EFFECTS OF WEIGHT TRAINING ON ISOKINETIC KNEE FLEXION PEAK TORQUE IN ELDERLY WOMEN

Abstract

929 Improving knee flexor (KF) peak torque (PT) in older adults could reduce the risks and consequences of falling because, in previous studies, elderly people with a history of falling have demonstrated lower KF PT than non-fallers. The purpose of this study was to determine if KF PT increased in elderly women after 4 and 8 wk of weight training. Women (age 68.4±0.7 y; mean±SD) were randomly placed into a weight training group (n=8) or control group (n=7). Training was progressive (starting at 80% initial 1-RM) and performed (3 d·wk-1, 3 sets) on machines equipped with weight-plates. Exercises were performed bilaterally and consisted of knee extension, knee flexion, and leg press. The 1-RM increased (p<0.05) in all exercise. Bilateral KF 1-RM increased 99±12% (±SE) and 156±21% after 4 and 8 wk, respectively. Right-limb KF PT was measured at 30 °, 60 °, 180 °, and 240 °·s-1 on a Cybex II™ isokinetic dynamometer. Relative PT (Nm·kg body mass-1) increased (p<0.05) from baseline at 4 and 8 wk for each velocity. Increases were 24±8% and 35±10% at 30°·sec-1, 17±2% and 27±2% at 60°·sec-1, 39±6% and 58±10% at 180°·sec-1, and 42±7% and 60±9% at 240°·sec-1 at 4 and 8 wk, respectively. Only at 240·s-1 were increases not significant between 4 and 8 wk. Controls did not show any significant changes in PT. These data show that, with only 4 wk of strength training, elderly women can improve KF 1-RM strength as well as KF PT over a wide range of contraction velocities. These strength improvements, especially at faster velocities, may enable older adults to respond more successfully to a balance perturbation.