Citrulline/malate promotes aerobic energy production in human exercising muscle

• Published in: British journal of sports medicine Vol. 36; no. 4; pp. 282 - 289
• Main Authors: Bendahan, D, Mattei, J P, Ghattas, B, Confort-Gouny, S, Le Guern, M E, Cozzone, P J
• Format: Journal Article
• Language: English
• Published: England BMJ Publishing Group Ltd and British Association of Sport and Exercise Medicine 01.08.2002; BMJ Publishing Group Ltd; BMJ Publishing Group LTD; BMJ Publishing Group; BMJ Group
• Subjects: 31P magnetic resonance spectroscopy; Adenosine triphosphatase; Adult; Analysis of Variance; anaplerosis; Applications; Bioenergetics; Citrulline; Citrulline - analogs & derivatives; Citrulline - pharmacology; citrulline/malate; Drug therapy; energetics; energy cost; Energy metabolism; Exercise; Family medical history; Fatigue; Fourier Analysis; Human health and pathology; Humans; Life Sciences; Linear Models; Magnetic Resonance Spectroscopy; Malates - pharmacology; Male; Metabolism; MRS; Muscle Fatigue - drug effects; Muscle, Skeletal - metabolism; Muscles; Muscular system; Original; PCr; phosphocreatine; Physical fitness; Physiological aspects; skeletal muscle; Spectrum analysis; Sports medicine; Statistics; TCA; tricarboxylic acid cycle; France
• ISSN: 0306-3674; 1473-0480
• DOI: 10.1136/bjsm.36.4.282

Background: Previous studies have shown an antiasthenic effect of citrulline/malate (CM) but the mechanism of action at the muscular level remains unknown. Objective: To investigate the effects of CM supplementation on muscle energetics. Methods: Eighteen men complaining of fatigue but with no documented disease were included in the study. A rest-exercise (finger flexions)-recovery protocol was performed twice before (D−7 and D0), three times during (D3, D8, D15), and once after (D22) 15 days of oral supplementation with 6 g/day CM. Metabolism of the flexor digitorum superficialis was analysed by 31P magnetic resonance spectroscopy at 4.7 T. Results: Metabolic variables measured twice before CM ingestion showed no differences, indicating good reproducibility of measurements and no learning effect from repeating the exercise protocol. CM ingestion resulted in a significant reduction in the sensation of fatigue, a 34% increase in the rate of oxidative ATP production during exercise, and a 20% increase in the rate of phosphocreatine recovery after exercise, indicating a larger contribution of oxidative ATP synthesis to energy production. Considering subjects individually and variables characterising aerobic function, extrema were measured after either eight or 15 days of treatment, indicating chronological heterogeneity of treatment induced changes. One way analysis of variance confirmed improved aerobic function, which may be the result of an enhanced malate supply activating ATP production from the tricarboxylic acid cycle through anaplerotic reactions. Conclusion: The changes in muscle metabolism produced by CM treatment indicate that CM may promote aerobic energy production.