title: L-Carnitine L-tartrate supplementation favorably affects markers of recovery from exercise stress.
abstract: We examined the influence of L-carnitine L-tartrate (LCLT) on markers of purine catabolism, free radical formation, and muscle tissue disruption after squat exercise. With the use of a balanced, crossover design (1 wk washout), 10 resistance-trained men consumed a placebo or LCLT supplement (2 g L-carnitine/day) for 3 wk before obtaining blood samples on six consecutive days (D1 to D6). Blood was also sampled before and after a squat protocol (5 sets, 15-20 repetitions) on D2. Muscle tissue disruption at the midthigh was assessed using magnetic resonance imaging (MRI) before exercise and on D3 and D6. Exercise-induced increases in plasma markers of purine catabolism (hypoxanthine, xanthine oxidase, and serum uric acid) and circulating cytosolic proteins (myoglobin, fatty acid-binding protein, and creatine kinase) were significantly (P < or = 0.05) attenuated by LCLT. Exercise-induced increases in plasma malondialdehyde returned to resting values sooner during LCLT compared with placebo. The amount of muscle disruption from MRI scans during LCLT was 41-45% of the placebo area. These data indicate that LCLT supplementation is effective in assisting recovery from high-repetition squat exercise.
authors.affiliation: Human Performance Laboratory, Department of Kinesiology, University of Connecticut, Storrs, Connecticut 06269, USA. jvolek@uconnvm.uconn.edu
authors.forename: Jeff S
authors.initials: JS
authors.lastname: Volek
authors.forename: William J
authors.initials: WJ
authors.lastname: Kraemer
authors.forename: Martyn R
authors.initials: MR
authors.lastname: Rubin
authors.forename: Ana L
authors.initials: AL
authors.lastname: Gómez
authors.forename: Nicholas A
authors.initials: NA
authors.lastname: Ratamess
authors.forename: Paula
authors.initials: P
authors.lastname: Gaynor
mesh_terms: D000328:Adult; D015415:Biomarkers; D002331:Carnitine / Q000097:blood; D018592:Cross-Over Studies; D003600:Cytosol / Q000378:metabolism; D004311:Double-Blind Method; D015444:Exercise / Q000502:physiology*; D005609:Free Radicals / Q000378:metabolism; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008279:Magnetic Resonance Imaging; D008297:Male; D018482:Muscle, Skeletal / Q000473:pathology / Q000503:physiopathology; D010146:Pain / Q000503:physiopathology; D011506:Proteins / Q000378:metabolism; D011687:Purines / Q000378:metabolism; D013312:Stress, Physiological / Q000209:etiology* / Q000378:metabolism* / Q000503:physiopathology; D013644:Tartrates / Q000494:pharmacology*
chemical_list: D015415:Biomarkers; D005609:Free Radicals; D011506:Proteins; D011687:Purines; D013644:Tartrates; D019344:Lactic Acid; D002331:Carnitine