The purpose of this study was to clarify effects of low-intensity resistance training with different movement velocities to failure on maximal strength in elderly adults. Both legs of twelve elderly volunteers (age: 64.8±7.6) were assigned to low-intensity (50% of one repetition maximum: 1RM) unilateral knee extensions with either normal movement conditions (1 s for lifting and lowering, 1 s for relaxing; N) or slow movement conditions (3 s for lifting and lowering, 1 s isometric; S). Both conditions were performed in random order on the same day and knee extensions were performed to failure in each set for three sets. Training was conducted twice per week for a total of 9 weeks. As an index of the training volume, total number of repetitions (NR), total work load (NR*weight; WL) and total contraction time (NR*contraction time per 1 repetition; CT) throughout training period were calculated. To evaluate the effect of maximal strength, we made pre and post training measures of 1 repetition maximum (1RM) and maximal voluntary contraction of knee extension (MVC). Following 9 weeks of training, NR and WL were significantly greater in N than S (P<0.01). CT was significantly longer in S than N (P<0.01). In both conditions, 1RM significantly increased after training period (P<0.01) and there was no significant intergroup difference (P=0.799). There was no significant intergroup difference in percent increases of 1RM (P=0.530, N: 8.9±8.6%, S: 11.5±10.7%). In both conditions, MVC significantly increased after training period (P<0.01) without any significant intergroup difference (P=0.908). On the other hand, there were no significant differences in percent increases of MVC between intergroup (P=0.697, N: 14.3±12.5%, S: 12.7±6.5%). These results suggest that effect of low-intensity resistance training to failure on maximal strength in elderly adults is independent from movement velocities.
