School of Human Life Sciences, University of Tasmania, Launceston, Tasmania, Australia.
Med Sci Sports Exerc. 2012 Aug;44(8):1545-51. doi: 10.1249/MSS.0b013e31824cc08d.
The purpose of this study was to investigate the effects of 28 d of β-alanine supplementation on 4-min cycling time trial performance and to determine whether there was an additive effect of combined β-alanine and sodium bicarbonate (NaHCO3) supplementation on high-intensity cycling performance.
Fourteen highly trained cyclists (mean ± SD: age = 25.4 ± 7.2 yr, mass = 71.1 ± 7.1 kg, V˙O(2max) = 66.6 ± 5.7 mL·kg·min) supplemented for 28 d with β-alanine (65 mg·kg body mass each day) or placebo. A maximal 4-min bout of cycling was performed before supplementation (baseline) and twice after supplementation: after ingestion of NaHCO3 (300 mg·kg body mass) and ingestion of a placebo using a randomized crossover design with 2 d between trials. Blood pH and HCO3 concentration were determined before loading (postsupplementation trials) and at pretest and posttest.
In the acute NaHCO3 loading trials, blood pH and HCO3 were elevated from before loading to pretest, and the magnitude of the change in HCO3 from pretest to posttest was significantly greater compared with the acute placebo loading trial (P < 0.001). Average power output in the 4-min cycling performance trial was increased in placebo + NaHCO3 (+3.1% ± 1.8%) and β-alanine + NaHCO3 (+3.3% ± 3.0%) compared with baseline (P < 0.05). β-alanine + placebo did not significantly improve average power output compared with baseline (+1.6% ± 1.7%, P = 0.20); however, magnitude-based inferences demonstrated that β-alanine + placebo was associated with a 37% likelihood of producing average power improvements.
In trained cyclists, β-alanine supplementation did not significantly improve 4-min cycling performance; however, there may be a small meaningful improvement in performance. Acute NaHCO3 supplementation significantly improved 4-min cycling performance. There seemed to be a minimal additive effect of combined β-alanine and NaHCO3 supplementation.
本研究旨在探讨 28 天补充 β-丙氨酸对 4 分钟自行车计时赛表现的影响，并确定β-丙氨酸和碳酸氢钠（NaHCO3）联合补充是否对高强度自行车运动表现有累加效应。
14 名高水平自行车运动员（平均 ± 标准差：年龄=25.4 ± 7.2 岁，体重=71.1 ± 7.1 公斤，最大摄氧量（V˙O2max）=66.6 ± 5.7 毫升·公斤·分钟）补充 28 天的 β-丙氨酸（每天 65 毫克·公斤体重）或安慰剂。在补充前（基线）和补充后两次进行最大 4 分钟自行车比赛：在随机交叉设计中，两次试验之间间隔 2 天，分别服用 NaHCO3（300 毫克·公斤体重）和服用安慰剂。在负荷前（补充后试验）和预测试和后测试时测定血 pH 值和 HCO3 浓度。
在急性 NaHCO3 负荷试验中，血 pH 值和 HCO3 值从负荷前升高到预测试，HCO3 值从预测试到后测试的变化幅度明显大于急性安慰剂负荷试验（P < 0.001）。与基线相比，4 分钟自行车运动表现试验中的平均功率输出在安慰剂+NaHCO3（+3.1%±1.8%）和β-丙氨酸+NaHCO3（+3.3%±3.0%）中增加（P < 0.05）。与基线相比，β-丙氨酸+安慰剂对平均功率输出没有显著改善（+1.6%±1.7%，P=0.20）；然而，基于幅度的推断表明，β-丙氨酸+安慰剂与产生平均功率提高的可能性为 37%。
在训练有素的自行车运动员中，β-丙氨酸补充并没有显著提高 4 分钟自行车运动表现；然而，运动表现可能有微小的、有意义的提高。急性 NaHCO3 补充显著提高了 4 分钟自行车运动表现。β-丙氨酸和 NaHCO3 联合补充似乎有最小的累加效应。
