High-velocity resistance training increases skeletal muscle peak power in older women

OBJECTIVES: Peak power declines more precipitously than strength with advancing age and is a reliable measure of impairment and a strong predictor of functional performance. We tested the hypothesis that a high-velocity resistance-training program (HI) would increase muscle power more than a traditional low-velocity resistance-training program (LO). DESIGN: Randomized controlled trial. SETTING: University-based human physiology laboratory. PARTICIPANTS: Thirty women with self-reported disability (aged 73 1, body mass index 30.1 +/- 1.1 kg/ml(2)). INTERVENTION: We conducted a randomized trial comparing changes in skeletal muscle power and strength after 16 weeks of HI or LO. Training was performed three times per week, and subjects completed three sets (8-10 repetitions) of leg press (LP) and knee extension (KE) exercises at 70% of the one-repetition maximum (1RM). MEASUREMENTS: One-repetition maximum (1RM) and peak power for KE and LP. RESULTS: IT and KE relative training force and total work were similar between groups (P > .05). However, HI generated significantly higher power during training sessions than LO for LP (3.7-fold greater, P < .001) and KE (2.1-fold greater, P < .001). Although LP and KE 1RM muscle strength increased similarly in both groups as a result of the training (P < .001), LP peak power increased significantly more in HI than in LO (267 W vs 139 W, P <.001). Furthermore, HI resulted in a significantly greater improvement in LP power at 40%, 50%, 60%, 70%, 80%, and 90% of the 1RM than did LO (P < .05). CONCLUSIONS: HI improved 1RM strength similarly and was more effective in improving peak power than was traditional LO in older women. Improvements in lower extremity peak power may exert a greater influence on age-associated reductions in physical functioning than other exercise interventions.