Effect of L-carnitine supplementation on muscle and blood carnitine content and lactate accumulation during high-intensity sprint cycling.
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.
Barnett
C
C
Human Performance Laboratory, Ball State University, Muncie, IN 47306.
Costill
D L
DL
Vukovich
M D
MD
Cole
K J
KJ
Goodpaster
B H
BH
Trappe
S W
SW
Fink
W J
WJ
D000136:Acid-Base Equilibrium / Q000187:drug effects; D000328:Adult; D000471:Alkalosis / Q000097:blood / Q000503:physiopathology; D001642:Bicycling / Q000502:physiology*; D002331:Carnitine / Q000008:administration & dosage / Q000032:analysis* / Q000097:blood / Q000494:pharmacology*; D005080:Exercise Test; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007773:Lactates / Q000032:analysis* / Q000097:blood*; D008297:Male; D018482:Muscle, Skeletal / Q000737:chemistry* / Q000187:drug effects*; D010101:Oxygen Consumption / Q000502:physiology; D012146:Rest / Q000502:physiology; D013997:Time Factors
D007773:Lactates; D002331:Carnitine