MUSCLE TORQUE IN YOUNG AND OLDER UNTRAINED AND ENDURANCE-TRAINED MEN

Plantar flexor torque was measured in 24 young (25+/-1.4y) and older ( 62+/-2y) untrained and endurance-trained men to test the hypothesis th at age-associated declines in muscle function would be attenuated in o lder men who also endurance trained. Endurance-trained subjects averag ed 7-9 hr/wk of aerobic activity for 10-12 years. These subjects had n ot engaged in resistance training previously in the past 10 years. Pla ntar 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., torq ue . muscle cross-sectional area(-1) and torque . muscle volume(-1)) w ere 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 en durance training does not attenuate the age-associated loss of muscle mass or absolute strength. However, endurance training might reduce th e extent of loss of relative strength because torque . muscle cross-se ctional area(-1) and torque . muscle volume(-1) are greater in enduran ce-trained older men than in untrained older men.