Abstract #1684

Nicolay K, De Feyter H, van den Broek N, de Graaf L, Prompers J

31P magnetic resonance spectroscopy can be used to measure oxidative capacity of skeletal muscle by determining the rate of phosphocreatine (PCr) recovery after exercise. However, cytosolic pH has a strong influence on the kinetics of PCr recovery and therefore at a low end-exercise pH PCr recovery might not be a good measure of oxidative capacity. We investigated the intersubject differences in the effect of acidosis on PCr recovery kinetics in healthy subjects. The pH dependence of the rate of PCr recovery differed among subjects and therefore no general formula can be applied to correct for differences in end-exercise pH.