263-268It is generally assumed that men display greater strength and muscle capacity than women. However, previous
biochemical and histological studies have shown that men have greater capacity for anaerobic metabolism and women have
higher or similar oxidative metabolism. Therefore, in the present study, we estimated oxidative capacity of gastrocnemius
muscle and compared in Indian men and women using non-invasive in vivo ³¹P magnetic resonance spectroscopy (MRS).
Healthy subjects (8 young males and 9 females, age-matched) performed plantar flexion exercise within a magnet and MRS
measurements of inorganic phosphate (Pi), phosphocreatine (PCr), ADP, and pH of the calf muscles were carried out using a
1.5 T whole-body MRI system. PCr values during recovery were fitted to an exponential curve, and oxidative capacity was
calculated using rate constant (kPCr), as an index of oxidative phosphorylation. When men and women were compared for
different metabolic ratios, ADP, pH, kPCr and oxidative capacity, all parameters turned out to be statistically insignificant.
The results showed no gender effect on skeletal muscle oxidative metabolism. The study demonstrated the usefulness of
such non-invasive method to indirectly measure the oxidative capacity of the muscle based on PCr recover