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Cited by 71Coffee research and impactsMuscle metabolism and nutritionSports Performance and Training

Does caffeine added to carbohydrate provide additional ergogenic benefit for endurance?

Conger, Scott A., Warren, Gordon L., Hardy, Michelle A., Millard-Stafford, Mindy L.·2011·International Journal of Sport Nutrition and Exercise Metabolism
DOI 10.1123/ijsnem.21.1.71
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Abstract

CONTEXT: Carbohydrate (CHO) and caffeine (CAF) both improve endurance performance. PURPOSE: To determine by systematic literature review coupled with meta-analysis whether CAF ingested with CHO (CHO+CAF) improves endurance performance more than CHO alone. METHODS: Databases were searched using the keywords caffeine, endurance, exercise, carbohydrate, and performance. Criteria for inclusion were studies that used human subjects performing an endurance-exercise performance task and included both a CHO and CHO+CAF condition. Effect sizes (ESs) were calculated as the standardized mean difference. RESULTS: Twenty-one studies met the criteria for analysis. ESs for individual studies ranged from -0.08 (trivial effect favoring CHO) to 1.01 (large effect favoring CHO+CAF). The overall ES equaled 0.26 (95% CI 0.15-0.38, p < .001), indicating that CHO+CAF provides a small but significant performance benefit over CHO. ES was not significantly (p > .05) related to CAF dose, exercise duration, or performance-assessment method. To determine whether ES of CHO+CAF vs. CHO was different than CAF compared with water (placebo), a subgroup meta-analysis compared 36 CAF vs. placebo studies against the 21 CHO+CAF vs. CHO studies. The overall ES for the former group of studies (ES = 0.51, 95% CI 0.40-0.61) was nearly 2-fold greater than in CHO+CAF vs. CHO studies (p = .006). CONCLUSIONS: CHO+CAF ingestion provides a significant but small effect to improve endurance performance compared with CHO alone. However, the magnitude of the performance benefit that CAF provides is less when added to CHO than when added to placebo.

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  • A meta-analysis of caffeine supplementation and endurance performance found that the margin of improvement when caffeine was consumed in addition to CHO was significantly reduced (but still worthwhile) compared to water placebo (mean effect sizes = 0.26 vs. 0.52, p = .006).

    “a meta-analysis of a heterogeneous group of studies of caffeine supplementation and endurance performance (Conger et al., 2011) found that the margin of improvement when caffeine was consumed in addition to CHO was significantly reduced (but still worthwhile) in comparison to scenarios involving a water placebo (mean effect sizes = 0.26 vs. 0.52, p = .006).”

    From Contemporary Nutrition Strategies to Optimize Performance in Distance Runners and Race Walkers (2019) · cites this paper as Conger et al., 2011

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Authors
Conger, S. A., Warren, G. L., Hardy, M. A., & Millard-Stafford, M. L.
Affiliations
Georgia Institute of Technology (US)
ORCID
Venue
International Journal of Sport Nutrition and Exercise Metabolism
Publisher
Human Kinetics
Published
2011-02
Volume
21
Issue
1
Pages
71-84
ISSN
  • 1526-484X (ISSN-L)
  • 1543-2742
DOI
10.1123/ijsnem.21.1.71
OpenAlex
W2107437117
Cited by
71
References
84
Citations by year
2025: 2 · 2024: 1 · 2023: 3 · 2022: 4 · 2021: 5 · 2020: 4 · 2019: 8 · 2018: 4 · 2017: 3 · 2016: 4 · 2015: 6 · 2014: 8 · 2013: 6 · 2012: 8
FWCI
5.85
Type
journal article
Language
en
Open access
closed
Locations
  • International Journal of Sport Nutrition and Exercise Metabolism (publishedVersion)
  • PubMed (publishedVersion)
Funders
Coca-Cola Foundation
Topics
  • Health Sciences › Medicine › Pharmacology › Coffee research and impacts
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Cell Biology › Muscle metabolism and nutrition
  • Health Sciences › Medicine › Orthopedics and Sports Medicine › Sports Performance and Training
Keywords
caffeine, carbohydrate intake, endurance performance, ergogenic aids, placebo effect, caffeine dose, exercise duration
MeSH terms
Caffeine, Central Nervous System Agents, Dietary Carbohydrates, Humans, Physical Endurance, Exercise, Muscle Fatigue

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