Effects of Short-Term Resistance Training on Muscle Strength and Morphology in the Elderly

Ten moderately active participants (8 women, 2 men; mean age 66.3 ± 1.2 years), engaged in 8 weeks of isotonic knee-extensor resistance training. Afterward, peak torque output (180°/s) and mean power increased 30.8% and 27.2%, respectively, in the experimental limb (EL). A moderate, nonsignificant cross-over training effect was observed in the contralateral untrained limb (CL) for the same measures. Whereas mean fiber cross-sectional area (CSA) was unaltered in the CL by training. Fiber Types I and lib in the EL displayed increased CSA. However, mean CSAs for all fiber types in the trained EL were no larger ( p > .05) than those observed in the CL before or after training. There were no significant changes in muscle-fiber-type composition, the proportion of Type I myosin heavy chain, or Type Ha CSA. These data suggest that short-term resistance training can significantly increase isokinctic peak torque in the elderly, with minimal changes in the histochemical and biochemical parameters examined.