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., The data detail the construction and application of a non-magnetic ergometer that enables researchers to use magnetic resonance imaging/spectroscopy (MRI/MRS) methods to measure the metabolic changes in exercising human muscle in vivo as a function of work level relative to the maximum voluntary contraction (MVC).  Using the ergometer and MRI/MRS methods allows researchers to measure the 31P NMR signals from muscle and utilize the pH and phosphocreatine (PCr) to assess muscle bioenergetics during and after exercise.  Specifically, the recovery kinetics of the PCr immediately after the cessation of exercise provides a unique perspective on the   contrasting mitochondrial functions in normal and compromised muscle in patients suffering from different diseases, such as chronic kidney disease and on the efficacy of therapeutic intervention., , # An ergometer to measure muscle bioenergetics with magnetic resonance techniques

[https://doi.org/10.5061/dryad.08kprr59v](https://doi.org/10.5061/dryad.08kprr59v)

## Description of the data and file structure

Fig. 1 shows the ergometer built from non-magnetic material (wood, plastic, aluminum). The ergometer fits into a commonly available 3T Siemens scanner where MRI/MRS methods can then follow the metabolism in exercising muscle.

Figure 2 shows the position of the subject’s leg in the ergometer. The slider, a sliding component, rests on the subject’s ankle. As the subject’s leg kicks, the foot pushes against the slider and raises it toward a stop plate. The slider’s travel distance from rest to the stop plate defines a critical parameter in calculating work. A weight placed on the foot sets the workload.

Figure 3 shows the ergometer positioned in a 3-T scanner. A surface coil resting on top of the leg detects the MRS signal during and after exercise. Slots in the ergometer allow...