ORIGINAL RESEARCH: PDF OnlyRESPONSES OF CRITERION VARIABLES TO DIFFERENT SUPPLEMENTAL DOSES OF L-CARNITINE L-TARTRATESPIERING, BARRY A.; KRAEMER, WILLIAM J.; VINGREN, JAKOB L.; HATFIELD, DISA L.; FRAGALA, MAREN S.; HO, JEN-YU; MARESH, CARL M.; ANDERSON, JEFFREY M.; VOLEK, JEFF S. Author Information Human Performance Laboratory, Department of Kinesiology, University of Connecticut, Storrs, Connecticut 06269. Address correspondence to Dr. William Kraemer, [email protected]. Journal of Strength and Conditioning Research 21(1):p 259-264, February 2007. Free Abstract L-carnitine L-tartrate (LCLT) supplementation beneficially affects markers of postexercise metabolic stress and muscle damage. However, to date, no study has determined the dose response of LCLT to elicit such responses. Therefore, the purpose of this study was to determine the effects of different doses of LCLT on criterion variables previously shown to be responsive to LCLT supplementation. Eight healthy men (22 ± 3y,174 ± 5 cm, 83.0 ± 15.3 kg) were supplemented with 0 g, 1 g, and 2 g of LCLT for 3 weeks and then performed a bout of resistance exercise (5 sets of 15–20 repetition maximum with a 2-min rest between sets) with associated blood draws. This procedure was performed in a balanced, randomized, repeated measures design. Serum carnitine concentrations increased (p ≤ 0.05) following the 1 g and 2 g doses, with the 2-g dose providing the highest carnitine concentrations. The 1- and 2-g doses reduced postexercise serum hypoxanthine, serum xanthine oxidase, serum myoglobin, and perceived muscle soreness. In conclusion, both the 1- and 2-g doses were effective in mediating various markers of metabolic stress and of muscle soreness. Use of LCLT appears to attenuate metabolic stress and the hypoxic chain of events leading to muscle damage after exercise. © 2007 National Strength and Conditioning Association
