The potential ergogenic benefits of caffeine (CAF) are well known within the athletic community, often leading to its use in adolescent swimming cohorts to enhance their performance. However, it has previously been reported that CAF has sleep-disturbing effects, which could be detrimental to performance over consecutive days in multiday competitions. Moreover, the effects that evening CAF ingestion has on sleep, side effects, and next-day performances are yet to be researched in trained adolescents. In a double-blind, randomized, crossover design, eight national-level swimmers (age: 18 ± 1 years, height: 1.76 ± 0.06 cm, body mass [BM]: 69.4 ± 6.4 kg) ingested a capsule containing 3 mg/kg BM CAF or a placebo 60 min before an evening 100-m swimming time trial. The next morning, sleep was analyzed (Core Consensus Sleep Diary) and 100-m time trials were repeated. Side effects were analyzed via visual analog scales throughout the study. No differences were found for swimming performance (p = .911) in the evening (CAF: 59.5 ± 7.8 s, placebo: 59.9 ± 7.9 s, g = 0.06) or morning (CAF: 59.7 ± 7.7 s, placebo: 60.2 ± 7.9 s, g = 0.07). In addition, no group differences were found for any subjective side effects (e.g., anxiety: p = .468, tachycardia: p = .859, alertness: p = .959) or sleep parameters (e.g., sleep latency: p = .395, total sleep time: p = .574). These results question the use of a standardized 3 mg/kg BM CAF ingestion strategy for 100-m swimming time trials in trained adolescents, although objective measures may be needed to confirm that CAF does not affect sleep within this cohort.

咖啡因 (CAF) 的潜在增效益处在运动界众所周知，通常导致其在青少年游泳队列中用于提高他们的表现。然而，此前曾有报道称，CAF 具有干扰睡眠的作用，这可能不利于连续几天在多日比赛中的表现。此外，晚上摄入 CAF 对睡眠、副作用和第二天表现的影响还有待在受过训练的青少年中进行研究。在一项双盲、随机、交叉设计中，八名国家级游泳运动员（年龄：18 ± 1 岁，身高：1.76 ± 0.06 cm，体重 [BM]：69.4 ± 6.4 kg）摄入了一个含有 3 mg/kg 的胶囊在晚上 100 米游泳计时赛前 60 分钟使用 BM CAF 或安慰剂。第二天早上，分析睡眠（核心共识睡眠日记）并重复 100 米计时试验。在整个研究过程中通过视觉模拟量表分析副作用。游泳表现没有发现差异（p  = .911）在晚上（CAF：59.5 ± 7.8 s，安慰剂：59.9 ± 7.9 s，g  = 0.06）或早上（CAF：59.7 ± 7.7 s，安慰剂：60.2 ± 7.9 s，g  = 0.07）。此外，没有发现任何主观副作用（例如，焦虑：p  = .468、心动过速：p  = .859、警觉性：p  = .959）或睡眠参数（例如，睡眠潜伏期：p  = .395）的组间差异，总睡眠时间：p  = .574）。这些结果质疑在训练有素的青少年中使用标准化的 3 mg/kg BM CAF 摄入策略进行 100 米游泳时间试验，尽管可能需要客观的措施来确认 CAF 不影响该队列中的睡眠。