STORRS, Conn.—Supplemental L-carnitine tartrate (as Carnipure™, from Lonza) can support muscle recovery after exercise in middle-aged adults, according to a new trial (Metab Clin Exp. Aug 2010;59(8):1190-99. DOI: 10.1016/j.metabol.2009.11.012). Previous research has shown the beneficial effects of L-carnitine, an amino acid that plays a critical role in fat and energy metabolism, in recovery from exercise in younger subjects.
In the current trial, researchers from the University of Connecticut recruited 18 normally active and healthy middle-aged men and women for the double blind, placebo-controlled study. Subjects received 2 g/d of L-carnitine or placebo for three weeks and three days; following a one-week washout period, they were crossed over to the other treatment. After each intervention period, the subjects performed an acute exercise challenge of four sets of 15 reps of squat/leg press at 50-percent one-rep max. Blood samples were taken before exercise and at 0, 15, 30 and 120 minutes post-exercise and during the subsequent four days.
When subjects had been taking L-carnitine, they had significantly lower levels of purine metabolism, free radical formation, muscle tissue disruption and muscle soreness after the exercise. However, strength and power markers of physical performance were not affected by supplemental L-carnitine.
The researchers concluded L-carnitine supplementation could reduce chemical damage to tissues after exercise and assist in muscle tissue repair in middle-aged adults, a growing segment of the U.S. population. William Kraemer, lead author of the study, added, “Carnipure can play an important role in the diet of middle-aged women and men and positively affect their physical well-being.”