Functional Characteristic Properties of Skeletal Muscle Tissue Assessed by P31 Spectroscopy in Young and Older Adults

P31 nuclear magnetic resonance (RMN) Spectroscopy (SRM P31) has currently being poorly used in the field of sarcopenia. The aim of the CAMUS study is to investigate the feasibility a protocol of SRM P31 at rest, during and after a standardized physical task. The secondary objective is to compare the metabolism of tyhe skeletal muscle tissue assessed by SRM P31 in young and older individuals. A pilot study, cross-sectional study will be conducted. Ten healthy sedentary 70+ years males and 10 sedentary 25 to 30 years old male will be included. Level of physical activity, physical performances, will be assessed at baseline. RMN (T1; tractography and SRM P31) will be performed. SRM P31 will be performed at rest, during and after an exhausting muscle task at 70% 1-RM. Feasibility will be judged on the rate of valuable variables recorded (\>90%) inorganic phosphate (iP), phosphocreatine (PCr) and isoform of adenosine triphosphate (ATP : alfa, beta, gamma).