1
|
Antonio J, Newmire DE, Stout JR, Antonio B, Gibbons M, Lowery LM, Harper J, Willoughby D, Evans C, Anderson D, Goldstein E, Rojas J, Monsalves-Álvarez M, Forbes SC, Gomez Lopez J, Ziegenfuss T, Moulding BD, Candow D, Sagner M, Arent SM. Common questions and misconceptions about caffeine supplementation: what does the scientific evidence really show? J Int Soc Sports Nutr 2024; 21:2323919. [PMID: 38466174 DOI: 10.1080/15502783.2024.2323919] [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: 12/04/2023] [Accepted: 02/17/2024] [Indexed: 03/12/2024] Open
Abstract
Caffeine is a popular ergogenic aid that has a plethora of evidence highlighting its positive effects. A Google Scholar search using the keywords "caffeine" and "exercise" yields over 200,000 results, emphasizing the extensive research on this topic. However, despite the vast amount of available data, it is intriguing that uncertainties persist regarding the effectiveness and safety of caffeine. These include but are not limited to: 1. Does caffeine dehydrate you at rest? 2. Does caffeine dehydrate you during exercise? 3. Does caffeine promote the loss of body fat? 4. Does habitual caffeine consumption influence the performance response to acute caffeine supplementation? 5. Does caffeine affect upper vs. lower body performance/strength differently? 6. Is there a relationship between caffeine and depression? 7. Can too much caffeine kill you? 8. Are there sex differences regarding caffeine's effects? 9. Does caffeine work for everyone? 10. Does caffeine cause heart problems? 11. Does caffeine promote the loss of bone mineral? 12. Should pregnant women avoid caffeine? 13. Is caffeine addictive? 14. Does waiting 1.5-2.0 hours after waking to consume caffeine help you avoid the afternoon "crash?" To answer these questions, we performed an evidence-based scientific evaluation of the literature regarding caffeine supplementation.
Collapse
Affiliation(s)
- Jose Antonio
- Nova Southeastern University, Department of Health and Human Performance, Davie, FL, USA
| | - Daniel E Newmire
- Texas Woman's University, Exercise Physiology and Biochemistry Laboratory, School of Health Promotion and Kinesiology, Denton, TX, USA
| | - Jeffrey R Stout
- University of Central Florida, College of Health Professions and Sciences, Orlando, FL, USA
| | - Brandi Antonio
- University of Central Florida, College of Health Professions and Sciences, Orlando, FL, USA
| | | | - Lonnie M Lowery
- Nutrition, Exercise and Wellness Associates, Cuyahoga Falls, OH, USA
- Walsh University, Department of Exercise Science, North Canton, OH, USA
| | - Joseph Harper
- Walsh University, Department of Exercise Science, North Canton, OH, USA
| | - Darryn Willoughby
- School of Exercise and Sport Science, University of Mary Hardin-Baylor, Belton, TX, USA
| | - Cassandra Evans
- Nova Southeastern University, Department of Health and Human Performance, Davie, FL, USA
| | - Dawn Anderson
- Indiana Tech, Exercise and Sport Performance Laboratory, Fort Wayne, IN, USA
| | - Erica Goldstein
- Stetson University, Department of Health Sciences, Deland, FL, USA
| | - Jose Rojas
- Keiser University, Fort Lauderdale, FL, USA
- Rocky Mountain University of Health Professions, Provo, UT, USA
| | - Matías Monsalves-Álvarez
- Universidad de O´Higgins, Exercise Metabolism and Nutrition Laboratory. Instituto de Ciencias de la Salud, Rancagua, Chile
- Motion Human Performance Laboratory, Lo Barnechea, Chile
| | - Scott C Forbes
- Brandon University, Department of Physical Education Studies, CBrandon, MB, Canada
| | | | - Tim Ziegenfuss
- The Center for Applied Health Sciences, Canfield, OH, USA
| | - Blake D Moulding
- University of Regina, Faculty of Kinesiology and Health Studies, Regina, SK, Canada
| | - Darren Candow
- University of Regina, Faculty of Kinesiology and Health Studies, Regina, SK, Canada
| | | | - Shawn M Arent
- University of South Carolina, Arnold School of Public Health, Columbia, SC, USA
| |
Collapse
|
2
|
Varillas-Delgado D, Coso JD, Muñoz A, Aguilar-Navarro M, Gutierrez-Hellin J. Influence of the CYP1A2 c. -163 A > C polymorphism in the effect of caffeine on fat oxidation during exercise: a pilot randomized, double-blind, crossover, placebo-controlled trial. Eur J Nutr 2024:10.1007/s00394-024-03454-3. [PMID: 39007997 DOI: 10.1007/s00394-024-03454-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Accepted: 06/20/2024] [Indexed: 07/16/2024]
Abstract
PURPOSE The aim of this study was to determine the influence of the CYP1A2 c.-163 A > C (rs762551) polymorphism on the effect of oral caffeine intake on fat oxidation during exercise. METHODS Using a pilot randomized, double-blind, crossover, placebo-controlled trial, 32 young and healthy individuals (women = 14, men = 18) performed an incremental test on a cycle ergometer with 3-min stages at workloads from 30 to 70% of maximal oxygen uptake (VO2max). Participants performed this test after the ingestion of (a) placebo; (b) 3 mg/kg of caffeine; (c) 6 mg/kg of caffeine. Fat oxidation rate during exercise was measured by indirect calorimetry. The influence of the CYP1A2 c.-163 A > C polymorphism in the effect of caffeine on fat oxidation rates during exercise was established with a three-way ANOVA (substance × genotype × intensity). RESULTS Eight participants were genotyped as AA, 18 participants were CA heterozygotes, and 6 participants were CC. There was a main effect of substance (F = 3.348, p = 0.050) on fat oxidation rates during exercise with no genotype effect (F = 0.158, p = 0.959). The post hoc analysis revealed that, in comparison to the placebo, 3 and 6 mg/kg of caffeine increased fat oxidation at 40-50% VO2max in AA (all p < 0.050) and 50-60% VO2max in CA and CC participants (all p < 0.050). CONCLUSION Oral intake of 3 and 6 mg/kg of caffeine increased fat oxidation rate during aerobic exercise in individuals with AA, CA and CC genotypes. This suggests that the effect of caffeine to enhance fat oxidation during exercise is not influenced by the CYP1A2 c.-163 A > C polymorphism. TRIAL REGISTRATION The study was registered on clinicaltrials.gov with ID: NCT05975489.
Collapse
Affiliation(s)
| | - Juan Del Coso
- Sport Sciences Research Centre, Rey Juan Carlos University, Madrid, Spain
| | - Alejandro Muñoz
- Faculty of Health Sciences, Universidad Francisco de Vitoria, Madrid, Spain.
| | | | | |
Collapse
|
3
|
Estrázulas JA, Pereira Dos Santos F, Taborda Machado AJ, Legnani E, Bertuzzi R, Lima-Silva AE. Effects of Acute Ingestion of Guarana ( Paullinia Cupana) on Soccer Player Performance: A Randomized, Cross-over, Placebo-Controlled Study. JOURNAL OF THE AMERICAN NUTRITION ASSOCIATION 2024:1-7. [PMID: 38958672 DOI: 10.1080/27697061.2024.2373189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 06/24/2024] [Indexed: 07/04/2024]
Abstract
OBJECTIVE To investigate the acute effects of ingesting a beverage containing guarana (Paullinia cupana) seed powder on performance during field tests related to physical capacities that are determinants of soccer performance, such as lower limb power, sprint, agility, and the capacity to carry out intermittent exercise. METHODS The study was conducted using a randomized, crossover, and counterbalanced design, with a beverage containing guarana or placebo administered in a double-blind manner. Twenty-seven under-17 soccer players of a professional soccer club performed a battery of tests 60 min after the ingestion of guarana (3 g of the fruit seed powder) or placebo. Trials were performed with a 7-day washout period. The battery of tests included a countermovement jump test, sprints of 10 and 20 m, an Illinois agility test, and a Yo-Yo Intermittent Recovery Test level 1 (YYIR1). RESULTS Guarana ingestion did not improve countermovement jump, sprints, or agility (p > 0.05). However, guarana ingestion increased the distance covered in the YYIR1, compared with placebo ingestion (p = 0.01). CONCLUSION Acute ingestion of guarana improves the capacity to perform intermittent exercise in soccer players but seems to be ineffective to improve lower limb power, sprint, and agility.
Collapse
Affiliation(s)
- Jaisson Agne Estrázulas
- Graduate Program in Physical Education, Federal University of Paraná, Curitiba, PR, Brazil
- Human Performance Research Group, Federal University of Technology-Paraná (UTFPR), Curitiba, PR, Brazil
| | | | - Ana Julia Taborda Machado
- Graduate Program in Health Sciences, School of Life Sciences and Medicine, Pontifical Catholic University of Paraná, Curitiba, PR, Brazil
| | - Elto Legnani
- Graduate Program in Physical Education, Federal University of Paraná, Curitiba, PR, Brazil
- Department of Physical Education, Federal University of Technology, Curitiba, PR, Brazil
| | - Romulo Bertuzzi
- Endurance Performance Research Group (GEDAE-USP), University of São Paulo, São Paulo, Brazil
| | | |
Collapse
|
4
|
Marocolo M, Mota GR, Rodrigues AB, Leite RCDM, Hohl R, Paixão RCD, Souza HLR, Meireles A, Arriel R. Unveiling Bias: Examining the Influence of Positive Results on Ergogenic Aids in Published Sports Science Studies. Sports Med Int Open 2024; 8:a21816798. [PMID: 38312926 PMCID: PMC10832574 DOI: 10.1055/a-2181-6798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 09/15/2023] [Indexed: 02/06/2024] Open
Abstract
We investigated the potential for publication bias in the field of sports science regarding studies on ergogenic aids and their effects on exercise performance. We found evidence to suggest that journals tend to prioritize studies with positive results (76%) while neglecting those with negative outcomes (2.7%). Worryingly, this could lead to a discrepancy between reported conclusions and actual study outcomes. We also identified inconsistencies between reported outcomes and actual performance variable outcomes. Taken together, these data highlight the need for future research to reduce bias and encourage the publication of studies with both positive and negative results to improve the reliability of scientific evidence in this field.
Collapse
Affiliation(s)
- Moacir Marocolo
- Department of Physiology, Institute of Biological Sciences, Federal
University of Juiz de Fora, Juiz de Fora, Brazil
| | - Gustavo R. Mota
- Department of Sports Science, Institute of Health Sciences, Federal
University of Triângulo Mineiro, Uberaba, Brazil
| | - Alex Batista Rodrigues
- Department of Physical Education and Sports, Federal University of Juiz
de Fora, Juiz de Fora, Brazil
| | - Roberto C. de Matos Leite
- Department of Physical Education and Sports, Federal University of Juiz
de Fora, Juiz de Fora, Brazil
| | - Rodrigo Hohl
- Department of Physiology, Institute of Biological Sciences, Federal
University of Juiz de Fora, Juiz de Fora, Brazil
| | - Rodney Coelho da Paixão
- Department of Physiology, Institute of Biological Sciences, Federal
University of Juiz de Fora, Juiz de Fora, Brazil
- Department of Physical Education and Physiotherapy, Federal University
of Uberlândia, Uberlândia, Brazil
| | - Hiago L. R. Souza
- Department of Physiology, Institute of Biological Sciences, Federal
University of Juiz de Fora, Juiz de Fora, Brazil
| | - Anderson Meireles
- Department of Physiology, Institute of Biological Sciences, Federal
University of Juiz de Fora, Juiz de Fora, Brazil
| | - Rhai Arriel
- Department of Physiology, Institute of Biological Sciences, Federal
University of Juiz de Fora, Juiz de Fora, Brazil
| |
Collapse
|
5
|
Cardiorespiratory, Metabolic, and Performance Changes from the Effects of Creatine and Caffeine Supplementations in Glucose-Electrolyte-Based Sports Drinks: A Double-Blind, Placebo-Controlled Study. Sports (Basel) 2022; 11:sports11010004. [PMID: 36668708 PMCID: PMC9862658 DOI: 10.3390/sports11010004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 12/20/2022] [Accepted: 12/20/2022] [Indexed: 12/25/2022] Open
Abstract
The purpose of this study is to investigate the additive effects of creatine and caffeine on changes in the cardiorespiratory system, metabolism, and performance of soccer players. Seventeen male soccer players randomly ingested three sports drinks comprising the following: glucose−electrolyte-based (Drink 1, control; D1), glucose−electrolyte-based drink + 5 g creatine (Drink 2; D2), and glucose−electrolyte-based drink + 5 g creatine + 35 mg caffeine (Drink 3; D3) during a 15 min recovery period after the modified Loughborough Intermittent Shuttle Test (LIST) on a standard outdoor soccer field. Then, a 20-m repeated intermittent sprinting activity was performed. The results showed no significant differences in cardiorespiratory and gas exchange variables. The non-significant levels of blood glucose concentrations among drinks with higher blood lactate concentrations were detected in parallel with increased heart rate during intermittent sprinting as a result of exercise intensities. Significantly longer sprinting time was found in D3 than D1 (p < 0.05), with no significant differences between D2 and D3. From this study, we conclude that the additive effect of caffeine−creatine supplements in a glucose−electrolyte drink during the 15 min recovery period enhances repeated 20-m high-intensity running in soccer players with no negative effect on cardiorespiratory functions.
Collapse
|
6
|
CYP1A2 Genotype Polymorphism Influences the Effect of Caffeine on Anaerobic Performance in Trained Males. Int J Sport Nutr Exerc Metab 2021; 32:16-21. [PMID: 34611052 DOI: 10.1123/ijsnem.2021-0090] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Revised: 08/17/2021] [Accepted: 08/18/2021] [Indexed: 11/18/2022]
Abstract
The purpose was to investigate the effects of CYP1A2 -163C > A polymorphism on the effects of acute caffeine (CAF) supplementation on anaerobic power in trained males. Sixteen trained males (age: 21.6 ± 7.1 years; height: 179.7 ± 5.6 cm; body mass: 72.15 ± 6.8 kg) participated in a randomized, double-blind, placebo (PLA) controlled crossover design. Participants supplemented with CAF (6 mg/kg of body mass) and an isovolumetric PLA (maltodextrin) in random order and separated by 7 days, before an all-out 30-s anaerobic cycling test to determine peak, average, and minimum power output, and fatigue index. Genomic deoxyribonucleic acid was extracted to identify each participants CYP1A2 genotype. Six participants expressed AA homozygote and 10 expressed C alleles. There was a treatment by genotype interaction for peak power output (p = .041, η2 = .265, observed power = 0.552) with only those expressing AA genotype showing improvement following CAF supplementation compared with PLA (CAF: 693 ± 108 watts vs. PLA: 655 ± 97 watts; p = .039), while no difference between treatments was noted in those expressing C alleles (CAF: 614 ± 92 watts vs. PLA: 659 ± 144 watts; p = .135). There were no other interaction or main effects for average or minimum power output, or fatigue index (p > .05). In conclusion, the ingestion of 6 mg/kg of CAF improved peak power output only in participants with the AA genotype compared with PLA; however, expression of the CYP1A2 did not influence average or minimum power output or fatigue index.
Collapse
|
7
|
Reactive diving and sprinting performances in soccer goalkeepers improved by caffeine consumption and post-activation performance enhancement. GERMAN JOURNAL OF EXERCISE AND SPORT RESEARCH 2021. [DOI: 10.1007/s12662-021-00746-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
8
|
Mendes GF, Reis CEG, Nakano EY, Zandonadi RP. Brief Version of Caffeine Expectancy Questionnaire in Brazil. Front Nutr 2021; 8:695385. [PMID: 34277689 PMCID: PMC8277974 DOI: 10.3389/fnut.2021.695385] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 06/08/2021] [Indexed: 12/24/2022] Open
Abstract
The use of extensive questionnaires has the limitation of filling time bias, related to the ability to focus and accurately respond to many items, justifying the necessity for a brief version. This study aimed to build a brief version of the Caffeine Expectancy Questionnaire in Brazil (B-CaffEQ-BR) composed of 21 items divided into seven factors, with as adequate consistency and reproducibility as the full version. Quantitative procedures using statistical modeling were applied using the CaffEQ-BR (full version) database keeping the Mean Absolute Error (MAE) (based on the full version) <0.5 and Cronbach's α and Intraclass Correlation Coefficient (ICC) ≥0.7. The expert panel (n = 3), in a blind design, evaluated the semantic structuring within the options indicated by previous statistical modeling until the agreement of the expert panel. The participants (n = 62), Brazilian adults who were regular caffeine consumers (175.8 ± 94.4 mg/day), of whom 62.9% were women, 33.1 ± 9.7 years, 24.5 ± 3.8 kg/m2, and 62.9% of whom self-identified as white, were asked to respond twice to the online questionnaire in 48-72 h. The first sample (n = 40) tested interobserver reproducibility with the double application of B-CaffEQ-BR. Another sample (n = 22) answered the CaffEQ-BR (full version) and B-CaffEQ-BR, and the last sample (n = 18) performed the reverse process. The B-CaffEQ-BR presented excellent internal consistency (Cronbach's α ≥ 0.729) and overall reproducibility (ICC ≥ 0.915) for the entire questionnaire and its seven factors. The B-CaffEQ-BR can be a valuable tool in caffeine research with the Brazilian adult population.
Collapse
Affiliation(s)
- Guilherme Falcão Mendes
- Department of Nutrition, School of Health Sciences, University of Brasilia (UnB), Brasilia, Brazil
| | | | - Eduardo Yoshio Nakano
- Department of Statistics, Central Institute of Sciences, University of Brasilia (UnB), Brasilia, Brazil
| | - Renata Puppin Zandonadi
- Department of Nutrition, School of Health Sciences, University of Brasilia (UnB), Brasilia, Brazil
| |
Collapse
|
9
|
Martins GL, Guilherme JPLF, Ferreira LHB, de Souza-Junior TP, Lancha AH. Caffeine and Exercise Performance: Possible Directions for Definitive Findings. Front Sports Act Living 2020; 2:574854. [PMID: 33345139 PMCID: PMC7739593 DOI: 10.3389/fspor.2020.574854] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Accepted: 11/17/2020] [Indexed: 01/01/2023] Open
Abstract
Caffeine is one of the most studied supplements in the world. Studies correlate its use to increased exercise performance in endurance activities, as well as its possible ergogenic effects for both intermittent and strength activities. Recent findings show that caffeine may increase or decrease exercise performance. These antagonist responses may occur even when using the same dosage and for individuals with the same characteristics, making it challenging to explain caffeine's impact and applicability. This review article provides an analytic look at studies involving the use of caffeine for human physical performance, and addresses factors that could influence the ergogenic effects of caffeine on different proposed activities. These factors subdivide into caffeine effects, daily habits, physiological factors, and genetic factors. Each variable has been focused on by discussions to research related to caffeine. A better understanding and control of these variables should be considered in future research into personalized nutritional strategies.
Collapse
Affiliation(s)
- Gabriel Loureiro Martins
- Laboratory of Applied Nutrition and Metabolism, School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil
| | | | - Luis Henrique Boiko Ferreira
- Research Group on Metabolism, Nutrition and Strength Training, Department of Physical Education, Federal University of Parana, Curitiba, Brazil
| | - Tácito Pessoa de Souza-Junior
- Research Group on Metabolism, Nutrition and Strength Training, Department of Physical Education, Federal University of Parana, Curitiba, Brazil
| | - Antonio Herbert Lancha
- Laboratory of Applied Nutrition and Metabolism, School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil
| |
Collapse
|
10
|
Functional and cognitive responses to caffeine intake in middle-aged women are dose depending. Behav Brain Res 2020; 397:112956. [PMID: 33035593 DOI: 10.1016/j.bbr.2020.112956] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 09/16/2020] [Accepted: 09/30/2020] [Indexed: 01/04/2023]
Abstract
Middle-aged women display many physiological and cognitive alterations resulting from aging and physical inactivity as well as other changes that occur as a function of menopause. Caffeine consumption is highest in this age with women having a particular greater sensitivity to caffeine than men. Its effects on functional and cognitive functions are controversial and seem to depend on the dose intake. This study aimed to assess the effect of low (100mg) and high (400mg) doses of caffeine consumption on cognitive (simple reaction time) and functional (upper and low body muscle endurance, aerobic endurance and functional mobility) performances. These performances were evaluated in 19 healthy middle-aged women by the 30-Second Chair Stand test for lower body muscle endurance, the 30sec Arm Curl Test for upper body muscle endurance, the 2-Minute Step test for aerobic endurance, The Timed Up and Go test for functional mobility and the simple reaction time test for reaction time, 60min after a treatment capsule intake (100mg caffeine/400mg caffeine/placebo). Low caffeine consumption significantly improved (p<.005) cognitive performance, while high caffeine consumption did not. However, the functional performance significantly improved (p<.05) after high caffeine consumption but not after low caffeine consumption. Except, the functional mobility performance significantly improved (p<.05) after both low and high caffeine consumption with better improvement (p<.05) after the high dose. In conclusion, low caffeine consumption improved cognitive performance and high caffeine consumption improved functional performance but the functional mobility improved after both low and high caffeine consumption in middleaged women.
Collapse
|
11
|
Grgic J, Pickering C, Bishop DJ, Del Coso J, Schoenfeld BJ, Tinsley GM, Pedisic Z. ADOR2A C Allele Carriers Exhibit Ergogenic Responses to Caffeine Supplementation. Nutrients 2020; 12:nu12030741. [PMID: 32168870 PMCID: PMC7146260 DOI: 10.3390/nu12030741] [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: 02/14/2020] [Revised: 03/03/2020] [Accepted: 03/09/2020] [Indexed: 12/20/2022] Open
Abstract
Caffeine’s ergogenic effects on exercise performance are generally explained by its ability to bind to adenosine receptors. ADORA2A is the gene that encodes A2A subtypes of adenosine receptors. It has been suggested that ADORA2A gene polymorphisms may be responsible for the inter-individual variations in the effects of caffeine on exercise performance. In the only study that explored the influence of variation in ADORA2A—in this case, a common polymorphism (rs5751876)—on the ergogenic effects of caffeine on exercise performance, C allele carriers were identified as “non-responders” to caffeine. To explore if C allele carriers are true “non-responders” to the ergogenic effects of caffeine, in this randomized, double-blind study, we examined the acute effects of caffeine ingestion among a sample consisting exclusively of ADORA2A C allele carriers. Twenty resistance-trained men identified as ADORA2A C allele carriers (CC/CT genotype) were tested on two occasions, following the ingestion of caffeine (3 mg/kg) and a placebo. Exercise performance was evaluated with movement velocity, power output, and muscle endurance during the bench press exercise, countermovement jump height, and power output during a Wingate test. Out of the 25 analyzed variables, caffeine was ergogenic in 21 (effect size range: 0.14 to 0.96). In conclusion, ADORA2A (rs5751876) C allele carriers exhibited ergogenic responses to caffeine ingestion, with the magnitude of improvements similar to what was previously reported in the literature among samples that were not genotype-specific. Therefore, individuals with the CT/CC genotype may still consider supplementing with caffeine for acute improvements in performance.
Collapse
Affiliation(s)
- Jozo Grgic
- Institute for Health and Sport (IHES), Victoria University, Melbourne 3011, Australia; (D.J.B.); (Z.P.)
- Correspondence:
| | - Craig Pickering
- Institute of Coaching and Performance, School of Sport and Wellbeing, University of Central Lancashire, Preston PR1 2HE, UK;
| | - David J. Bishop
- Institute for Health and Sport (IHES), Victoria University, Melbourne 3011, Australia; (D.J.B.); (Z.P.)
- School of Medical and Health Sciences, Edith Cowan University, Joondalup, Perth, WA 6027, Australia
| | - Juan Del Coso
- Centre for Sport Studies, Rey Juan Carlos University, C/Camino del Molino, s/n, 28943 Fuenlabrada, Spain;
| | | | - Grant M. Tinsley
- Energy Balance & Body Composition Laboratory, Department of Kinesiology & Sport Management, Texas Tech University, Lubbock, TX 79424, USA;
| | - Zeljko Pedisic
- Institute for Health and Sport (IHES), Victoria University, Melbourne 3011, Australia; (D.J.B.); (Z.P.)
| |
Collapse
|
12
|
Grgic J, Diaz-Lara FJ, Del Coso J, Duncan MJ, Tallis J, Pickering C, Schoenfeld BJ, Mikulic P. The Effects of Caffeine Ingestion on Measures of Rowing Performance: A Systematic Review and Meta-Analysis. Nutrients 2020; 12:nu12020434. [PMID: 32046330 PMCID: PMC7071243 DOI: 10.3390/nu12020434] [Citation(s) in RCA: 11] [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: 01/14/2020] [Revised: 01/28/2020] [Accepted: 02/05/2020] [Indexed: 11/16/2022] Open
Abstract
The purpose of this paper was to conduct a systematic review and a meta-analysis of studies examining the acute effects of caffeine ingestion on measures of rowing performance. Crossover and placebo-controlled experiments that investigated the effects of caffeine ingestion on measures of rowing performance were included. The PEDro checklist was used to assess the methodological quality of the included studies. Seven studies of good and excellent methodological quality were included. None of the included studies examined on-water rowing. The majority of studies that were included in the meta-analysis used a 2000m rowing distance with only one using 1000m distance. Results of the main meta-analysis indicated that caffeine enhances performance on a rowing ergometer compared to placebo with a mean difference of -4.1 s (95% confidence interval (CI): -6.4, -1.8 s). These values remained consistent in the analysis in which the study that used a 1000m distance was excluded (mean difference: -4.3 s; 95% CI: -6.9, -1.8 s). We also found a significant increase in mean power (mean difference: 5.7 W; 95% CI: 2.1, 9.3 W) and minute ventilation (mean difference: 3.4 L/min; 95% CI: 1.7, 5.1 L/min) following caffeine ingestion. No significant differences between caffeine and placebo were found for the rating of perceived exertion, oxygen consumption, respiratory exchange ratio, and heart rate. This meta-analysis found that acute caffeine ingestion improves 2000m rowing ergometer performance by ~4 s. Our results support the use of caffeine pre-exercise as an ergogenic aid for rowing performance.
Collapse
Affiliation(s)
- Jozo Grgic
- Institute for Health and Sport (IHES), Victoria University, Melbourne, 3011, Australia;
- Correspondence:
| | | | - Juan Del Coso
- Centre for Sport Studies, Rey Juan Carlos University, Fuenlabrada, 28943 Madrid, Spain;
| | - Michael J. Duncan
- Centre for Sport, Exercise and Life Sciences, Alison Gingell Building, Coventry University, Priory Street, Coventry CV1 5FB, UK; (M.J.D.); (J.T.)
| | - Jason Tallis
- Centre for Sport, Exercise and Life Sciences, Alison Gingell Building, Coventry University, Priory Street, Coventry CV1 5FB, UK; (M.J.D.); (J.T.)
| | - Craig Pickering
- Institute of Coaching and Performance, School of Sport and Wellbeing, University of Central Lancashire, Preston PR1 2HE, UK;
| | | | - Pavle Mikulic
- Faculty of Kinesiology, University of Zagreb, Zagreb 10000, Croatia;
| |
Collapse
|
13
|
Supplements and Nutritional Interventions to Augment High-Intensity Interval Training Physiological and Performance Adaptations-A Narrative Review. Nutrients 2020; 12:nu12020390. [PMID: 32024038 PMCID: PMC7071320 DOI: 10.3390/nu12020390] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Revised: 01/22/2020] [Accepted: 01/29/2020] [Indexed: 12/13/2022] Open
Abstract
High-intensity interval training (HIIT) involves short bursts of intense activity interspersed by periods of low-intensity exercise or rest. HIIT is a viable alternative to traditional continuous moderate-intensity endurance training to enhance maximal oxygen uptake and endurance performance. Combining nutritional strategies with HIIT may result in more favorable outcomes. The purpose of this narrative review is to highlight key dietary interventions that may augment adaptations to HIIT, including creatine monohydrate, caffeine, nitrate, sodium bicarbonate, beta-alanine, protein, and essential amino acids, as well as manipulating carbohydrate availability. Nutrient timing and potential sex differences are also discussed. Overall, sodium bicarbonate and nitrates show promise for enhancing HIIT adaptations and performance. Beta-alanine has the potential to increase training volume and intensity and improve HIIT adaptations. Caffeine and creatine have potential benefits, however, longer-term studies are lacking. Presently, there is a lack of evidence supporting high protein diets to augment HIIT. Low carbohydrate training enhances the upregulation of mitochondrial enzymes, however, there does not seem to be a performance advantage, and a periodized approach may be warranted. Lastly, potential sex differences suggest the need for future research to examine sex-specific nutritional strategies in response to HIIT.
Collapse
|
14
|
Ergogenic effects of caffeine on peak aerobic cycling power during the menstrual cycle. Eur J Nutr 2019; 59:2525-2534. [PMID: 31691019 DOI: 10.1007/s00394-019-02100-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 09/26/2019] [Indexed: 12/16/2022]
Abstract
PURPOSE Recent investigations have established that the ingestion of a moderate dose of caffeine (3-6 mg kg-1) can increase exercise and sports performance in women. However, it is unknown whether the ergogenicity of caffeine is similar during all phases of the menstrual cycle. The aim of this investigation was to determine the ergogenic effects of caffeine in three phases of the menstrual cycle. METHODS Thirteen well-trained eumenorrheic triathletes (age = 31 ± 6 years; body mass = 58.6 ± 7.8 kg) participated in a double-blind, cross-over, randomised experimental trial. In the (1) early follicular (EF); (2) preovulation (PO); (3) and mid luteal (ML) phases, participants either ingested a placebo (cellulose) or 3 mg kg-1 of caffeine in an opaque and unidentifiable capsule. After a 60-min wait for substance absorption, participants performed an incremental maximal cycle ergometer test until volitional fatigue (25 W/min) to assess peak aerobic cycling power (Wmax). RESULTS In comparison to the placebo, caffeine increased Wmax in the EF (4.13 ± 0.69 vs. 4.24 ± 0.71 W kg-1, Δ = 2.7 ± 3.3%, P = 0.01), in the PO (4.14 ± 0.70 vs. 4.27 ± 0.73 W kg-1, Δ = 3.3 ± 5.0%; P = 0.03) and in the ML (4.15 ± 0.69 vs. 4.29 ± 0.67 W kg-1, Δ = 3.6 ± 5.1%; P = 0.01) phases. The magnitude of the caffeine ergogenic effect was similar during all of the menstrual cycle phases (P = 0.85). CONCLUSION Caffeine increased peak aerobic cycling power in the early follicular, preovulatory, and mid luteal phases. Thus, the ingestion of 3 mg of caffeine per kg of body mass might be considered an ergogenic aid for eumenorrheic women during all three phases of the menstrual cycle.
Collapse
|
15
|
Abstract
In this paper, we review the effects of caffeine on muscle strength and provide suggestions for caffeine supplementation in powerlifting competitions. The currently available studies indicate that caffeine ingestion may enhance strength in two powerlifting competition events, the squat and the bench press. For the deadlift, the same might be expected even though studies directly using this event are lacking. Optimal doses of caffeine are likely in the range from 2 to 6 mg·kg−1, and are highly individual. When using caffeine-containing capsules, 60 minutes pre-exercise seems to be a good timing of caffeine consumption. For other sources such as caffeinated chewing gum, a shorter period (5 to 10 min) from consumption to the start of the exercise seems to be effective. For shorter duration powerlifting competitions (e.g., 2 hours), one pre-competition dose of caffeine could be sufficient for acute performance-enhancing effects that might be maintained across all three events. For longer duration competitions (with longer rest periods between one repetition maximum attempts), there might be a benefit to repeated dosing with caffeine; for example, ingesting smaller doses of caffeine before each attempt or event. During training, powerlifters may consider ingesting caffeine only before the training sessions with the highest intensity. This approach might eliminate the attenuation of caffeine’s effects associated with chronic caffeine ingestion and would help in maximizing performance benefits from acute caffeine ingestion at the competition. Nonetheless, withdrawal from caffeine (e.g., no caffeine intake seven days before competition) does not seem necessary and may have some indirect negative effects.
Collapse
|
16
|
Venier S, Grgic J, Mikulic P. Caffeinated Gel Ingestion Enhances Jump Performance, Muscle Strength, and Power in Trained Men. Nutrients 2019; 11:nu11040937. [PMID: 31027246 PMCID: PMC6520843 DOI: 10.3390/nu11040937] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 04/18/2019] [Accepted: 04/18/2019] [Indexed: 11/16/2022] Open
Abstract
We aimed to explore the effects of caffeinated gel ingestion on neuromuscular performance in resistance-trained men. The participants (n = 17; mean ± standard deviation (SD): age 23 ± 2 years, height 183 ± 5 cm, body mass 83 ± 11 kg) completed two testing conditions that involved ingesting a caffeinated gel (300 mg of caffeine) or placebo. The testing outcomes included: (1) vertical jump height in the squat jump (SJ) and countermovement jump (CMJ); (2) knee extension and flexion peak torque and average power at angular velocities of 60°·s-1 and 180°·s-1; (3) barbell velocity in the bench press with loads corresponding to 50%, 75%, and 90% of one-repetition maximum (1RM); and (4) peak power output in a test on a rowing ergometer. Compared to the placebo, caffeine improved: (1) SJ (p = 0.039; Cohen's d effect size (d) = 0.18; +2.9%) and CMJ height (p = 0.011; d = 0.18; +3.3%); (2) peak torque and average power in the knee extensors at both angular velocities (d ranged from 0.21 to 0.37; percent change from +3.5% to +6.9%), peak torque (p = 0.034; d = 0.24; +4.6%), and average power (p = 0.015; d = 0.32; +6.7%) at 60°·s-1 in the knee flexors; (3) barbell velocity at 50% 1RM (p = 0.021; d = 0.33; +3.5%), 75% 1RM (p < 0.001; d = 0.42; +5.4%), and 90% 1RM (p < 0.001; d = 0.59, +12.0%). We conclude that the ingestion of caffeinated gels may acutely improve vertical jump performance, strength, and power in resistance-trained men.
Collapse
Affiliation(s)
- Sandro Venier
- Faculty of Kinesiology, University of Zagreb, Zagreb 10000, Croatia.
| | - Jozo Grgic
- Institute for Health and Sport (IHES), Victoria University, Melbourne 3011, Australia.
| | - Pavle Mikulic
- Faculty of Kinesiology, University of Zagreb, Zagreb 10000, Croatia.
| |
Collapse
|
17
|
Grgic J, Grgic I, Pickering C, Schoenfeld BJ, Bishop DJ, Pedisic Z. Wake up and smell the coffee: caffeine supplementation and exercise performance—an umbrella review of 21 published meta-analyses. Br J Sports Med 2019; 54:681-688. [DOI: 10.1136/bjsports-2018-100278] [Citation(s) in RCA: 139] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/10/2019] [Indexed: 01/07/2023]
Abstract
ObjectiveTo systematically review, summarise and appraise findings of published meta-analyses that examined the effects of caffeine on exercise performance.DesignUmbrella review.Data sourcesTwelve databases.Eligibility criteria for selecting studiesMeta-analyses that examined the effects of caffeine ingestion on exercise performance.ResultsEleven reviews (with a total of 21 meta-analyses) were included, all being of moderate or high methodological quality (assessed using the Assessing the Methodological Quality of Systematic Reviews 2 checklist). In the meta-analyses, caffeine was ergogenic for aerobic endurance, muscle strength, muscle endurance, power, jumping performance and exercise speed. However, not all analyses provided a definite direction for the effect of caffeine when considering the 95% prediction interval. Using the Grading of Recommendations Assessment, Development and Evaluation criteria the quality of evidence was generally categorised as moderate (with some low to very low quality of evidence). Most individual studies included in the published meta-analyses were conducted among young men.Summary/conclusionSynthesis of the currently available meta-analyses suggest that caffeine ingestion improves exercise performance in a broad range of exercise tasks. Ergogenic effects of caffeine on muscle endurance, muscle strength, anaerobic power and aerobic endurance were substantiated by moderate quality of evidence coming from moderate-to-high quality systematic reviews. For other outcomes, we found moderate quality reviews that presented evidence of very low or low quality. It seems that the magnitude of the effect of caffeine is generally greater for aerobic as compared with anaerobic exercise. More primary studies should be conducted among women, middle-aged and older adults to improve the generalisability of these findings.
Collapse
|
18
|
Challenging the Myth of Non-Response to the Ergogenic Effects of Caffeine Ingestion on Exercise Performance. Nutrients 2019; 11:nu11040732. [PMID: 30934886 PMCID: PMC6521624 DOI: 10.3390/nu11040732] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 03/25/2019] [Accepted: 03/27/2019] [Indexed: 11/17/2022] Open
Abstract
The ergogenicity of caffeine on several exercise and sport situations is well-established. However, the extent of the ergogenic response to acute caffeine ingestion might greatly vary among individuals despite using the same dosage and timing. The existence of one or several individuals that obtained minimal ergogenic effects or even slightly ergolytic effects after caffeine intake (i.e., non-responders) has been reported in several previous investigations. Nevertheless, the concept non-responding to caffeine, in terms of physical performance, relies on investigations based on the measurement of one performance variable obtained once. Recently it has been suggested that correct identification of the individual ergogenic effect induced by caffeine intake requires the repeated measurement of physical performance in identical caffeine–placebo comparisons. In this communication, we present data from an investigation where the ergogenic effect of acute caffeine intake (3 mg/kg) was measured eight times over a placebo in the same individuals and under the same conditions by an incremental cycling test to volitional fatigue and an adapted version of the Wingate cycling test. The ergogenic response to caffeine varied from 9% to 1% among individuals, but all participants increased both cycling power in the incremental test and Wingate mean power at least three to eight times out of eight the caffeine–placebo comparisons. These data expand the suggestion of a minimal occurrence of caffeine non-responders because it shows that all individuals responded to caffeine when caffeine is compared to a placebo on multiple and repeated testing sessions.
Collapse
|
19
|
Cornelis MC. The Impact of Caffeine and Coffee on Human Health. Nutrients 2019; 11:nu11020416. [PMID: 30781466 PMCID: PMC6413001 DOI: 10.3390/nu11020416] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 02/13/2019] [Indexed: 12/17/2022] Open
Affiliation(s)
- Marilyn C Cornelis
- Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
| |
Collapse
|
20
|
Response to "Are There Non-Responders to the Ergogenic 3 Effects of Caffeine Ingestion on Exercise Performance?". Nutrients 2018; 10:nu10111752. [PMID: 30428627 PMCID: PMC6266606 DOI: 10.3390/nu10111752] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 11/09/2018] [Indexed: 12/03/2022] Open
|