Effects of four weeks L-Carnitine L-tartrate ingestion on substrate utilization during prolonged exercise

• Published in: International journal of sport nutrition and exercise metabolism Vol. 15; no. 6; pp. 665 - 679
• Main Authors: Broad, E.M, Maughan, R.J, Galloway, S.D.R
• Format: Journal Article
• Language: English
• Published: United States 01.12.2005
• Subjects: Administration, Oral; Adult; Area Under Curve; athletes; athletic performance; bicycling; Bicycling - physiology; carbohydrate metabolism; carnitine; Carnitine - administration & dosage; Carnitine - blood; Carnitine - urine; Cross-Over Studies; Dietary Supplements; Double-Blind Method; Energy Metabolism - drug effects; Energy Metabolism - physiology; ergogenic aids; exercise; Humans; lipid metabolism; Male; men; Middle Aged; Oxidation-Reduction; Oxygen Consumption - drug effects; Oxygen Consumption - physiology; Physical Endurance - drug effects; Physical Endurance - physiology; sports nutrition; tartaric acid; Tartrates - administration & dosage; Time Factors
• ISSN: 1526-484X; 1543-2742
• DOI: 10.1123/ijsnem.15.6.665

In a randomized, placebo-controlled, double-blind crossover design, 15 trained males undertook exercise trials during two 4 wk supplementation periods, with either 3 g L-Carnitine L-tartrate (LCLT) or 3 g placebo (P) daily. Total carbohydrate and fat oxidation during 90 min steady state cycling were not different between 0 or 4 wk within LCLT or P trials (mean +/- standard deviation: carbohydrate oxidation P0 99 +/- 36, P4W 111 +/- 27, LCLT0 107 +/- 33, LCLT4W 112 +/- 32 g, respectively; fat oxidation P0 99 +/- 28, P4W 92 +/- 21, LCLT0 94 +/- 18, LCLT4W 90 +/- 22 g, respectively). Subsequent 20 km time trial duration was shorter after P (P0 31:29 +/- 3:50, P4W 29:55 +/- 2:58 min:s, P < 0.01), with no significant change over LCLT (LCLT0 31:46 +/- 4:06, LCLT4W 31.19 +/- 4.08 min:s). Four weeks LCLT supplementation had no effect on substrate utilization or endurance performance.