Sport Coaching College, Beijing Sport University, Beijing 100084, China.
Institute of Population Research, Peking University, Beijing 100871, China.
Nutrients. 2024 May 8;16(10):1421. doi: 10.3390/nu16101421.
Caffeine has attracted significant attention from researchers in the sports field due to its well-documented ergogenic effects across various athletic disciplines. As research on caffeine continues to progress, there has been a growing emphasis on evaluating caffeine dosage and administration methods. However, investigations into the optimal timing of caffeine intake remain limited. Therefore, this narrative review aimed to assess the ergogenic effects of caffeine administration at different times during the morning (06:00 to 10:00) and evening (16:00 to 21:00). The review findings suggest that circadian rhythms play a substantial role in influencing sports performance, potentially contributing to a decline in morning performance. Caffeine administration has demonstrated effectiveness in mitigating this phenomenon, resulting in ergogenic effects and performance enhancement, even comparable to nighttime levels. While the specific mechanisms by which caffeine regulates circadian rhythms and influences sports performance remain unclear, this review also explores the mechanisms underlying caffeine's ergogenic effects, including the adenosine receptor blockade, increased muscle calcium release, and modulation of catecholamines. Additionally, the narrative review underscores caffeine's indirect impact on circadian rhythms by enhancing responsiveness to light-induced phase shifts. Although the precise mechanisms through which caffeine improves morning performance declines via circadian rhythm regulation necessitate further investigations, it is noteworthy that the timing of caffeine administration significantly affects its ergogenic effects during exercise. This emphasizes the importance of considering caffeine intake timing in future research endeavors to optimize its ergogenic potential and elucidate its mechanisms.
咖啡因由于在各种运动项目中具有良好的功效而引起了运动领域研究人员的极大关注。随着对咖啡因的研究不断深入，人们越来越关注评估咖啡因的剂量和给药方法。然而，关于咖啡因摄入最佳时间的研究仍然有限。因此，本叙述性综述旨在评估在早晨（6:00 至 10:00）和晚上（16:00 至 21:00）不同时间点给予咖啡因的功效。综述结果表明，昼夜节律对影响运动表现起着重要作用，可能导致早晨表现下降。咖啡因给药已被证明能有效缓解这种现象，从而产生功效并提高运动表现，甚至可与夜间水平相媲美。虽然咖啡因调节昼夜节律和影响运动表现的具体机制尚不清楚，但本综述还探讨了咖啡因产生功效的机制，包括腺苷受体阻断、增加肌肉钙释放和儿茶酚胺的调节。此外，叙述性综述强调了咖啡因通过增强对光诱导的相位转变的反应性来间接影响昼夜节律。虽然通过调节昼夜节律来提高早晨表现下降所需的咖啡因改善机制需要进一步研究，但值得注意的是，咖啡因给药的时间会显著影响其在运动中的功效。这强调了在未来的研究中考虑咖啡因摄入时间以优化其功效并阐明其机制的重要性。
