An ergometer to measure muscle bioenergetics with magnetic resonance techniques

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 NMR 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
(Pi) signal tracks the cellular pH. The ergometer allows for a
personalized, and variable load to be lifted leading to total work
performed across study participants being similar regardless of their leg
strength. The ergometer then enables a standardized magnetic resonance
spectroscopy (MRS) comparison of leg muscle bioenergetics between study
participants.