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Cited by 20Sports Performance and TrainingThermoregulation and physiological responsesMuscle metabolism and nutrition

A combination of amino acids and caffeine enhances sprint running capacity in a hot, hypoxic environment

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Eaton, Tom R., Potter, Aaron, Billaut, François, Panchuk, Derek, Pyne, David B., Gore, Christopher J., Chen, Ting-Ting, McQuade, Leon +1 more·2016·International Journal of Sport Nutrition and Exercise Metabolism
DOI 10.1123/ijsnem.2015-0108
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Abstract

Heat and hypoxia exacerbate central nervous system (CNS) fatigue. We therefore investigated whether essential amino acid (EAA) and caffeine ingestion attenuates CNS fatigue in a simulated team sport-specific running protocol in a hot, hypoxic environment. Subelite male team sport athletes (n = 8) performed a repeat sprint running protocol on a nonmotorized treadmill in an extreme environment on 4 separate occasions. Participants ingested one of four supplements: a double placebo, 3 mg.kg-1 body mass of caffeine + placebo, 2 x 7 g EAA (Musashi Create)+placebo, or caffeine + EAA before each exercise session using a randomized, double-blind crossover design. Electromyography (EMG) activity and quadriceps evoked responses to magnetic stimulation were assessed from the dominant leg at preexercise, halftime, and postexercise. Central activation ratio (CAR) was used to quantify completeness of quadriceps activation. Oxygenation of the prefrontal cortex was measured via near-infrared spectroscopy. Mean sprint work was higher (M = 174 J, 95% CI [23, 324], p < .05, d = 0.30; effect size, likely beneficial) in the caffeine + EAA condition versus EAAs alone. The decline in EMG activity was less (M = 13%, 95% CI [0, 26]; p < .01, d = 0.58, likely beneficial) in caffeine + EAA versus EAA alone. Similarly, the pre- to postexercise decrement in CAR was significantly less (M = -2.7%, 95% CI [0.4, 5.4]; p < .05, d = 0.50, likely beneficial) when caffeine + EAA were ingested compared with placebo. Cerebral oxygenation was lower (M = -5.6%, 95% CI [1.0, 10.1]; p < .01, d = 0.60, very likely beneficial) in the caffeine + EAA condition compared with LNAA alone. Co-ingestion of caffeine and EAA appears to maintain muscle activation and central drive, with a small improvement in running performance.

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  • An investigation of 91 publications defining participants as 'elite' or 'expert' found the term encompassed athletes from national-level competitions to medalists at major international competition.

    “An investigation examining 91 publications, which defined their participants as either “elite” or “expert” across a range of sports, found that the range of this term encompassed athletes participating in national-level competitions up to athletes winning medals at major international competition.2”

    From Defining Training and Performance Caliber: A Participant Classification Framework (2022) · cites this paper as [2]

  • Swann and colleagues proposed 5 criteria to assess an athlete's ability and used them to differentiate semi-elite from world-class.

    “Swann and colleagues proposed that 5 criteria should be used to assess an athlete's ability: (1) highest performance standard, (2) level of success, (3) years of experience, (4) competitiveness of the sport within the athlete's country, and (5) global competitiveness of the sport, with responses used in a mathematical equation to differentiate a “semi-elite” athlete from a “world-class” athlete.”

    From Defining Training and Performance Caliber: A Participant Classification Framework (2022) · cites this paper as [2]

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  1. Doherty, M. and Smith, P.M. (2004). Effects of caffeine ingestion on exercise testing: A meta-analysis. International Journal of Sport Nutrition & Exercise Metabolism 14: 626-646: doi: http://0- search.ebscohost.com.library.vu.edu.au/login.aspx?direct=true&db=s3h&AN=15717000&site=e host-live
  2. Schneiker, K.T., Bishop, D., Dawson, B., and Hackett, L.P. (2006). Effects of caffeine on prolonged intermittent-sprint ability in team-sport athletes. Med Sci Sports Exerc 38: 578-85: doi: 10.1249/01.mss.0000188449.18968. · DOI

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Authors
Eaton, T. R., Potter, A., Billaut, F., Panchuk, D., Pyne, D. B., Gore, C. J., Chen, T.-T., McQuade, L., & Stepto, N. K.
Affiliations
  • Victoria University (AU)
  • Université Laval (CA)
Corresponding author
Stepto, Nigel K.
ORCID
Venue
International Journal of Sport Nutrition and Exercise Metabolism
Publisher
Human Kinetics
Published
2016-02
Volume
26
Issue
1
Pages
33-45
ISSN
  • 1526-484X (ISSN-L)
  • 1543-2742
DOI
10.1123/ijsnem.2015-0108
OpenAlex
W2286458682
Cited by
20
References
35
Citations by year
2025: 1 · 2024: 2 · 2022: 1 · 2021: 5 · 2020: 3 · 2019: 1 · 2018: 5 · 2016: 2
FWCI
2.40
Type
journal article
Language
en
Open access
Locations
  • International Journal of Sport Nutrition and Exercise Metabolism (publishedVersion)
  • PubMed (publishedVersion)
  • Victoria University Research Repository (Victoria University) (submittedVersion)
  • ResearchOnline - JCU (James Cook University) (submittedVersion)
  • University of Canberra Research Portal (submittedVersion)
Funders
  • Australian Government
  • Australian Sports Commission
  • National Science Council
  • Australian Institute of Sport
Topics
  • Health Sciences › Medicine › Orthopedics and Sports Medicine › Sports Performance and Training
  • Health Sciences › Medicine › Physiology › Thermoregulation and physiological responses
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Cell Biology › Muscle metabolism and nutrition
Keywords
caffeine, essential amino acids, central fatigue, heat stress, hypoxia, sprinting, team sport athletes, muscle activation, central activation ratio, prefrontal cortex oxygenation, dietary supplementation, exercise performance
MeSH terms
Amino Acids, Caffeine, Double-Blind Method, Electromyography, Exercise Test, Football, Hot Temperature, Humans, Male, Running, Cross-Over Studies, Muscle Fatigue, Dietary Supplements, Quadriceps Muscle, Athletic Performance, Young Adult, Athletes, Sports Nutritional Physiological Phenomena

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