Author(s): MATSUMURA, T., TOMOO, K.1,2, TERADA, M.1, HASHIMOTO, T.1, Institution: RITSUMEIKAN UNIVERSITY, Country: JAPAN, Abstract-ID: 1180

INTRODUCTION:
Caffeine at doses ranging from 3 to 6 mg/kg (i.e., ~moderate doses) has been shown to acutely enhance jump performance (1,2) that is an important component of many sports. Conversely, there is growing interest in the impact of low doses of caffeine (i.e., ≤3 mg/kg) as not only an effective but also a safe and feasible ergogenic strategy (3,4), considering the widespread use of caffeine in competitive sports. However, the potential concern of “whether caffeine exhibits dose-dependent ergogenic effects” arises when considering the use of lower doses of caffeine. Our recent work demonstrated that within the range of 1–6 mg/kg, a very low dose (1 mg/kg) of caffeine increased countermovement jump (CMJ) height in a dose-independent manner, although its effect on squat jump (SJ) height was not significant (4). Despite this, the effect size was nearly equivalent to previous meta-analyses (1,2). This study aimed to examine the acute effect of caffeine on jump performance in athletes and its dose-response relationship, with the intention of exploring the potential use of lower caffeine doses.
METHODS:
A literature search was conducted on PubMed, the Cochrane Library, and Web of Science to identify studies that investigated the acute effect of caffeine on single vertical jump performance in athletic populations. Studies with level 2 evidence or higher were included if vertical jump height were assessed in caffeine and placebo conditions with CMJ, CMJ with arm swing (CMJA), as well as SJ. Data pertaining to study methodology and vertical jump height were systematically extracted. Separate random effects meta-analyses were performed for vertical jump height. Meta-regression was employed to examine the relationships between caffeine dose and vertical jump height.
RESULTS:
Twenty-four studies were included. Meta-analysis showed that caffeine doses ranging from 1 to 6 mg/kg caffeine exhibited significantly higher pooled jump height in CMJ (P < 0.001, g = 0.31 [95%CI: 0.16 to 0.46]) and SJ (P = 0.005, g = 0.22 [95%CI: 0.08 to 0.36]) compared to the placebo. However, no significant difference was observed in CMJA (P = 0.101, g = 0.13 [95%CI: -0.03 to 0.29]). Meta-regression revealed no significant linear relationships between caffeine dose and the ergogenic effect of caffeine on jump height in any testing forms of jump performance (CMJ: P = 0.440, CMJA: P = 0.642, SJ: P = 0.793).
CONCLUSION:
Caffeine has an ergogenic effect on jump performance in athletes, but this effect does not exhibit a dose-response relationship within the range of very low to moderate doses. These findings indicate the applicability of even lower doses (i.e., 1–3 mg/kg) of caffeine as an ergogenic aid for jump performance. Increasing the acute dose of caffeine may not guarantee a proportional increase in ergogenic effects on jump performance.
REFERENCES:
1. Grgic et al. J Int Soc Sports Nutr. 2018
2. Salinero et al. Res Sports Med. 2019
3. Grgic. Nutr Food Sci. 2023
4. Matsumura et al. Int J Sport Nutr Exerc Metab. 2023