Exercise and Sport Science Department, University of Wisconsin-La Crosse, La Crosse, Wisconsin, USA.
J Strength Cond Res. 2010 Jan;24(1):79-87. doi: 10.1519/JSC.0b013e3181c63bd5.
The dipeptide carnosine has been shown to contribute to the buffer capacity of hydrogen ions (H) during intense exercise. Increasing skeletal muscle carnosine levels through beta-alanine (BA) supplementation has been shown to maintain acid-base balance, delay fatigue, and improve exercise performance. We designed this study to examine the effect of 5 weeks of BA supplementation on repeat high-intensity sprint performance. Nineteen, physically active, college men were divided into 2 groups (control [C], n = 10 or BA, n = 9). We performed double-blind placebo-controlled study where subjects ingested 4 g per day during the first week and 6 g per day over the next 4 weeks of a placebo (rice flour) or a BA supplement. Subjects completed 2 sets of 5 5-second sprints with 45-second recovery separated by 2 minutes of active recovery. All tests were conducted on a non-motorized treadmill against a resistance of 15% of the participant's body weight. We recorded horizontal power (HP) of the running sprint. Post-exercise capillary blood samples were analyzed for lactate to determine the metabolic demands. There were no significant between-group differences (p > 0.05) in HPpeak or HPmean for the repeat sprint protocol. No significant between-group differences were found for performance decrement (% fatigue) for HPpeak or HPmean. In addition, no significant interactions were observed. Post-exercise blood lactate values were similar pre and post supplementation in both groups. The results of this study clearly indicate that 5 weeks of BA supplementation provides no benefit for repeat sprint performance.
二肽肌肽已被证明有助于在剧烈运动期间缓冲氢离子 (H)。通过β-丙氨酸 (BA) 补充来增加骨骼肌肌肽水平已被证明可以维持酸碱平衡、延迟疲劳和提高运动表现。我们设计了这项研究来检验 5 周 BA 补充对重复高强度冲刺表现的影响。19 名身体活跃的大学生被分为 2 组（对照组 [C]，n = 10 或 BA，n = 9）。我们进行了双盲安慰剂对照研究，其中受试者在第一周每天摄入 4 克，接下来的 4 周每天摄入 6 克安慰剂（米粉）或 BA 补充剂。受试者完成了 2 组 5 个 5 秒冲刺，每组之间有 45 秒的恢复期，恢复期为 2 分钟主动恢复期。所有测试均在非电动跑步机上进行，阻力为参与者体重的 15%。我们记录了跑步冲刺的水平功率 (HP)。运动后毛细血管血样用于分析乳酸以确定代谢需求。重复冲刺方案中 HPpeak 或 HPmean 的组间差异无统计学意义 (p > 0.05)。HPpeak 或 HPmean 的性能下降（%疲劳）在组间也没有发现显著差异。此外，没有观察到显著的相互作用。两组的运动后血乳酸值在补充前后相似。这项研究的结果清楚地表明，5 周的 BA 补充对重复冲刺表现没有益处。
