Carnitine is an essential compound that assists in the transport of long chain fatty acids into the mitochondrial matrix for subsequent oxidation. Several lines of evidence however point to additional benefits of carnitine on recovery from exercise. Ischemia results in release of carnitine, increased oxidative stress, and compromised blood flow regulation, which can be overcome by intravascular carnitine administration. Administration of carnitine in an animal model resulted in increased blood flow and force production. The effects of carnitine have been shown to involve multiple mechanisms including antioxidant effects that decrease production of superoxide anions, increased generation of nitric oxide and increased prostacyclin. In healthy men, we reported that carnitine supplementation (2 g/day for 3 wks) resulted in significantly less accumulation of markers of purine degradation, free radical formation, tissue damage, and muscle soreness during and after moderate intensity squat exercise. We recently performed a study to validate our prior work and determine if ingesting a smaller dose 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 additional to the traditional role of carnitine as a fat burner, this dietary supplement also helps during recovery from intense exercise. Collectively, these studies point to a role of carnitine in mitigating the biochemical stress response to 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.