EFFECT OF L-CARNITINE SUPPLEMENTATION ON MUSCLE AND BLOOD CARNITINE CONTENT AND LACTATE ACCUMULATION DURING HIGH-INTENSITY SPRINT CYCLING

This study examined the effects of 14 days of L-carnitine supplementat ion on muscle and blood carnitine fractions, and muscle and blood lact ate concentrations, during high-intensity sprint cycling exercise. Eig ht subjects performed three experimental trials: control I (CON I, Day 0), control II (CON II, Day 14), and L-carnitine (L-CN, Day 28). Each trial consisted of a 4-min ride at 90% VO2max, followed by a rest per iod of 20 min, and then five repeated 1-min rides at 115% VO2max (2 mi n rest between each). Following CON II, all subjects began dietary sup plementation of L-carnitine for a period of 14 days (4 g/day). Plasma total acid soluble and free carnitine concentrations were significantl y higher (p < .05) at all time points following supplementation. L-car nitine supplementation had no significant effect on muscle carnitine c ontent and thus could not alter lactate accumulation during exercise.