Sugino T, Aoyagi S, Shirai T, Kajimoto Y, Kajimoto O. Effects of Citric Acid and l-Carnitine on Physical Fatigue.
J Clin Biochem Nutr 2011;
41:224-30. [PMID:
18299720 PMCID:
PMC2243251 DOI:
10.3164/jcbn.2007032]
[Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2007] [Accepted: 06/15/2007] [Indexed: 11/29/2022] Open
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.
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