Velocity training induces power-specific adaptations in highly functioning older adults

Objective: To test the efficacy of high-velocity training in healthy older persons. Design: A 12-week randomized trial, with subjects blocked for gender and residence, comparing high-velocity resistance training with a self-paced walking program. Setting: Retirement community. Participants: Forty-three volunteers over the age of 70 years. Intervention: Power group: high-velocity leg exercises 3 times weekly with weekly increases in resistance combined with 45 minutes of moderate, nonresistance exercise weekly. Walking group: moderate intensity exercise 30 minutes daily, 6 days weekly. Main Outcome Measures: Variables measured included leg press peak power and leg extensor strength. Functional performance outcomes included: 6;minute walk distance, Short Physical Performance Battery, Physical Performance Test, and Medical Outcomes Study Short-Form Health Survey. Results: Peak power improved 22% (p =.004) in the power group (3.7 +/- 1.0W/kg to 4.5 +/- 1.4W/kg) but did not change in the walking group (3.99 +/- .76W/kg to 3.65 +/- .94W/kg). Leg extensor power at resistance of 50%,:60%, and 70% of body weight increased 50%, 77%, and 141%, respectively, in the power group (p <.0001, repeated-measures analysis of variance). Strength improved 22% in the power-trained individuals and 12% in the walkers (p <.0001). Training did not improve functional task performance in either group. One subject developed a radiculopathy during training. Conclusions: Resistance training focusing on speed of movement improved leg power and maximal strength substantially, but did not improve functional performance in healthy high-functioning older volunteers.