Muscle Torque in Young and Older Untrained and Endurance-trained Men

Plantar flexor torque was measured in 24 young (25 +/- 1.4 y) and older (62 +/- 2 y) untrained and endurance-trained men to test the hypothesis that age-associated declines in muscle function would be attenuated in older men who also endurance trained. Endurance-trained subjects averaged 7-9 h/wk of aerobic activity for 10-12 years. These subjects had not engaged in resistance training previously in the past 10 years. Plantar flexor torque was measured at velocities between 0 and 5.23 rads. s-1. In absolute terms, maximal isometric torque was 23% lower in older men compared to young men, regardless of their training status. On the other hand, relative measures of isometric strength (i.e., torque.muscle cross-sectional area-1 and torque.muscle volume-1) were similar in young and older men but were higher in trained than in untrained men. Isokinetic torque.muscle cross-sectional area-1 and torque.muscle volume-1 was greater at contraction velocities of 0.26-2.09 rads.s-1 for trained subjects. These data suggest that endurance training does not attenuate the age-associated loss of muscle mass or absolute strength. However, endurance training might reduce the extent of loss of relative strength because torque-muscle cross-sectional area-1 and torque.muscle volume-1 are greater in endurance-trained older men than in untrained older men.