Relationship between changes in muscle strength and muscle volume and intramuscular fat density in healthy subjects —Investigation using MRI—

Abstract

 We examined the percent changes in the muscle strength, muscle volume, and intramuscular fat density in subjects who underwent muscle-strengthening exercises. The subjects continued muscle-strengthening exercises for the quadriceps for 8 weeks. During this period, changes in the muscle strength were measured over time, with magnetic resonance imaging (MRI)-based measurements of the muscle volume and intramuscular fat density. A significant correlation was observed between the percent changes in the muscle strength/muscle volume of the quadriceps and muscle-strengthening exercises. In addition, a significant correlation was also observed between the percent changes in the muscle volume and intramuscular fat density. Muscle-strengthening exercises were found to increase the muscle volume and decrease the intramuscular fat density.