Introduction : 

Carnosine is thought to contribute to homeostasis during muscle contractions as a pH buffer. The chronic ingestion of beta-alanine, the rate-limiting precursor of the dipeptide carnosine (b-alanyl-L-histidine) has been shown to elevate skeletal muscle carnosine content. The present study aimed to investigate whether oral supplementation of beta-alanine could reduce acidosis during high-intensity cycling and thereby affect ventilation and oxygen uptake.

Methods: 

14 male physical education students participated in this placebo-controlled, double-blind study. Subjects were supplemented orally for 4 weeks with 4.8g/day placebo (maltodextrine) or beta-alanine. Before and after supplementation subjects performed a 6-min cycling exercise at an intensity of 50% between ventilatory threshold and maximal oxygen uptake. Capillary blood samples were taken for blood gas analysis and oxygen uptake kinetics were calculated with a bi-exponential model on the breath-by-breath data of three repetitions.

Results: 

Acidosis at 6 min of high intensity cycling was significantly reduced by beta-alanine but not placebo supplementation (p=0.03). There were no differences in capillary lactate and bicarbonate concentrations nor in ventilation and oxygen uptake kinetics between both groups.

Conclusion: 

Beta-alanine supplementation reduces acidosis during high-intensity cycling, without sparing bicarbonate. The reduction in acidosis has however no effect on the fast or slow component of oxygen uptake kinetics.