Abstract

To compare the effects of mechanical work versus fatique on the improvement of work capacity of muscle, young, healthy men were selected to lift a 45-pound weight with their quadriceps for 30 sessions, followed by 5 sessions of testing. The study consisted of two phases. Subjects in the first phase did equal amounts of mechanical work with both quadriceps, but had different amounts of fatique from side to side because the rate of work was different. Subjects in the second phase fatiqued both quadriceps, but one quadriceps was fatiqued with a rest period between contraction cycles, and one was fatiqued without a rest period, thus allowing the side with the rest cycle to do more mechanical work. To test the relative effects of training, a transfer-of-training design was used in both phases. The results suggest that fatique, defined operationally as the inability or unwillingness of the subject to continue the prescribed taskunder given reinforcement conditions, plays a larger role in the development of work capacity of muscle than the amount of mechanical work per se. Verf.-Referat