L -Carnitine and the recovery from exhaustive endurance exercise: a randomised, double-blind, placebo-controlled trial.
We hypothesised that L: -carnitine could accelerate recovery from exhaustive exercise since increased blood L: -carnitine concentrations elicit a vasodilation in isolated animal vessels as well as in patients with peripheral vascular or coronary artery disease during exercise. Twelve subjects received either 2 g L: -carnitine or a placebo in a study which was double-blind and crossover in design. Two hours after administration, the subjects performed a constant-load exercise test (CET(1)) cycling at their individual anaerobic threshold to exhaustion. Three hours later this test was repeated (CET(2)). After 4-14 days, each subject performed the same cycling tests after having taken the other substance. Exercise times of the 12 subjects were identical with L: -carnitine (CET(1): 21.3+/-5.7 min; CET(2): 21.4+/-5.3 min) and placebo (CET(1): 21.9+/-6.2 min; CET(2): 20.4+/-4.8 min). Also, heart rate, oxygen consumption, respiratory exchange ratio, and blood lactate concentration were identical. In conclusion, 2 g of L-carnitine taken 2 h before a first of two constant-load exercise tests had no influence on the second tests performed 3 h after the first test compared with placebo.
Stuessi
Christoph
C
Exercise Physiology, Institute of Human Movement Sciences, Swiss Federal Institute of Technology of Zurich, Zurich, Switzerland.
Hofer
Pierre
P
Meier
Christian
C
Boutellier
Urs
U
D000328:Adult; D015308:Anaerobic Threshold; D002331:Carnitine / Q000097:blood / Q000494:pharmacology*; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D006339:Heart Rate; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D010807:Physical Endurance / Q000502:physiology*; D012123:Pulmonary Ventilation; D014664:Vasodilation / Q000187:drug effects*
D019344:Lactic Acid; D002331:Carnitine