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Abstract
The ability of an older adult to perform daily tasks is influenced by age-associated reductions in the neuromuscular system. Muscle strength, leg extensor power (LEP), and anaerobic power (AP) are highly related to functional task performance. Strength training has improved this performance in older adults, however, the effects of power training have rarely been studied. The neural adaptations associated with power training may make it a more effective modality than strength training for improving physical function, LEP, and AP. The purpose of this study was to determine the effect of strength and power training on physical function, LEP, and AP in older adults. Thirty-nine men and women (mean age SD = 72.5 6.3 years) with below average LEP were randomly assigned to control (C, n = 15), strength- (ST, n = 13) and power- (PT, n = 11) training groups. The intervention groups met 3 d/wk for 16 weeks while the control group maintained usual activity and attended three lectures during the 16 weeks. Primary outcome measures included: the Continuous Scale Physical Functional Performance (CSPFP) test, 1RM strength, LEP, and AP. Secondary outcome measures included individual functional tasks: walking speed, floor-sit time, and stair-power. Using the pretest as the covariate, a one-way ANCOVA was used to examine differences between the groups on the post-test measures. An effect size (ES) was calculated to examine the standardized magnitude of difference between the groups. Following the intervention, the PT group showed significant improvement compared to the ST (ES = 0.88) and C groups (ES = 0.98) for the CS-PFP total score. The ST group was significantly stronger than the C group (ES =1.63) and exhibited greater average AP (Wkg-1). Stair-power was significantly greater (p = 0.03) in the PT group than the C group, however, no significant differences were observed between groups for peak AP, LEP, walking speed, or floor-sit time (p>0.05). Neither exercise program was superior to the other for improving LEP, AP, or individual functional task performance. Power training was more effective than strength training for improving physical function, as measured by the CS-PFP test, in community-dwelling older adults.