Muscle Energetics Changes Throughout Maturation: a Quantitative 31P-MRS Analysis

Anne Tonson¹, Sbatsien Ratel², Yann Lefur¹, Patrick Cozzone¹, David Bendahan¹

In this study we investigated whether development quantitatively affected muscle energy production and proton handling during a standardized exercise in prepubescent boys and men using 31-Phosphorus Magnetic Resonance Spectroscopy. We mainly found that maturation significantly affects muscle energetics. We showed that although the total energy cost of contraction was unaffected throughout the maturation process, the relative contribution of each metabolic pathway to ATP production during a standardized exercise changed with respect to age. Children rely more on oxidative metabolism and less on creatine kinase reaction to meet energy demand during exercise whereas anaerobic glycolysis activity was unaffected by development.