.
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21
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Caffeine effects on systemic metabolism, oxidative-inflammatory pathways, and exercise performance. Nutr Res 2020; 80:1-17. [DOI: 10.1016/j.nutres.2020.05.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 04/11/2020] [Accepted: 05/09/2020] [Indexed: 01/06/2023]
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Fogaça LJ, Santos SL, Soares RC, Gentil P, Naves JP, dos Santos WD, Pimentel GD, Bottaro M, Mota JF. Effect of caffeine supplementation on exercise performance, power, markers of muscle damage, and perceived exertion in trained CrossFit men: a randomized, double-blind, placebo-controlled crossover trial. J Sports Med Phys Fitness 2020; 60:181-188. [DOI: 10.23736/s0022-4707.19.10043-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Clark NW, Wells AJ, Coker NA, Goldstein ER, Herring CH, Starling-Smith TM, Varanoske AN, Panissa VLG, Stout JR, Fukuda DH. The acute effects of thermogenic fitness drink formulas containing 140 mg and 100 mg of caffeine on energy expenditure and fat metabolism at rest and during exercise. J Int Soc Sports Nutr 2020; 17:10. [PMID: 32054486 PMCID: PMC7020555 DOI: 10.1186/s12970-020-0341-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 01/30/2020] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Thermogenic fitness drink formulas (TFD) have been shown to increase energy expenditure and markers of lipid metabolism. The purpose of the current study was to compare TFD formulas containing different caffeine concentrations versus a placebo drink on energy expenditure and lipid metabolism at rest and during exercise. METHODS Thirty-two recreationally active participants (22.9 ± 0.7 y, 167.1 ± 1.4 cm, 68.8 ± 2.0 kg, 24.0 ± 1.2% fat) who were regular caffeine consumers, participated in this randomized, double-blind, crossover design study. Participants reported to the laboratory on three occasions, each of which required consumption of either a TFD containing 140 mg or 100 mg of caffeine or a placebo. Baseline measurements of resting energy expenditure (REE) and resting fat oxidation (RFO) were assessed using indirect calorimetry as well as measurements of serum glycerol concentration. Measurements were repeated at 30, 60, 90 min post-ingestion. Following resting measures, participants completed a graded exercise test to determine maximal oxygen uptake (V̇O2max), maximal fat oxidation (MFO) and the exercise intensity that elicits MFO (Fatmax), and total energy expenditure (EE). RESULTS A significant interaction was shown for REE (p < 0.01) and RFO (p < 0.01). Area under the curve analysis showed an increased REE for the 140 mg compared to the 100 mg formula (p = 0.02) and placebo (p < 0.01) and an increased REE for the 100 mg formula compared to placebo (p = 0.02). RFO significantly decreased for caffeinated formulas at 30 min post ingestion compared to placebo and baseline (p < 0.01) and significantly increased for the 140 mg formula at 60 min post-ingestion (p = 0.03). A main effect was shown for serum glycerol concentrations over time (p < 0.01). No significant differences were shown for V̇O2max (p = 0.12), Fatmax (p = 0.22), and MFO (p = 0.05), and EE (p = 0.08) across drinks. CONCLUSIONS Our results suggest that TFD formulas containing 100 and 140 mg of caffeine are effective in increasing REE and that a 40 mg of caffeine difference between the tested formulas may impact REE and RFO in healthy individuals within 60 min of ingestion.
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Affiliation(s)
- Nicolas W Clark
- School of Kinesiology and Physical Therapy, Institute of Exercise Physiology and Rehabilitation Science, University of Central Florida, Orlando, Florida, USA
| | - Adam J Wells
- School of Kinesiology and Physical Therapy, Institute of Exercise Physiology and Rehabilitation Science, University of Central Florida, Orlando, Florida, USA
| | - Nicholas A Coker
- School of Kinesiology and Physical Therapy, Institute of Exercise Physiology and Rehabilitation Science, University of Central Florida, Orlando, Florida, USA
| | - Erica R Goldstein
- School of Kinesiology and Physical Therapy, Institute of Exercise Physiology and Rehabilitation Science, University of Central Florida, Orlando, Florida, USA
| | - Chad H Herring
- School of Kinesiology and Physical Therapy, Institute of Exercise Physiology and Rehabilitation Science, University of Central Florida, Orlando, Florida, USA
| | - Tristan M Starling-Smith
- School of Kinesiology and Physical Therapy, Institute of Exercise Physiology and Rehabilitation Science, University of Central Florida, Orlando, Florida, USA
| | - Alyssa N Varanoske
- School of Kinesiology and Physical Therapy, Institute of Exercise Physiology and Rehabilitation Science, University of Central Florida, Orlando, Florida, USA
| | - Valeria L G Panissa
- Department of Sport, School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil
| | - Jeffrey R Stout
- School of Kinesiology and Physical Therapy, Institute of Exercise Physiology and Rehabilitation Science, University of Central Florida, Orlando, Florida, USA
| | - David H Fukuda
- School of Kinesiology and Physical Therapy, Institute of Exercise Physiology and Rehabilitation Science, University of Central Florida, Orlando, Florida, USA.
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Reggiani C. Caffeine as a tool to investigate sarcoplasmic reticulum and intracellular calcium dynamics in human skeletal muscles. J Muscle Res Cell Motil 2020; 42:281-289. [PMID: 32034582 DOI: 10.1007/s10974-020-09574-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 01/30/2020] [Indexed: 12/23/2022]
Abstract
Caffeine is worldwide used for its power to increase cognitive and physical performance. The ergogenic effects of caffeine, however, do not depend on a direct action on muscles. Actually, the actions of caffeine on skeletal muscles, take place at millimolar concentrations which are far above the micromolar level reached after a regular consumption of coffee or similar drinks, and close to a lethal concentration. At millimolar concentrations caffeine exerts a powerful effect on sarcoplasmic reticulum (SR) activating the release of calcium via ryanodine receptors and, possibly, inhibiting calcium reuptake. For this reason caffeine has become a valuable tool for studying SR function and for diagnostics of SR related muscle disorders. This review aims to briefly describe the effects and the mechanism of action of caffeine on sarcoplasmic reticulum and to focus on its use to study intracellular calcium dynamics in human muscle fibers in physiological and pathological conditions.
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Affiliation(s)
- Carlo Reggiani
- Department of Biomedical Sciences, University of Padova, Via Marzolo 3, 35131, Padua, Italy. .,ZRS-Science and Research Center, Koper, Slovenia.
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25
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Zhu M, Zhu H, Ding X, Liu S, Zou Y. Analysis of the anti-fatigue activity of polysaccharides from Spirulina platensis: role of central 5-hydroxytryptamine mechanisms. Food Funct 2020; 11:1826-1834. [PMID: 32057057 DOI: 10.1039/c9fo02804h] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This study evaluated the effects of polysaccharides from Spirulina platensis (PSP) on endurance during treadmill exercise; levels of some biochemical indicators and expressions of serotonin related genes in the caudate putamen of exercising rats.
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Affiliation(s)
- Meiju Zhu
- School of Sports Science
- Jinggangshan University
- Jian 343009
- China
| | - Hongzhu Zhu
- School of Sports Science
- Jinggangshan University
- Jian 343009
- China
| | - Xiaomin Ding
- School of Sports Science
- Jinggangshan University
- Jian 343009
- China
| | - Shaosheng Liu
- School of Sports Science
- Jinggangshan University
- Jian 343009
- China
| | - Yuanhua Zou
- The Affiliated Hospital
- Jinggangshan University
- Jian 343009
- China
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26
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Chia JS, Barrett LA, Chow JY, Burns SF. Effects of Caffeine Supplementation on Performance in Ball Games. Sports Med 2018; 47:2453-2471. [PMID: 28741186 DOI: 10.1007/s40279-017-0763-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Although a large body of evidence exists documenting the ergogenic properties of caffeine, most studies have focused on endurance performance. However, findings from endurance sports cannot be generalized to performance in ball games where, apart from having a high level of endurance, successful athletic performances require a combination of physiological, technical and cognitive capabilities. The purpose of this review was to critically evaluate studies that have examined the effect of a single dose of caffeine in isolation on one or more of the following performance measures: total distance, sprint performance, agility, vertical jump performance and accuracy in ball games. Searches of three major databases resulted in 19 studies (invasion games: 13; net-barrier games: 6) that evaluated the acute effects of caffeine on human participants, provided the caffeine dose administered, and included a ball games specific task or simulated match. Improvements in sprint performance were observed in 8 of 10 studies (80%), and vertical jump in 7 of 8 studies (88%). Equivocal results were reported for distance covered, agility and accuracy. Minor side effects were reported in 4 of 19 studies reviewed. Pre-exercise caffeine ingestion between 3.0 and 6.0 mg/kg of body mass appears to be a safe ergogenic aid for athletes in ball games. However, the efficacy of caffeine varies depending on various factors, including, but not limited to, the nature of the game, physical status and caffeine habituation. More research is warranted to clarify the effects of caffeine on performance measures unique to ball games, such as agility and accuracy. It is essential that athletes, coaches and practitioners evaluate the risk-benefit ratio of caffeine ingestion strategies on an individual case-by-case basis.
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Affiliation(s)
- Jingyi Shannon Chia
- Physical Education and Sports Science, National Institute of Education, Nanyang Technological University, 1 Nanyang Walk, Singapore, 637616, Singapore
- Institute for Sports Research, Nanyang Technological University, Singapore, Singapore
- School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
| | - Laura Ann Barrett
- School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
| | - Jia Yi Chow
- Physical Education and Sports Science, National Institute of Education, Nanyang Technological University, 1 Nanyang Walk, Singapore, 637616, Singapore
| | - Stephen Francis Burns
- Physical Education and Sports Science, National Institute of Education, Nanyang Technological University, 1 Nanyang Walk, Singapore, 637616, Singapore.
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Southward K, Rutherfurd-Markwick K, Badenhorst C, Ali A. The Role of Genetics in Moderating the Inter-Individual Differences in the Ergogenicity of Caffeine. Nutrients 2018; 10:E1352. [PMID: 30248915 PMCID: PMC6213712 DOI: 10.3390/nu10101352] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 09/10/2018] [Accepted: 09/17/2018] [Indexed: 12/17/2022] Open
Abstract
Caffeine use is widespread among athletes following its removal from the World Anti-Doping Agency banned list, with approximately 75% of competitive athletes using caffeine. While literature supports that caffeine has a small positive ergogenic effect for most forms of sports and exercise, there exists a significant amount of inter-individual difference in the response to caffeine ingestion and the subsequent effect on exercise performance. In this narrative review, we discuss some of the potential mechanisms and focus on the role that genetics has in these differences. CYP1A2 and ADORA2A are two of the genes which are thought to have the largest impact on the ergogenicity of caffeine. CYP1A2 is responsible for the majority of the metabolism of caffeine, and ADORA2A has been linked to caffeine-induced anxiety. The effects of CYP1A2 and ADORA2A genes on responses to caffeine will be discussed in detail and an overview of the current literature will be presented. The role of these two genes may explain a large portion of the inter-individual variance reported by studies following caffeine ingestion. Elucidating the extent to which these genes moderate responses to caffeine during exercise will ensure caffeine supplementation programs can be tailored to individual athletes in order to maximize the potential ergogenic effect.
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Affiliation(s)
- Kyle Southward
- School of Sport, Exercise and Nutrition, Massey University, North Shore Mail Centre, Private Bag 102 904, Auckland 0745, New Zealand.
| | - Kay Rutherfurd-Markwick
- School of Health Sciences, Massey University, Auckland 0745, New Zealand.
- Centre for Metabolic Health Research, Massey University, Auckland 0745, New Zealand.
| | - Claire Badenhorst
- School of Sport, Exercise and Nutrition, Massey University, North Shore Mail Centre, Private Bag 102 904, Auckland 0745, New Zealand.
- Centre for Metabolic Health Research, Massey University, Auckland 0745, New Zealand.
| | - Ajmol Ali
- School of Sport, Exercise and Nutrition, Massey University, North Shore Mail Centre, Private Bag 102 904, Auckland 0745, New Zealand.
- Centre for Metabolic Health Research, Massey University, Auckland 0745, New Zealand.
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Lopes-Silva JP, Santos JFDS, Franchini E. Can caffeine supplementation reverse the effect of time of day on repeated-sprint exercise performance? Appl Physiol Nutr Metab 2018; 44:187-193. [PMID: 30058345 DOI: 10.1139/apnm-2018-0373] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The aim of this study was to evaluate if caffeine can reduce the negative influence of diurnal variations on repeated-sprint performance, in addition to investigating if caffeine in the afternoon would potentiate performance compared with the morning. Thirteen physically active men took part in this randomized, double-blind, placebo-controlled and crossover study. All participants underwent a repeated-sprint ability test (10 × 6 s cycle sprints, with 30 s of rest) at 60 min after ingestion of either 5 mg·kg-1 or placebo under 4 different conditions: morning with caffeine ingestion, morning with placebo ingestion, afternoon with caffeine ingestion, and afternoon with placebo ingestion. Total work, peak power (PP) and anaerobic power reserve (APR) were assessed. Oxygen uptake, heart rate, lactate concentration, and rating of perceived exertion were also measured during the repeated-sprint test. Total work (+8%, d = 0.2, small), PP (+6%, d = 0.2), and APR (+9%, d = 0.2) were significantly higher in the afternoon when compared with morning. However, physiological responses were not different between caffeine and placebo conditions. Repeated-sprint (10 × 6 s cycle sprint) performance was influenced by time of day, with lower performance in the morning compared with the afternoon. However, caffeine supplementation did not prevent the reduction in performance in the morning or improve performance in the afternoon.
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Affiliation(s)
- João Paulo Lopes-Silva
- a High-Intensity Intermittent Exercise Physiology Research Group, School of Physical and Education and Sport, University of São Paulo, São Paulo 05508-030, Brazil.,b School of Physical Education, University Center Cesmac, Maceió, Alagoas, 57051-530, Brazil
| | - Jonatas Ferreira da Silva Santos
- a High-Intensity Intermittent Exercise Physiology Research Group, School of Physical and Education and Sport, University of São Paulo, São Paulo 05508-030, Brazil.,c Physical Education Department, Health and Biological Science Faculty, Federal University of the Jequitinhonha and Mucuri Valleys, Diamantina - Minas Gerais 39803-371, Brazil
| | - Emerson Franchini
- a High-Intensity Intermittent Exercise Physiology Research Group, School of Physical and Education and Sport, University of São Paulo, São Paulo 05508-030, Brazil.,d Combat Centre, Australian Institute of Sport, Canberra, Australia
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Oskarsson J, McGawley K. No individual or combined effects of caffeine and beetroot-juice supplementation during submaximal or maximal running. Appl Physiol Nutr Metab 2018; 43:697-703. [DOI: 10.1139/apnm-2017-0547] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Dietary supplements such as caffeine and beetroot juice are used by athletes in an attempt to optimize performance and therefore gain an advantage in competition. The aim of this study was to investigate the individual and combined effects of caffeine and beetroot-juice supplementation during submaximal and maximal treadmill running. Seven males (maximal oxygen uptake: 59.0 ± 2.9 mL·kg–1·min–1) and 2 females (maximal oxygen uptake: 53.1 ± 11.4 mL·kg–1·min–1) performed a preliminary trial followed by 4 experimental test sessions. Each test session consisted of two 5-min submaximal running bouts (at ∼70% and 80% of maximal oxygen uptake) and a maximal 1-km time trial (TT) in a laboratory. Participants ingested 70 mL of concentrated beetroot juice containing either 7.3 mmol of nitrate (BR) or no nitrate (PBR) 2.5 h prior to each test session, then either caffeine (C) at 4.8 ± 0.4 (4.3–5.6) mg/kg of body mass or a caffeine placebo (PC) 45 min before each test session. The 4 test sessions (BR-C, BR-PC, PBR-C, and PBR-PC) were presented in a counterbalanced and double-blind manner. No significant differences were identified between the 4 interventions regarding relative oxygen uptake, running economy, respiratory exchange ratio, heart rate (HR), or rating of perceived exertion (RPE) at the 2 submaximal intensities (P > 0.05). Moreover, there were no significant differences in performance, maximum HR, peak blood lactate concentration, or RPE during the maximal TT when comparing the interventions (P > 0.05). In conclusion, no beneficial effects of supplementing with typical doses of caffeine, beetroot juice, or a combination of the two were observed for physiological, perceptual, or performance responses during submaximal or maximal treadmill running exercise.
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Affiliation(s)
- Johanna Oskarsson
- Swedish Winter Sports Research Centre, Department of Health Sciences, Mid Sweden University, 831 25 Östersund, Sweden
- Swedish Winter Sports Research Centre, Department of Health Sciences, Mid Sweden University, 831 25 Östersund, Sweden
| | - Kerry McGawley
- Swedish Winter Sports Research Centre, Department of Health Sciences, Mid Sweden University, 831 25 Östersund, Sweden
- Swedish Winter Sports Research Centre, Department of Health Sciences, Mid Sweden University, 831 25 Östersund, Sweden
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Caffeine and Physiological Responses to Submaximal Exercise: A Meta-Analysis. Int J Sports Physiol Perform 2018; 13:402-411. [PMID: 28872376 DOI: 10.1123/ijspp.2017-0312] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The aim of this study was to carry out a systematic review and meta-analysis of the effects of caffeine supplementation on physiological responses to submaximal exercise. A total of 26 studies met the inclusion criteria of adopting double-blind, randomized crossover designs that included a sustained (5-30 min) fixed-intensity bout of submaximal exercise (constrained to 60-85% maximal rate of oxygen consumption) using a standard caffeine dose of 3-6 mg·kg-1 administered 30-90 min prior to exercise. Meta-analyses were completed using a random-effects model, and data are presented as raw mean difference (D) with associated 95% confidence limits (CLs). Relative to placebo, caffeine led to significant increases in submaximal measures of minute ventilation (D = 3.36 L·min-1; 95% CL, 1.63-5.08; P = .0001; n = 73), blood lactate (D = 0.69 mmol·L-1; 95% CL, 0.46-0.93; P < .00001; n = 208), and blood glucose (D = 0.42 mmol·L-1; 95% CL, 0.29-0.55; P < .00001; n = 129). In contrast, caffeine had a suppressive effect on ratings of perceived exertion (D = -0.8; 95% CL, -1.1 to -0.6; P < .00001; n = 147). Caffeine had no effect on measures of heart rate (P = .99; n = 207), respiratory exchange ratio (P = .18; n = 181), or oxygen consumption (P = .92; n = 203). The positive effects of caffeine supplementation on sustained high-intensity exercise performance are widely accepted, although the mechanisms to explain that response are currently unresolved. This meta-analysis has revealed clear effects of caffeine on various physiological responses during submaximal exercise, which may help explain its ergogenic action.
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Carlström M, Larsson SC. Coffee consumption and reduced risk of developing type 2 diabetes: a systematic review with meta-analysis. Nutr Rev 2018; 76:395-417. [DOI: 10.1093/nutrit/nuy014] [Citation(s) in RCA: 108] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Affiliation(s)
- Mattias Carlström
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Susanna C Larsson
- Unit of Nutritional Epidemiology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
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Graham-Paulson TS, Paulson TAW, Perret C, Tolfrey K, Cordery P, Goosey-Tolfrey VL. Spinal Cord Injury Level Influences Acute Plasma Caffeine Responses. Med Sci Sports Exerc 2017; 49:363-370. [PMID: 27669443 DOI: 10.1249/mss.0000000000001108] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE This study aimed to investigate the absorption curve and acute effects of caffeine at rest in individuals with no spinal cord injury (SCI), paraplegia (PARA), and tetraplegia (TETRA). METHODS Twenty-four healthy males (eight able-bodied [AB], eight PARA, and eight TETRA) consumed 3 mg·kg caffeine anhydrous (CAF) in a fasted state. Plasma caffeine [CAF], glucose, lactate, free fatty acid, and catecholamine concentrations were measured during a 150-min rest period. RESULTS Peak [CAF] was greater in TETRA (21.5 μM) compared with AB (12.2 μM) and PARA (15.1 μM), and mean peak [CAF] occurred at 70, 80, and 80 min, respectively. Moderate and large effect sizes were revealed for TETRA compared with PARA and AB (-0.55 and -1.14, respectively) for the total area under the [CAF] versus time curve. Large interindividual responses were apparent in SCI groups. The change in plasma catecholamine concentrations after CAF did not reach significance (P > 0.05); however, both adrenaline and noradrenaline concentrations were lowest in TETRA. Significant increases in free fatty acid were seen over time (P < 0.0005), but there was no significant influence of SCI level. Blood lactate concentration reduced over time (P = 0.022), whereas blood glucose concentration decreased modestly (P = 0.695), and no difference between groups was seen (P > 0.05). CONCLUSION The level of SCI influenced the caffeine absorption curve, and there was large interindividual variation within and between groups. Individual curves should be considered when using caffeine as an ergogenic aid in athletes with an SCI. The results indicate TETRA should trial low doses in training and PARA may consider consuming caffeine greater than 60 min before exercise performance. The study also supports caffeine's direct effect on adipose tissue, which is not secondary to catecholamine release.
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Affiliation(s)
- Terri Susan Graham-Paulson
- 1Peter Harrison Centre for Disability Sport, School of Sport, Exercise and Health Sciences, Loughborough University, Leicestershire, UNITED KINGDOM; 2Swiss Paraplegic Centre, Institute of Sport Medicine, Nottwil, SWITZERLAND; and 3School of Sport, Exercise and Health Sciences, Loughborough University, Leicestershire, UNITED KINGDOM
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Collins PB, Earnest CP, Dalton RL, Sowinski RJ, Grubic TJ, Favot CJ, Coletta AM, Rasmussen C, Greenwood M, Kreider RB. Short-Term Effects of a Ready-to-Drink Pre-Workout Beverage on Exercise Performance and Recovery. Nutrients 2017; 9:nu9080823. [PMID: 28763003 PMCID: PMC5579616 DOI: 10.3390/nu9080823] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 07/25/2017] [Accepted: 07/27/2017] [Indexed: 01/07/2023] Open
Abstract
In a double-blind, randomized and crossover manner, 25 resistance-trained participants ingested a placebo (PLA) beverage containing 12 g of dextrose and a beverage (RTD) containing caffeine (200 mg), β-alanine (2.1 g), arginine nitrate (1.3 g), niacin (65 mg), folic acid (325 mcg), and Vitamin B12 (45 mcg) for 7-days, separated by a 7-10-day. On day 1 and 6, participants donated a fasting blood sample and completed a side-effects questionnaire (SEQ), hemodynamic challenge test, 1-RM and muscular endurance tests (3 × 10 repetitions at 70% of 1-RM with the last set to failure on the bench press (BP) and leg press (LP)) followed by ingesting the assigned beverage. After 15 min, participants repeated the hemodynamic test, 1-RM tests, and performed a repetition to fatigue (RtF) test at 70% of 1-RM, followed by completing the SEQ. On day 2 and 7, participants donated a fasting blood sample, completed the SEQ, ingested the assigned beverage, rested 30 min, and performed a 4 km cycling time-trial (TT). Data were analyzed by univariate, multivariate, and repeated measures general linear models (GLM), adjusted for gender and relative caffeine intake. Data are presented as mean change (95% CI). An overall multivariate time × treatment interaction was observed on strength performance variables (p = 0.01). Acute RTD ingestion better maintained LP 1-RM (PLA: -0.285 (-0.49, -0.08); RTD: 0.23 (-0.50, 0.18) kg/kgFFM, p = 0.30); increased LP RtF (PLA: -2.60 (-6.8, 1.6); RTD: 4.00 (-0.2, 8.2) repetitions, p = 0.031); increased BP lifting volume (PLA: 0.001 (-0.13, 0.16); RTD: 0.03 (0.02, 0.04) kg/kgFFM, p = 0.007); and, increased total lifting volume (PLA: -13.12 (-36.9, 10.5); RTD: 21.06 (-2.7, 44.8) kg/kgFFM, p = 0.046). Short-term RTD ingestion maintained baseline LP 1-RM (PLA: -0.412 (-0.08, -0.07); RTD: 0.16 (-0.50, 0.18) kg/kgFFM, p = 0.30); LP RtF (PLA: 0.12 (-3.0, 3.2); RTD: 3.6 (0.5, 6.7) repetitions, p = 0.116); and, LP lifting volume (PLA: 3.64 (-8.8, 16.1); RTD: 16.25 (3.8, 28.7) kg/kgFFM, p = 0.157) to a greater degree than PLA. No significant differences were observed between treatments in cycling TT performance, hemodynamic assessment, fasting blood panels, or self-reported side effects.
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Affiliation(s)
- Patrick B Collins
- Exercise and Sport Nutrition Lab, Human Clinical Research Facility, Texas A&M University, College Station, TX 77843, USA.
| | - Conrad P Earnest
- Exercise and Sport Nutrition Lab, Human Clinical Research Facility, Texas A&M University, College Station, TX 77843, USA.
- Nutrabolt, Bryan, 3891 S. Traditions Drive, Bryan, TX 77807, USA.
| | - Ryan L Dalton
- Exercise and Sport Nutrition Lab, Human Clinical Research Facility, Texas A&M University, College Station, TX 77843, USA.
| | - Ryan J Sowinski
- Exercise and Sport Nutrition Lab, Human Clinical Research Facility, Texas A&M University, College Station, TX 77843, USA.
| | - Tyler J Grubic
- Exercise and Sport Nutrition Lab, Human Clinical Research Facility, Texas A&M University, College Station, TX 77843, USA.
| | - Christopher J Favot
- Exercise and Sport Nutrition Lab, Human Clinical Research Facility, Texas A&M University, College Station, TX 77843, USA.
| | - Adriana M Coletta
- Exercise and Sport Nutrition Lab, Human Clinical Research Facility, Texas A&M University, College Station, TX 77843, USA.
| | - Christopher Rasmussen
- Exercise and Sport Nutrition Lab, Human Clinical Research Facility, Texas A&M University, College Station, TX 77843, USA.
| | - Mike Greenwood
- Exercise and Sport Nutrition Lab, Human Clinical Research Facility, Texas A&M University, College Station, TX 77843, USA.
| | - Richard B Kreider
- Exercise and Sport Nutrition Lab, Human Clinical Research Facility, Texas A&M University, College Station, TX 77843, USA.
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Matvienko TY, Zavodovskyi DA, Nozdrenko DN, Mishchenko IV, Motuziuk OP, Bogutska KI, Sklyarov YP, Prylutskyy YI. [MUSCLE FATIGUE: FACTORS OF DEVELOPMENT AND WAYS OF CORRECTION]. FIZIOLOHICHNYI ZHURNAL (KIEV, UKRAINE : 1994) 2017; 63:95-104. [PMID: 29975834 DOI: 10.15407/fz63.01.095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The data regarding the analysis of the physiological and biochemical mechanisms of muscle fatigue and ways to prevent it are summarized. The effect of the most common endogenous and exogenous antioxidants in the biochemical processes in muscle fatigue was analyzed. It is shown that biocompatible, non-toxic water-soluble C(60) fullerenes, which possess powerful antioxidative properties, promise great prospects in the correction of skeletal muscle fatigue caused by the destructive action of free radicals.
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Claghorn GC, Thompson Z, Wi K, Van L, Garland T. Caffeine stimulates voluntary wheel running in mice without increasing aerobic capacity. Physiol Behav 2016; 170:133-140. [PMID: 28039074 DOI: 10.1016/j.physbeh.2016.12.031] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 12/23/2016] [Accepted: 12/23/2016] [Indexed: 12/23/2022]
Abstract
The "energy drink" Red Bull and the "sports drink" Gatorade are often marketed to athletes, with claims that they cause performance gains. However, both are high in sugars, and also consumed by non-athletes. Few studies have addressed the effects of these drinks or their biologically active components in rodent exercise models. We used three experiments to test effects on both voluntary exercise behavior and maximal aerobic capacity in lines of mice known to differ in "athletic" traits. Mice from four replicate High Runner (HR) lines have been selectively bred for voluntary running on wheels, and run approximately three times as many revolutions per day as do mice from four non-selected Control (C) lines. HR mice also have higher endurance and maximal oxygen consumption (VO2max) during forced treadmill exercise. In Experiment 1, we tested the hypothesis that Gatorade or Red Bull might cause or allow mice to increase their voluntary wheel running. On days 5 and 6 of 6days of wheel access, as is used to select breeders, HR mice ran 3.3-fold more than C, and females ran 1.2-fold more than males, with no linetype by sex interaction. On day 7, mice were administered Gatorade, Red Bull or tap water. During the subsequent 19-hour period, Gatorade had no statistical effect on running, but Red Bull significantly increased distance run by both sexes and in both HR and C lines. The increase in distance run caused by Red Bull was attributable to time spent running, not an increase in mean (or maximum) speed. As previous studies have found that sucrose alone does not generally increase wheel running, we tested two other active ingredients in Red Bull, caffeine and taurine, in Experiment 2. With a similar testing protocol, caffeine alone and caffeine+taurine increased running by about half the magnitude of Red Bull. In Experiment 3, we tested the hypothesis that Red Bull or caffeine alone can increase physiological performance ability during aerobic exercise, measured as VO2max. In a repeated-measures design spanning 6days, females were housed with water bottles containing Red Bull, caffeine or water in a randomized order, and tested for VO2max twice while receiving each fluid (6 total trials). Neither Red Bull nor caffeine significantly affected either VO2max or a measure of trial cooperativity (rated on a scale of 1-5), but both treatments significantly reduced tiredness (rated on a scale of 1-3) scored at the end of trials for both HR and C lines. Taken together, our results suggest that caffeine increases voluntary exercise levels of mice by delaying fatigue, rather than increasing aerobic capacity.
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Affiliation(s)
- Gerald C Claghorn
- Department of Biology, University of California, Riverside, CA 92521, USA
| | - Zoe Thompson
- Department of Biology, University of California, Riverside, CA 92521, USA
| | - Kristianna Wi
- Department of Biology, University of California, Riverside, CA 92521, USA
| | - Lindsay Van
- Department of Biology, University of California, Riverside, CA 92521, USA
| | - Theodore Garland
- Department of Biology, University of California, Riverside, CA 92521, USA.
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McLellan TM, Caldwell JA, Lieberman HR. A review of caffeine’s effects on cognitive, physical and occupational performance. Neurosci Biobehav Rev 2016; 71:294-312. [DOI: 10.1016/j.neubiorev.2016.09.001] [Citation(s) in RCA: 253] [Impact Index Per Article: 31.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 08/26/2016] [Accepted: 09/04/2016] [Indexed: 12/31/2022]
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Glaister M, Williams BH, Muniz-Pumares D, Balsalobre-Fernández C, Foley P. The Effects of Caffeine Supplementation on Physiological Responses to Submaximal Exercise in Endurance-Trained Men. PLoS One 2016; 11:e0161375. [PMID: 27532605 PMCID: PMC4988702 DOI: 10.1371/journal.pone.0161375] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 08/04/2016] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVES The aim of this study was to evaluate the effects of caffeine on physiological responses to submaximal exercise, with a focus on blood lactate concentration ([BLa]). METHODS Using a randomised, single-blind, crossover design; 16 endurance-trained, male cyclists (age: 38 ± 8 years; height: 1.80 ± 0.05 m; body mass: 76.6 ± 7.8 kg; [Formula: see text]: 4.3 ± 0.6 L∙min-1) completed four trials on an electromagnetically-braked cycle ergometer. Each trial consisted of a six-stage incremental test (3 minute stages) followed by 30 minutes of passive recovery. One hour before trials 2-4, participants ingested a capsule containing 5 mg∙kg-1 of either caffeine or placebo (maltodextrin). Trials 2 and 3 were designed to evaluate the effects of caffeine on various physiological responses during exercise and recovery. In contrast, Trial 4 was designed to evaluate the effects of caffeine on [BLa] during passive recovery from an end-exercise concentration of 4 mmol∙L-1. RESULTS Relative to placebo, caffeine increased [BLa] during exercise, independent of exercise intensity (mean difference: 0.33 ± 0.41 mmol∙L-1; 95% likely range: 0.11 to 0.55 mmol∙L-1), but did not affect the time-course of [BLa] during recovery (p = 0.604). Caffeine reduced ratings of perceived exertion (mean difference: 0.5 ± 0.7; 95% likely range: 0.1 to 0.9) and heart rate (mean difference: 3.6 ± 4.2 b∙min-1; 95% likely range: 1.3 to 5.8 b∙min-1) during exercise, with the effect on the latter dissipating as exercise intensity increased. Supplement × exercise intensity interactions were observed for respiratory exchange ratio (p = 0.004) and minute ventilation (p = 0.034). CONCLUSIONS The results of the present study illustrate the clear, though often subtle, effects of caffeine on physiological responses to submaximal exercise. Researchers should be aware of these responses, particularly when evaluating the physiological effects of various experimental interventions.
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Affiliation(s)
- Mark Glaister
- School of Sport, Health, and Applied Sciences, St Mary’s University, Strawberry Hill, Twickenham, United Kingdom
- * E-mail:
| | - Benjamin Henley Williams
- School of Sport, Health, and Applied Sciences, St Mary’s University, Strawberry Hill, Twickenham, United Kingdom
| | - Daniel Muniz-Pumares
- School of Sport, Health, and Applied Sciences, St Mary’s University, Strawberry Hill, Twickenham, United Kingdom
| | | | - Paul Foley
- Cardiff School of Health Sciences, Cardiff Metropolitan University, Cardiff, United Kingdom
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Ratamess NA, Bush JA, Kang J, Kraemer WJ, Stohs SJ, Nocera VG, Leise MD, Diamond KB, Campbell SC, Miller HB, Faigenbaum AD. The Effects of Supplementation withp-Synephrine Alone and in Combination with Caffeine on Metabolic, Lipolytic, and Cardiovascular Responses during Resistance Exercise. J Am Coll Nutr 2016; 35:657-669. [DOI: 10.1080/07315724.2016.1150223] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Ribeiro BG, Morales AP, Sampaio-Jorge F, Barth T, de Oliveira MBC, Coelho GMDO, Leite TC. Caffeine Attenuates Decreases in Leg Power Without Increased Muscle Damage. J Strength Cond Res 2016; 30:2354-60. [PMID: 26808856 DOI: 10.1519/jsc.0000000000001332] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Beatriz G Ribeiro
- 1Laboratory Research and Innovation in Sports Sciences, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil; 2Macaé Sports Foundation, City Government of Macaé (PMM), Rio de Janeiro, Brazil; 3Laboratory of Chemistry and Biomolecules, Higher Institutes of Education of CENSA (ISECENSA), Rio de Janeiro, Brazil; 4Laboratory of Natural Products, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil; and 5Rio de Janeiro State University, Rio de Janeiro, Brazil
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Sugita M, Kapoor MP, Nishimura A, Okubo T. Influence of green tea catechins on oxidative stress metabolites at rest and during exercise in healthy humans. Nutrition 2016; 32:321-31. [DOI: 10.1016/j.nut.2015.09.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Revised: 06/22/2015] [Accepted: 09/11/2015] [Indexed: 01/18/2023]
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Glaister M, Pattison JR, Muniz-Pumares D, Patterson SD, Foley P. Effects of dietary nitrate, caffeine, and their combination on 20-km cycling time trial performance. J Strength Cond Res 2015; 29:165-74. [PMID: 24978834 DOI: 10.1519/jsc.0000000000000596] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The aim of this study was to examine the acute supplementation effects of dietary nitrate, caffeine, and their combination on 20-km cycling time trial performance. Using a randomized, counterbalanced, double-blind Latin-square design, 14 competitive female cyclists (age: 31 ± 7 years; height: 1.69 ± 0.07 m; body mass: 61.6 ± 6.0 kg) completed four 20-km time trials on a racing bicycle fitted to a turbo trainer. Approximately 2.5 hours before each trial, subjects consumed a 70-ml dose of concentrated beetroot juice containing either 0.45 g of dietary nitrate or with the nitrate content removed (placebo). One hour before each trial, subjects consumed a capsule containing either 5 mg·kg of caffeine or maltodextrin (placebo). There was a significant effect of supplementation on power output (p = 0.001), with post hoc tests revealing higher power outputs in caffeine (205 ± 21 W) vs. nitrate (194 ± 22 W) and placebo (194 ± 25 W) trials only. Caffeine-induced improvements in power output corresponded with significantly higher measures of heart rate (caffeine: 166 ± 12 b·min vs. placebo: 159 ± 15 b·min; p = 0.02), blood lactate (caffeine: 6.54 ± 2.40 mmol·L vs. placebo: 4.50 ± 2.11 mmol·L; p < 0.001), and respiratory exchange ratio (caffeine: 0.95 ± 0.04 vs. placebo: 0.91 ± 0.05; p = 0.03). There were no effects (p ≥ 0.05) of supplementation on cycling cadence, rating of perceived exertion, (Equation is included in full-text article.), or integrated electromyographic activity. The results of this study support the well-established beneficial effects of caffeine supplementation on endurance performance. In contrast, acute supplementation with dietary nitrate seems to have no effect on endurance performance and adds nothing to the benefits afforded by caffeine supplementation.
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Affiliation(s)
- Mark Glaister
- 1School of Sport, Health, and Applied Sciences, St Mary's University College, Strawberry Hill, Twickenham, United Kingdom; and 2Cardiff School of Health Sciences, Cardiff Metropolitan University, Cardiff, United Kingdom
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Craig DM, Ashcroft SP, Belew MY, Stocks B, Currell K, Baar K, Philp A. Utilizing small nutrient compounds as enhancers of exercise-induced mitochondrial biogenesis. Front Physiol 2015; 6:296. [PMID: 26578969 PMCID: PMC4621424 DOI: 10.3389/fphys.2015.00296] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 10/06/2015] [Indexed: 01/09/2023] Open
Abstract
Endurance exercise, when performed regularly as part of a training program, leads to increases in whole-body and skeletal muscle-specific oxidative capacity. At the cellular level, this adaptive response is manifested by an increased number of oxidative fibers (Type I and IIA myosin heavy chain), an increase in capillarity and an increase in mitochondrial biogenesis. The increase in mitochondrial biogenesis (increased volume and functional capacity) is fundamentally important as it leads to greater rates of oxidative phosphorylation and an improved capacity to utilize fatty acids during sub-maximal exercise. Given the importance of mitochondrial biogenesis for skeletal muscle performance, considerable attention has been given to understanding the molecular cues stimulated by endurance exercise that culminate in this adaptive response. In turn, this research has led to the identification of pharmaceutical compounds and small nutritional bioactive ingredients that appear able to amplify exercise-responsive signaling pathways in skeletal muscle. The aim of this review is to discuss these purported exercise mimetics and bioactive ingredients in the context of mitochondrial biogenesis in skeletal muscle. We will examine proposed modes of action, discuss evidence of application in skeletal muscle in vivo and finally comment on the feasibility of such approaches to support endurance-training applications in humans.
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Affiliation(s)
- Daniel M Craig
- MRC Arthritis Research UK Centre for Musculoskeletal Ageing Research, School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham Birmingham, UK
| | - Stephen P Ashcroft
- MRC Arthritis Research UK Centre for Musculoskeletal Ageing Research, School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham Birmingham, UK
| | - Micah Y Belew
- Molecular, Cell and Cancer Biology, University of Massachusetts Medical School Worcester, MA, USA
| | - Ben Stocks
- MRC Arthritis Research UK Centre for Musculoskeletal Ageing Research, School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham Birmingham, UK
| | - Kevin Currell
- EIS Performance Centre, English Institute of Sport, Loughborough University Loughborough, UK
| | - Keith Baar
- Neurobiology, Physiology and Behavior, University of California Davis Davis, CA, USA
| | - Andrew Philp
- MRC Arthritis Research UK Centre for Musculoskeletal Ageing Research, School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham Birmingham, UK
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Church DD, Hoffman JR, LaMonica MB, Riffe JJ, Hoffman MW, Baker KM, Varanoske AN, Wells AJ, Fukuda DH, Stout JR. The effect of an acute ingestion of Turkish coffee on reaction time and time trial performance. J Int Soc Sports Nutr 2015; 12:37. [PMID: 26445565 PMCID: PMC4595106 DOI: 10.1186/s12970-015-0098-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 09/29/2015] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND The purpose of this study was to examine the ergogenic benefits of Turkish coffee consumed an hour before exercise. In addition, metabolic, cardiovascular, and subjective measures of energy, focus and alertness were examined in healthy, recreationally active adults who were regular caffeine consumers (>200 mg per day). METHODS Twenty males (n = 10) and females (n = 10), age 24.1 ± 2.9 y; height 1.70 ± 0.09 m; body mass 73.0 ± 13.0 kg (mean ± SD), ingested both Turkish coffee [3 mg · kg(-1) BW of caffeine, (TC)], and decaffeinated Turkish coffee (DC) in a double-blind, randomized, cross-over design. Performance measures included a 5 km time trial, upper and lower body reaction to visual stimuli, and multiple object tracking. Plasma caffeine concentrations, blood pressure (BP), heart rate and subjective measures of energy, focus and alertness were assessed at baseline (BL), 30-min following coffee ingestion (30+), prior to endurance exercise (PRE) and immediately-post 5 km (IP). Metabolic measures [VO2, V E , and respiratory exchange rate (RER)] were measured during the 5 km. RESULTS Plasma caffeine concentrations were significantly greater during TC (p < 0.001) at 30+, PRE, and IP compared to DC. Significantly higher energy levels were reported at 30+ and PRE for TC compared to DC. Upper body reaction performance (p = 0.023) and RER (p = 0.019) were significantly higher for TC (85.1 ± 11.6 "hits," and 0.98 ± 0.05 respectively) compared to DC (81.2 ± 13.7 "hits," and 0.96 ± 0.05, respectively). Although no significant differences (p = 0.192) were observed in 5 km run time, 12 of the 20 subjects ran faster (p = 0.012) during TC (1662 ± 252 s) compared to DC (1743 ± 296 s). Systolic BP was significantly elevated during TC in comparison to DC. No other differences (p > 0.05) were noted in any of the other performance or metabolic measures. CONCLUSIONS Acute ingestion of TC resulted in a significant elevation in plasma caffeine concentrations within 30-min of consumption. TC ingestion resulted in significant performance benefits in reaction time and an increase in subjective feelings of energy in habitual caffeine users. No significant differences were noted in time for the 5 km between trials, however 60 % of the participants performed the 5 km faster during the TC trial and were deemed responders. When comparing TC to DC in responders only, significantly faster times were noted when consuming TC compared to DC. No significant benefits were noted in measures of cognitive function.
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Affiliation(s)
- David D. Church
- Institute of Exercise Physiology and Wellness, Sport and Exercise Science, University of Central Florida, 12494 University Blvd, Orlando, FL 32816-1250 USA
| | - Jay R. Hoffman
- Institute of Exercise Physiology and Wellness, Sport and Exercise Science, University of Central Florida, 12494 University Blvd, Orlando, FL 32816-1250 USA
| | - Michael B. LaMonica
- Institute of Exercise Physiology and Wellness, Sport and Exercise Science, University of Central Florida, 12494 University Blvd, Orlando, FL 32816-1250 USA
| | - Joshua J. Riffe
- Institute of Exercise Physiology and Wellness, Sport and Exercise Science, University of Central Florida, 12494 University Blvd, Orlando, FL 32816-1250 USA
| | - Mattan W. Hoffman
- Institute of Exercise Physiology and Wellness, Sport and Exercise Science, University of Central Florida, 12494 University Blvd, Orlando, FL 32816-1250 USA
| | - Kayla M. Baker
- Institute of Exercise Physiology and Wellness, Sport and Exercise Science, University of Central Florida, 12494 University Blvd, Orlando, FL 32816-1250 USA
| | - Alyssa N. Varanoske
- Institute of Exercise Physiology and Wellness, Sport and Exercise Science, University of Central Florida, 12494 University Blvd, Orlando, FL 32816-1250 USA
| | - Adam J. Wells
- Institute of Exercise Physiology and Wellness, Sport and Exercise Science, University of Central Florida, 12494 University Blvd, Orlando, FL 32816-1250 USA
| | - David H. Fukuda
- Institute of Exercise Physiology and Wellness, Sport and Exercise Science, University of Central Florida, 12494 University Blvd, Orlando, FL 32816-1250 USA
| | - Jeffrey R. Stout
- Institute of Exercise Physiology and Wellness, Sport and Exercise Science, University of Central Florida, 12494 University Blvd, Orlando, FL 32816-1250 USA
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Cruz RSDO, de Aguiar RA, Turnes T, Guglielmo LGA, Beneke R, Caputo F. Caffeine Affects Time to Exhaustion and Substrate Oxidation during Cycling at Maximal Lactate Steady State. Nutrients 2015; 7:5254-64. [PMID: 26133971 PMCID: PMC4516996 DOI: 10.3390/nu7075219] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Revised: 06/08/2015] [Accepted: 06/15/2015] [Indexed: 11/24/2022] Open
Abstract
This study analyzed the effects of caffeine intake on whole-body substrate metabolism and exercise tolerance during cycling by using a more individualized intensity for merging the subjects into homogeneous metabolic responses (the workload associated with the maximal lactate steady state—MLSS). MLSS was firstly determined in eight active males (25 ± 4 years, 176 ± 7 cm, 77 ± 11 kg) using from two to four constant-load tests of 30 min. On two following occasions, participants performed a test until exhaustion at the MLSS workload 1 h after taking either 6 mg/kg of body mass of caffeine or placebo (dextrose), in a randomized, double-blinded manner. Respiratory exchange ratio was calculated from gas exchange measurements. There was an improvement of 22.7% in time to exhaustion at MLSS workload following caffeine ingestion (95% confidence limits of ±10.3%, p = 0.002), which was accompanied by decrease in respiratory exchange ratio (p = 0.001). These results reinforce findings indicating that sparing of the endogenous carbohydrate stores could be one of the several physiological effects of caffeine during submaximal performance around 1 h.
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Affiliation(s)
- Rogério Santos de Oliveira Cruz
- Santa Catarina State University, Human Performance Research Group, Rua Pascoal Simone, 358, Coqueiros, Florianópolis, Santa Catarina 88080-350, Brazil.
| | - Rafael Alves de Aguiar
- Santa Catarina State University, Human Performance Research Group, Rua Pascoal Simone, 358, Coqueiros, Florianópolis, Santa Catarina 88080-350, Brazil.
| | - Tiago Turnes
- Santa Catarina State University, Human Performance Research Group, Rua Pascoal Simone, 358, Coqueiros, Florianópolis, Santa Catarina 88080-350, Brazil.
| | | | - Ralph Beneke
- Abt. Medizin, Training und Gesundheit, Inst. Sportwissenschaft und Motologie, Philipps Universität Marburg, Marburg 35037, Germany.
| | - Fabrizio Caputo
- Santa Catarina State University, Human Performance Research Group, Rua Pascoal Simone, 358, Coqueiros, Florianópolis, Santa Catarina 88080-350, Brazil.
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BLACK CHRISTOPHERD, WADDELL DWIGHTE, GONGLACH ALEXANDERR. Caffeine’s Ergogenic Effects on Cycling. Med Sci Sports Exerc 2015; 47:1145-58. [DOI: 10.1249/mss.0000000000000513] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Caffeine-induced increase in voluntary activation and strength of the quadriceps muscle during isometric, concentric and eccentric contractions. Sci Rep 2015; 5:10209. [PMID: 25969895 PMCID: PMC4429543 DOI: 10.1038/srep10209] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 04/02/2015] [Indexed: 11/17/2022] Open
Abstract
This study investigated effects of caffeine ingestion (8 mg/kg) on maximum voluntary torque (MVT) and voluntary activation of the quadriceps during isometric, concentric and eccentric contractions. Fourteen subjects ingested caffeine and placebo in a randomized, controlled, counterbalanced, double-blind crossover design. Neuromuscular tests were performed before and 1 h after oral caffeine and placebo intake. MVTs were measured and the interpolated twitch technique was applied during isometric, concentric and eccentric contractions to assess voluntary activation. Furthermore, normalized root mean square of the EMG signal was calculated and evoked spinal reflex responses (H-reflex evoked at rest and during weak isometric voluntary contraction) as well as twitch torques were analyzed. Caffeine increased MVT by 26.4 N m (95%CI: 9.3-43.5 N m, P = 0.004), 22.5 N m (95%CI: 3.1-42.0 N m, P = 0.025) and 22.5 N m (95%CI: 2.2-42.7 N m, P = 0.032) for isometric, concentric and eccentric contractions. Strength enhancements were associated with increases in voluntary activation. Explosive voluntary strength and voluntary activation at the onset of contraction were significantly increased following caffeine ingestion. Changes in spinal reflex responses and at the muscle level were not observed. Data suggest that caffeine ingestion induced an acute increase in voluntary activation that was responsible for the increased strength regardless of the contraction mode.
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Shearer J, Graham TE. Performance effects and metabolic consequences of caffeine and caffeinated energy drink consumption on glucose disposal. Nutr Rev 2015; 72 Suppl 1:121-36. [PMID: 25293551 DOI: 10.1111/nure.12124] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
This review documents two opposing effects of caffeine and caffeine-containing energy drinks, i.e., their positive effects on athletic performance and their negative impacts on glucose tolerance in the sedentary state. Analysis of studies examining caffeine administration prior to performance-based exercise showed caffeine improved completion time by 3.6%. Similar analyses following consumption of caffeine-containing energy drinks yielded positive, but more varied, benefits, which were likely due to the diverse nature of the studies performed, the highly variable composition of the beverages consumed, and the range of caffeine doses administered. Conversely, analyses of studies administering caffeine prior to either an oral glucose tolerance test or insulin clamp showed a decline in whole-body glucose disposal of ~30%. The consequences of this resistance are unknown, but there may be implications for the development of a number of chronic diseases. Both caffeine-induced performance enhancement and insulin resistance converge with the primary actions of caffeine on skeletal muscle.
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Affiliation(s)
- Jane Shearer
- Department of Biochemistry & Molecular Biology, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada
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Seifert JG, Connor DA. The influence of commercial energy shots on response time and power output in recreational cyclists. J Int Soc Sports Nutr 2014; 11:56. [PMID: 25512745 PMCID: PMC4266199 DOI: 10.1186/s12970-014-0056-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Accepted: 10/30/2014] [Indexed: 11/15/2022] Open
Abstract
Background Caffeine based energy shot products accounted for $1.3 billion in sales in 2011. Caffeine has been shown to confer numerous benefits during exercise and is oftentimes combined with ingredients such as carbohydrates and taurine in the hope of further performance improvement. The purpose of this project was to compare auditory response time, power output, and physiological responses between the ingestion of a CHO, PRO, caffeine supplement (CPC), a caffeine-taurine-niacin based supplement (CTN), and a placebo (PL) in commercially formulated products that make claims as to improving performance. Methods Fourteen subjects cycled an interval exercise of 70% VO2max for 13 minutes and 90% of VO2max for two minutes for a total of 120 minutes which was then followed by a six-minute power output (PO) task. Subjects ingested a total of 45 g CHO, 7.5 g PRO, and 375 mg caffeine for CPC while 512 mg caffeine and 1200 mg taurine were ingested for CTN throughout the exercise. The treatments were administered in a double blind, randomly assigned protocol. Response time was assessed by auditory response. Significance was set at p < 0.05. Results Average PO was significantly greater for CPC: 309 ± 60 W than CTN: 290 ± 57 W and PL: 282 ± 63 W. Response time was significantly faster for the CPC: 0.219 ± .049 s than CTN: 0.232 ± .060 s and PL: 0.228 ± .047 s. HR was significantly greater for CTN: 143 ± 16 bpm than CPC: 139 ± 16 bpm. RPE was significantly lower for CPC: 13.0 ± 1.7 than CTN: 13.5 ± 1.2 and PL: 13.8 ± 1.9. Blood glucose was greater for CPC: 5.5 ± 0.8 mM/L than CTN: 4.9 ± 0.7 mM/L and PL: 4.6 ± 1.1 mM/L. No significant differences were observed for RER. Conclusions The co-ingestion of CPC improved both cycling power output and auditory response time following 2 hours of moderate and high intensity interval cycling compared to CTN and PL. It is possible that the CPC treatment conferred not only a positive peripheral effect, but also a central effect. Even with a large caffeine dose, the combination of caffeine, taurine, niacin led to an inhibitory pattern which did not improve power output or response time performances over a PL.
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Affiliation(s)
- John G Seifert
- Movement Science Laboratory, Montana State University, Bozeman, MT 59717 USA
| | - David A Connor
- Movement Science Laboratory, Montana State University, Bozeman, MT 59717 USA
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Abstract
Accumulating evidence suggests that diet and lifestyle can play an important role in delaying the onset or halting the progression of age-related health disorders and can improve cognitive function. Exercise has been promoted as a possible prevention for neurodegenerative diseases. Exercise will have a positive influence on cognition and it increases the brain-derived neurotrophic factor, an essential neurotrophin. Several dietary components have been identified as having effects on cognitive abilities. In particular, polyphenols have been reported to exert their neuroprotective actions through the potential to protect neurons against injury induced by neurotoxins, an ability to suppress neuroinflammation, and the potential to promote memory, learning, and cognitive function. Dietary factors can affect multiple brain processes by regulating neurotransmitter pathways, synaptic transmission, membrane fluidity, and signal-transduction pathways. Flavonols are part of the flavonoid family that is found in various fruits, cocoa, wine, tea and beans. Although the antioxidant effects of flavonols are well established in vitro, there is general agreement that flavonols have more complex actions in vivo. Several cross-sectional and longitudinal studies have shown that a higher intake of flavonoids from food may be associated with a better cognitive evolution. Whether this reflects a causal association remains to be elucidated. Several studies have tried to 'manipulate' the brain in order to postpone central fatigue. Most studies have clearly shown that in normal environmental circumstances these interventions are not easy to perform. There is accumulating evidence that rinsing the mouth with a carbohydrate solution will improve endurance performance. There is a need for additional well controlled studies to explore the possible impact of diet and nutrition on brain functioning.
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Abstract
Caffeine is a popular work-enhancing supplement that has been actively researched since the 1970s. The majority of research has examined the effects of moderate to high caffeine doses (5-13 mg/kg body mass) on exercise and sport. These caffeine doses have profound effects on the responses to exercise at the whole-body level and are associated with variable results and some undesirable side effects. Low doses of caffeine (<3 mg/kg body mass, ~200 mg) are also ergogenic in some exercise and sport situations, although this has been less well studied. Lower caffeine doses (1) do not alter the peripheral whole-body responses to exercise; (2) improve vigilance, alertness, and mood and cognitive processes during and after exercise; and (3) are associated with few, if any, side effects. Therefore, the ergogenic effect of low caffeine doses appears to result from alterations in the central nervous system. However, several aspects of consuming low doses of caffeine remain unresolved and suffer from a paucity of research, including the potential effects on high-intensity sprint and burst activities. The responses to low doses of caffeine are also variable and athletes need to determine whether the ingestion of ~200 mg of caffeine before and/or during training and competitions is ergogenic on an individual basis.
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Affiliation(s)
- Lawrence L Spriet
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, N1G 2W1, Canada,
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