Changes in knee extension peak torque and body composition and their relationship with change in gait speed.

While change in strength affects change in gait speed in both sexes, the effects of body composition change differ by sex. Dual-energy X-ray absorptiometry-based estimates of lean mass may be confounded by intramuscular fat. Future studies should examine sex-specific combined effects of change in strength and body composition on mobility using multiple techniques to measure body composition. Intervention studies should consider testing sex-specific interventions on body composition.