This study compares the effects of two uniquely different lower extremity power training interventions on alterations in muscle power, physical performance, neuromuscular activation, and muscle cross sectional area in mobility-limited older adults. Fifty-two subjects (78±5 years, short physical performance battery score: 8.1±1) were placed at random into either 16 weeks of progressive high velocity resistance training performed at low external resistance (40% of the 1-repetition maximum [1-RM] [LO]) or high external resistance (70% of 1RM [HI]). Both groups completed three sets of leg and knee extension exercises at maximum voluntary velocity, twice per week. Neuromuscular activation was assessed using surface electromyography and muscle cross sectional area (CSA) was measured using computed tomography. At 16 weeks, LO and HI exhibited significant and similar within-group increases of leg extensor peak power (~34% vs ~42%), strength (~13% vs ~19%), and SPPB score (1.4±0.3 vs 1.8±0.3 units), respectively (all P .25).
The study found high velocity resistance training with low external resistance to yield similar improvements in muscle power and physical performance in comparison to training with high external resistance in mobility-limited elders. These findings may have signifanct implications for optimizing exercise interventions for older adults with mobility limitations.