A pilot randomized controlled trial of exercise to improve walking energetics among older adults with mobility limitation: The HealthySteps Study

Mobility is a fundamental component of healthy aging; however, mobility limitation is a prevalent, energetically costly problem among older adults. We conducted a pilot randomized controlled trial to compare the effects of two, 12-week exercise interventions (timing and coordination, TC; aerobic walking, AW) to an active control (stretching and relaxation; SR) on outcomes related to mobility among community-dwelling older adults with mobility limitation (n=72). At 12 weeks, TC reduced mean energy cost of walking by 13-15% versus SR. Among those with high baseline cost, TC reduced mean energy cost by 20-26% versus SR. Reductions were maintained at 24-week follow-up. AW had no effect at 12 or 24 weeks. Fatigability, daily physical activity, endurance, physical function, and life-space mobility did not change with TC or AW versus SR at 12 or 24 weeks. In summary, 12 weeks of TC, but not AW, improved walking economy among older adults with mobility limitation.