Performance effects of acute β-alanine induced paresthesia in competitive cyclists

beta- alanine is a common ingredient in supplements consumed by athletes. Indeed, athletes may believe that the beta- 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 beta- alanine induced paresthesia. Eight competitive cyclists ( VO2max = 61.8 +/- 4.2 mL center dot kg center dot 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 beta- alanine or placebo) and supplement content ( athlete received beta- alanine or placebo) delivered to the cyclist: informed beta- alanine/ received beta- alanine, informed placebo/ received beta- alanine, informed beta- 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 beta- 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 beta- alanine ingestion resulted in evident sensory side effects and six cyclists reported placebo effects. Acute ingestion of beta- 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 beta- alanine induced paresthesia.