The effects of dietary L-carnitine on anaerobic exercise lactate in elite male athletes

The effects of dietary L-carnitine supplementation on lactate (LA(-)) accumulation following anaerobic exercise were examined by assessing blood LA concentration before and after an intense 600-m sprint in 26 elite male runners (age 20.9 +/- 2.4 yrs) who ingested either 2 g per day of L-carnitine or a placebo for 21 days in a double-blind, crossover study. A 7-day washout period occurred at the end of the first treatment. Statistical analyses revealed no significant differences in either preexercise or postexercise blood LA(-) after ingestion of L-carnitine vs. placebo. In addition, subjects who received L-carnitine last did not have significantly different postexercise blood LA(-) levels than those who received carnitine first. Likewise, those ingesting the placebo last did not have significantly different postexercise blood LA(-) values than those receiving it first. Moreover, since exercise times under either treatment did not differ significantly, the apparent inability of carnitine supplementation to affect this indicator of fatigue was likely not due to differences in exertion. Thus it is concluded that supplementation of L-carnitine as provided in this study had no effect on LA(-) accumulation during maximal anaerobic exercise.