P-31 NMR-SPECTROSCOPY AND ELECTROMYOGRAPHY DURING EXERCISE AND RECOVERY IN PATIENTS WITH FIBROMYALGIA

Objective. To investigate whether patients with fibromyalgia (FM) have normal motor unit recruitment in relation to muscle metabolism during exhausting exercise and recovery, and whether the reduced voluntary m uscle force normally seen is related to a smaller muscle size. Method. Female patients with FM and sedentary controls were examined using si multaneous P-31 nuclear magnetic resonance spectroscopy (NMR) and surf ace electromyography (SEMG) during exhaustive static exercise of the a nterior tibial muscle and during recovery. The maximum voluntary contr action force was estimated, and the maximum cross sectional muscle are a was evaluated using H-1 NMR imaging. The sedentary controls were mat ched to patients for sex, age and, as far as possible, daily physical activity levels. Results. Patients with FM had reduced maximum volunta ry contraction force in relation to the sedentary controls, despite ha ving similar muscle size. In general the myoelectrical-metabolic relat ion during exercise and recovery was normal in patients with FM. Concl usion. The less extreme changes in motor unit recruitment and metaboli sm during exhaustive exercise indicated a lower exercise tolerance tha t could be connected with the lower physical activity levels.