Carnitine has several functions, but is most well known as an essential nutrient required for transporting fatty acids into mitochondria where they are burned as fuel. My colleagues and I have discovered additional functions of carnitine that involve reducing the stress response to resistance exercise. We recently performed a study to validate our prior work and determine if ingesting a smaller dose of of carnitine could also provide an ergogenic effect. Healthy men performed a resistance exercise challenge that included 5 sets of squat exercise on 3 separate occasions. For 3 weeks prior to each test, subjects ingested either 1 g of carnitine L-tartrate (LCLT) per day, 2 g LCLT/day, or a placebo. Similar to our previous work we showed that carnitine supplementation was effective at reducing the acute response of several markers of biochemical stress after resistance exercise including hypoxanthine, xanthine oxidase, and myglobin. In addition, perception of muscle soreness was lower after exercise with carnitine supplementation. A novel finding was that 1 g/day of carnitine was as effective as 2 g/day. The findings indicate that in addition to the traditional role of carnitine as a fat burner, this dietary supplement also helps during recovery from intense exercise.

Spiering BA, Kraemer WJ, Vingren JL, Hatfield DL, Fragala MS, Ho JY, Maresh CM, Anderson JM, Volek JS. Responses of Criterion Variables to Different Supplemental Doses of l-Carnitine l-Tartrate. J Strength Cond Res. 2007 Feb;21(1):259-64.