title: Effects of Citric Acid and l-Carnitine on Physical Fatigue.
abstract: We examined the effects of citric acid and l-carnitine administration on physical fatigue. In a double-blind, placebo-controlled, 3-way crossover study, 18 healthy volunteers were randomized to oral citric acid (2,700 mg/day), l-carnitine (1,000 mg/day), or placebo for 8 days. The fatigue-inducing physical task consisted of workload trials on a cycle ergometer at fixed workloads for 2 h on 2 occasions. Before the physical load, salivary chromogranin A, measured as a physiological stress marker, was lower in the group given citric acid than in the group given placebo. Also, after the physical load, the subjective feeling of fatigue assessed with a visual analogue scale was lower in the citric acid group than in the placebo group. In contrast, l-carnitine had no effect on chromogranin A or subjective fatigue. These results suggest that citric acid reduces physiological stress and attenuates physical fatigue, whereas l-carnitine does not.
authors.affiliation: Research and Development Division, Soiken Inc. 1-4-2 Shinsenrihigashimachi, Toyonaka, Osaka 560-0082, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Sugino
authors.forename: Sayaka
authors.initials: S
authors.lastname: Aoyagi
authors.forename: Tomoko
authors.initials: T
authors.lastname: Shirai
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Kajimoto
authors.forename: Osami
authors.initials: O
authors.lastname: Kajimoto