Bellinger Phillip M, Minahan Clare L
a School of Allied Health Sciences , Griffith University , Gold Coast , QLD , Australia.
Eur J Sport Sci. 2016;16(1):88-95. doi: 10.1080/17461391.2015.1005696. Epub 2015 Jan 30.
β-alanine is a common ingredient in supplements consumed by athletes. Indeed, athletes may believe that the β-alanine induced paresthesia, experienced shortly after ingestion, is associated with its ergogenic effect despite no scientific mechanism supporting this notion. The present study examined changes in cycling performance under conditions of β-alanine induced paresthesia. Eight competitive cyclists (VO2max = 61.8 ± 4.2 mL·kg·min(-1)) performed three practices, one baseline and four experimental trials. The experimental trials comprised a 1-km cycling time trial under four conditions with varying information (i.e., athlete informed β-alanine or placebo) and supplement content (athlete received β-alanine or placebo) delivered to the cyclist: informed β-alanine/received β-alanine, informed placebo/received β-alanine, informed β-alanine/received placebo and informed placebo/received placebo. Questionnaires were undertaken exploring the cyclists' experience of the effects of the experimental conditions. A possibly likely increase in mean power was associated with conditions in which β-alanine was administered (±95% CL: 2.2% ± 4.0%), but these results were inconclusive for performance enhancement (p = 0.32, effect size = 0.18, smallest worthwhile change = 56% beneficial). A possibly harmful effect was observed when cyclists were correctly informed that they had ingested a placebo (-1.0% ± 1.9%). Questionnaire data suggested that β-alanine ingestion resulted in evident sensory side effects and six cyclists reported placebo effects. Acute ingestion of β-alanine is not associated with improved 1-km TT performance in competitive cyclists. These findings are in contrast to the athlete's "belief" as cyclists reported improved energy and the ability to sustain a higher power output under conditions of β-alanine induced paresthesia.
β-丙氨酸是运动员所服用补充剂中的常见成分。实际上，运动员可能认为，摄入后不久出现的由β-丙氨酸引起的感觉异常与它的促力效果有关，尽管并无科学机制支持这一观点。本研究考察了在β-丙氨酸引起感觉异常的情况下自行车骑行表现的变化。八名竞技自行车运动员（最大摄氧量=61.8±4.2毫升·千克·分钟⁻¹）进行了三次练习，一次基线测试和四次实验性试验。实验性试验包括在四种条件下进行的1公里自行车计时赛，向自行车运动员提供不同的信息（即运动员被告知服用β-丙氨酸或安慰剂）和补充剂内容（运动员服用β-丙氨酸或安慰剂）：被告知服用β-丙氨酸/服用β-丙氨酸、被告知服用安慰剂/服用β-丙氨酸、被告知服用β-丙氨酸/服用安慰剂以及被告知服用安慰剂/服用安慰剂。通过问卷调查来探究自行车运动员对实验条件效果的体验。平均功率可能的增加与服用β-丙氨酸的条件有关（±95%可信区间：2.2%±4.0%），但这些结果对于表现提升并无定论（p=0.32，效应量=0.18，最小有价值变化=56%有益）。当自行车运动员被正确告知他们服用的是安慰剂时，观察到了可能有害的影响（-1.0%±1.9%）。问卷调查数据表明，摄入β-丙氨酸会导致明显的感觉副作用，六名自行车运动员报告有安慰剂效应。在竞技自行车运动员中，急性摄入β-丙氨酸与1公里计时赛表现的改善无关。这些发现与运动员的“信念”相反，因为自行车运动员报告在β-丙氨酸引起感觉异常的情况下精力有所改善，且维持更高功率输出的能力增强。
