Effect of glycine propionyl-L-carnitine on aerobic and anaerobic exercise performance.
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.
Smith
Webb A
WA
Dept. of Health and Sport Sciences, University of Memphis, Memphis, TN 38152, USA.
Fry
Andrew C
AC
Tschume
Lesley C
LC
Bloomer
Richard J
RJ
D000293:Adolescent; D000328:Adult; D002331:Carnitine / Q000031:analogs & derivatives* / Q000494:pharmacology; D019587:Dietary Supplements; D004311:Double-Blind Method; D015444:Exercise / Q000502:physiology*; D005260:Female; D005998:Glycine / Q000494:pharmacology*; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000378:metabolism; D010101:Oxygen Consumption; D010807:Physical Endurance / Q000502:physiology
C003223:propionylcarnitine; D002331:Carnitine; D005998:Glycine