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Cited by 80Thermoregulation and physiological responsesCoffee research and impactsExercise and Physiological Responses

No effect of nutritional adenosine receptor antagonists on exercise performance in the heat

Cheuvront, Samuel N., Ely, Brett R., Kenefick, Robert W., Michniak-Kohn, Bozena B., Rood, Jennifer C., Sawka, Michael N.·2009·American Journal of Physiology-Regulatory, Integrative and Comparative Physiology
DOI 10.1152/ajpregu.90812.2008
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Abstract

Nutritional adenosine receptor antagonists can enhance endurance exercise performance in temperate environments, but their efficacy during heat stress is not well understood. This double-blinded, placebo-controlled study compared the effects of an acute dose of caffeine or quercetin on endurance exercise performance during compensable heat stress (40°C, 20–30% rh). On each of three occasions, 10 healthy men each performed 30-min of cycle ergometry at 50% V̇o2peak followed by a 15-min performance time trial after receiving either placebo ( Group P), caffeine ( Group C; 9 mg/kg), or quercetin ( Group Q; 2,000 mg). Serial blood samples, physiological (heart rate, rectal, and mean skin body temperatures), perceptual (ratings of perceived exertion, pain, thermal comfort, motivation), and exercise performance measures (total work and pacing strategy) were made. Supplementation with caffeine and quercetin increased preexercise blood concentrations of caffeine (55.62 ± 4.77 μM) and quercetin (4.76 ± 2.56 μM) above their in vitro inhibition constants for adenosine receptors. No treatment effects were observed for any physiological or perceptual measures, with the exception of elevated rectal body temperatures (0.20–0.30°C; P < 0.05) for Group C vs. Groups Q and P. Supplementation did not affect total work performed ( Groups P: 153.5 ± 28.3, C: 157.3 ± 28.9, and Q: 151.1 ± 31.6 kJ; P > 0.05) or the self-selected pacing strategy employed. These findings indicate that the nutritional adenosine receptor antagonists caffeine and quercetin do not enhance endurance exercise performance during compensable heat stress.

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Crossref · 10.1152/ajpregu.90812.2008

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  • In a study of healthy men, compared with placebo, single doses of 9 mg/kg body weight caffeine consumed after four days of caffeine abstinence increased core rectal body temperature by 0.20-0.30 degrees Celsius, but not skin temperature.

    “Compared with placebo, single doses of 9 mg/kg bw caffeine consumed after four days of caffeine abstinence also increased core (rectal) body temperature (by 0.20-0.30C), but not skin temperature, in 10 healthy men”

    From Scientific Opinion on the safety of caffeine (2015) · cites this paper as Cheuvront et al., 2009

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Authors
Cheuvront, S. N., Ely, B. R., Kenefick, R. W., Michniak-Kohn, B. B., Rood, J. C., & Sawka, M. N.
Affiliations
  • U.S. Army Research Institute of Environmental Medicine (US)
  • Pennington Biomedical Research Center (US)
ORCID
Venue
American Journal of Physiology-Regulatory, Integrative and Comparative Physiology
Publisher
American Physiological Society
Published
2009-02
Volume
296
Issue
2
Pages
R394-R401
ISSN
  • 0363-6119 (ISSN-L)
  • 1522-1490
DOI
10.1152/ajpregu.90812.2008
OpenAlex
W2133370737
Cited by
80
References
60
Citations by year
2025: 1 · 2024: 4 · 2023: 3 · 2022: 4 · 2021: 5 · 2020: 2 · 2019: 4 · 2018: 4 · 2017: 2 · 2016: 4 · 2015: 3 · 2014: 10 · 2013: 9 · 2012: 5
FWCI
4.52
Type
journal article
Language
en
Open access
closed
Locations
  • American Journal of Physiology-Regulatory, Integrative and Comparative Physiology (publishedVersion)
  • Defense Technical Information Center (DTIC) (submittedVersion)
Funders
Defense Advanced Research Projects Agency
Topics
  • Health Sciences › Medicine › Physiology › Thermoregulation and physiological responses
  • Health Sciences › Medicine › Pharmacology › Coffee research and impacts
  • Health Sciences › Medicine › Rehabilitation › Exercise and Physiological Responses
Keywords
adenosine receptor antagonists, caffeine, quercetin, heat stress, endurance exercise performance, rectal temperature, pacing strategy, exercise thermoregulation, dietary supplementation

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