Effects of Four Weeks L-carnitine L-tartrate Ingestion on Substrate Utilization During Prolonged Exercise

Int J Sport Nutr Exerc Metab. 2005 Dec;15(6):665-79. doi: 10.1123/ijsnem.15.6.665.

Abstract

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.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Administration, Oral
  • Adult
  • Area Under Curve
  • Bicycling / physiology*
  • Carnitine / administration & dosage*
  • Carnitine / blood
  • Carnitine / urine
  • Cross-Over Studies
  • Dietary Supplements
  • Double-Blind Method
  • Energy Metabolism / drug effects*
  • Energy Metabolism / physiology
  • Humans
  • Male
  • Middle Aged
  • Oxidation-Reduction
  • Oxygen Consumption / drug effects
  • Oxygen Consumption / physiology
  • Physical Endurance / drug effects*
  • Physical Endurance / physiology
  • Tartrates / administration & dosage*
  • Time Factors

Substances

  • Tartrates
  • Carnitine
  • tartaric acid