Effect of L-carnitine supplementation on muscle and blood carnitine content and lactate accumulation during high-intensity sprint cycling

Int J Sport Nutr. 1994 Sep;4(3):280-8. doi: 10.1123/ijsn.4.3.280.


This study examined the effects of 14 days of L-carnitine supplementation on muscle and blood carnitine fractions, and muscle and blood lactate concentrations, during high-intensity sprint cycling exercise. Eight subjects performed three experimental trials: control I (CON I, Day 0), control II (CON II, Day 14), and L-carnitine (L-CN, Day 28). Each trial consisted of a 4-min ride at 90% VO2max, followed by a rest period of 20 min, and then five repeated 1-min rides at 115% VO2max (2 min rest between each). Following CON II, all subjects began dietary supplementation of L-carnitine for a period of 14 days (4 g/day). Plasma total acid soluble and free carnitine concentrations were significantly higher (p < .05) at all time points following supplementation. L-carnitine supplementation had no significant effect on muscle carnitine content and thus could not alter lactate accumulation during exercise.

Publication types

  • Clinical Trial
  • Controlled Clinical Trial

MeSH terms

  • Acid-Base Equilibrium / drug effects
  • Adult
  • Alkalosis / blood
  • Alkalosis / physiopathology
  • Bicycling / physiology*
  • Carnitine / administration & dosage
  • Carnitine / analysis*
  • Carnitine / blood
  • Carnitine / pharmacology*
  • Exercise Test
  • Humans
  • Hydrogen-Ion Concentration
  • Lactates / analysis*
  • Lactates / blood*
  • Male
  • Muscle, Skeletal / chemistry*
  • Muscle, Skeletal / drug effects*
  • Oxygen Consumption / physiology
  • Rest / physiology
  • Time Factors


  • Lactates
  • Carnitine