UC Davis

Applying magnetic resonance methods to measure the metabolic response in exercise poses a technical challenge because the construction of the ergometer must use non-magnetic components and assess work in the confined space of a magnet bore. The present report details the fabrication of a non-magnetic ergometer for use in a standard Siemens 3 Tesla (T) spectrometer. Using the ergometer, researchers can measure the ³¹P magnetic resonance spectroscopy (MRS) signals during leg muscle exercise and exercise recovery. In particular, the phosphocreatine (PCr) kinetics during exercise recovery reflects the mitochondrial oxidative capacity, and the inorganic phosphate (P_i) signal tracks the cellular pH. The ergometer allows for the use of a personalized, and variable load that normalizes the work for all study participants regardless of their leg strength. The ergometer then enables a standardized MRS comparison of leg muscle bioenergetics.