Effects of Exercise Induced Muscle Damage on Critical Torque and Mitochondrial Function

Abstract

The primary aim of this study was to examine the effects of exercise induced muscle damage on critical torque and impulse above end test torque. A secondary purpose was to determine whether mitochondrial function played any role in observed changes. A total of 12 participants performed resting mitochondrial tests, MVC level tests, and a 5-minute all-out isometric knee extension test for critical torque both before and 48-hours following exercise induced muscle damage via electrical stimulation and eccentric isokinetic knee extension. Surface EMG was collected during the critical torque tests to ensure full effort was given. The muscle damage protocol was successful in seven of the participants. Of those seven, one was excluded for mitochondrial function analysis due to being an outlier. The primary findings were that exercise induced muscle damage 1) results in a reduced critical torque, 2) a reduced impulse above end test torque and 3) did not alter mitochondrial function in the working muscle. These findings could indicate that although oxidative capacity plays a large role in determining critical torque, there is more at play due to the lack of change in mitochondrial function. The drop in impulse above end power indicates the importance of muscular work capacity.