A Methodology Study to Assess Muscle Damage After Eccentric Exercise

An isolated bout of unaccustomed maximal eccentric exercise is associated with muscle force loss for 2-4 days, mild reversible muscle tenderness, and ultra-structural damage to the muscle fibers, elevation of muscle proteins in serum, and a detriment in range of motion. This single center, pilot study is designed to optimize conditions for the robust measurement of functional deficits after muscle damage and to identify markers of repair over 22 days to inform future intervention studies. The primary measure will be limb force (assessed electronically from the ergometer), previous studies have demonstrated that functional measures return fairly rapidly, usually between 2-4 days. Additionally, several biomarkers of muscle function will be measured over 22 days, as well as changes in protein synthesis in biopsy samples Deuterium-labelled water (D2O) will be consumed by all study participants from Day-3 through Day 22 to aid in quantifying newly synthesized proteins.