Caffeine and Exercise: What Next?

Abstract

Caffeine is a widely utilized performance-enhancing supplement used by athletes and non-athletes alike. In recent years, a number of meta-analyses have demonstrated that caffeine’s ergogenic effects on exercise performance are well-established and well-replicated, appearing consistent across a broad range of exercise modalities. As such, it is clear that caffeine is an ergogenic aid—but can we further explore the context of this ergogenic aid in order to better inform practice? We propose that future research should aim to better understand the nuances of caffeine use within sport and exercise. Here, we propose a number of areas for exploration within future caffeine research. These include an understanding of the effects of training status, habitual caffeine use, time of day, age, and sex on caffeine ergogenicity, as well as further insight into the modifying effects of genotype. We also propose that a better understanding of the wider, non-direct effects of caffeine on exercise, such as how it modifies sleep, anxiety, and post-exercise recovery, will ensure athletes can maximize the performance benefits of caffeine supplementation during both training and competition. Whilst not exhaustive, we hope that the questions provided within this manuscript will prompt researchers to explore areas with the potential to have a large impact on caffeine use in the future.

Isolated effects of caffeine and sodium bicarbonate ingestion on performance in the Yo-Yo test: A systematic review and meta-analysis

“…Future studies are needed to explore optimal doses of caffeine and sodium bicarbonate that have the largest effect on performance while producing the least sideeffects. 48 In addition to doses, future work is need on the optimal timing of ingestion. Timing of ingestion may be especially important to investigate when it comes to sodium bicarbonate given that there is very large inter-individual variability in responses to sodium bicarbonate ingestion, 9,39,40 and the timing of ingestion is also affected by the mode of delivery.…”

CYP1A2 genotype and acute effects of caffeine on resistance exercise, jumping, and sprinting performance

“…Studies that have reported individual participant data suggest that some individuals experience an increase in performance following caffeine ingestion, whereas others do not [4][5][6]. In order to develop more effective guidelines for caffeine supplementation in sport and exercise settings, the scientific focus has recently been placed on examining and understanding the reasons for the between-individual variation in responses [4,7].…”

ADORA2A C Allele Carriers Exhibit Ergogenic Responses to Caffeine Supplementation

“…Specifically, individuals with the AA genotype are commonly classified as "fast caffeine metabolizers", whereas C allele carriers (AC/CC genotypes) are considered to be "slow caffeine metabolizers", respectively [13]. The influence of CYP1A2 (rs762551) on the acute effects of caffeine supplementation on exercise performance has been explored in several studies [14][15][16][17][18][19][20][21][22][23]. However, the evidence in these studies remains inconsistent, with some reporting no effect of the polymorphism on the ergogenic effects of caffeine supplementation and others showing a modifying effect, but in different directions [14][15][16][17][18][19][20][21][22][23].…”