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Review
. 2024 Dec;21(1):2323919.
doi: 10.1080/15502783.2024.2323919. Epub 2024 Mar 11.

Common questions and misconceptions about caffeine supplementation: what does the scientific evidence really show?

Jose Antonio  1 , Daniel E Newmire  2 , Jeffrey R Stout  3 , Brandi Antonio  3 , Maureen Gibbons  4 , Lonnie M Lowery  5   6 , Joseph Harper  6 , Darryn Willoughby  7 , Cassandra Evans  1 , Dawn Anderson  8 , Erica Goldstein  9 , Jose Rojas  10   11 , Matías Monsalves-Álvarez  12   13 , Scott C Forbes  14 , Jose Gomez Lopez  13 , Tim Ziegenfuss  15 , Blake D Moulding  16 , Darren Candow  16 , Michael Sagner  17 , Shawn M Arent  18
Affiliations
Review

Common questions and misconceptions about caffeine supplementation: what does the scientific evidence really show?

Jose Antonio et al. J Int Soc Sports Nutr. 2024 Dec.

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.

Keywords: Ergogenic aid; exercise; performance; supplement.

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Conflict of interest statement

JA is the CEO of the International Society of Sports Nutrition (ISSN), a 501c3 academic non-profit. The ISSN receives grants from companies that sell, market, and manufacture caffeine-containing sports nutrition products. JRS has no conflict of interest related to this manuscript regarding financial or business interests. Over the past 25 years, he has received grants and contracts to research dietary supplements, served as a paid consultant for industry, and received honoraria for speaking at conferences and writing lay articles about sports nutrition ingredients and topics. TNZ has no conflict in terms of financial or business interests related to the topic of this publication. He has received funding from dietary supplement companies for research, honoraria for speaking at conferences, and fees for writing articles and consulting. SMA has received grant funding from the US Department of Defense and from industry for research on caffeine and caffeine-related substances. LML is President of Nutrition, Exercise, and Wellness Associates, which receives financial support from educational, food, and/or dietary supplement companies that produce, market, distribute, or sell coffee-related products. He has received sports nutrition-related grants, as well as financial compensation for speaking at conferences and writing lay articles about sports nutrition. DC, SF, BA, JGL, MMA, CE, JR, MG, EG, JH, DA, BDM, and MS have no conflicts to declare.

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