Effect of Glycine propionyl-L-carnitine on Aerobic and Anaerobic Exercise Performance

Int J Sport Nutr Exerc Metab. 2008 Feb;18(1):19-36. doi: 10.1123/ijsnem.18.1.19.

Abstract

The purpose of this study was to evaluate the effect of glycine propionyl-L-carnitine (GPLC) supplementation and endurance training for 8 wk on aerobic- and anaerobic-exercise performance in healthy men and women (age 18-44 yr). Participants were randomly assigned to 1 of 3 groups: placebo (n=9), 1 g/d GPLC (n=11), or 3 g/d GPLC (n=12), in a double-blind fashion. Muscle carnitine (vastus lateralis), VO(2peak), exercise time to fatigue, anaerobic threshold, anaerobic power, and total work were measured at baseline and after an 8-wk aerobic-training program. There were no statistical differences (p> .05) between or within the 3 groups for any performance-related variable or muscle carnitine concentrations after 8 wk of supplementation and training. These results suggest that up to 3 g/d GPLC for 8 wk in conjunction with aerobic-exercise training is ineffective for increasing muscle carnitine content and has no significant effects on aerobic- or anaerobic-exercise performance.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Carnitine / analogs & derivatives*
  • Carnitine / pharmacology
  • Dietary Supplements
  • Double-Blind Method
  • Exercise / physiology*
  • Female
  • Glycine / pharmacology*
  • Humans
  • Male
  • Muscle, Skeletal / drug effects*
  • Muscle, Skeletal / metabolism
  • Oxygen Consumption*
  • Physical Endurance / physiology

Substances

  • propionylcarnitine
  • Carnitine
  • Glycine