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.
O’Neill, Taylor, Dzialoszynski, and Noble are with the School of Kinesiology at the University of Western Ontario, London, Ontario N6A 3K7 Canada. Taylor is also with the Department of Physiology at the university. Thayer is with the School of Kinesiology al Lakehead University, Thunder Bay, Ontario P7B 5E1 Canada.