Ergogenic Effects of β-Alanine and Carnosine: Proposed Future Research to Quantify Their Efficacy

beta-alanine is an amino acid that, when combined with histidine, forms the dipeptide carnosine within skeletal muscle. Carnosine and beta-alanine each have multiple purposes within the human body; this review focuses on their roles as ergogenic aids to exercise performance and suggests how to best quantify the former's merits as a buffer. Carnosine normally makes a small contribution to a cell's total buffer capacity; yet beta-alanine supplementation raises intracellular carnosine concentrations that in turn improve a muscle's ability to buffer protons. Numerous studies assessed the impact of oral beta-alanine intake on muscle carnosine levels and exercise performance. beta-alanine may best act as an ergogenic aid when metabolic acidosis is the primary factor for compromised exercise performance. Blood lactate kinetics, whereby the concentration of the metabolite is measured as it enters and leaves the vasculature over time, affords the best opportunity to assess the merits of beta-alanine supplementation's ergogenic effect. Optimal beta-alanine dosages have not been determined for persons of different ages, genders and nutritional/health conditions. Doses as high as 6.4 g day(-1), for ten weeks have been administered to healthy subjects. Paraesthesia is to date the only side effect from oral beta-alanine ingestion. The severity and duration of paraesthesia episodes are dose-dependent. It may be unwise for persons with a history of paraesthesia to ingest beta-alanine. As for any supplement, caution should be exercised with beta-alanine supplementation.