Maximum Tolerated Dose of Walking for Community-Dwelling People Recovering From Hip Fracture: A Dose-Response Trial

Objective To determine how much moderate-intensity physical activity, in the form of walking, could be prescribed for people living in the community after hip fracture in terms of safety, tolerability, and feasibility. Design Phase I dose-response design. Setting Public community rehabilitation centers. Participants Community-dwelling adults (N=21; 16 women; mean age, 75±9y) who were cognitively alert, attending community rehabilitation after hip fracture (mean days postfracture, 110±47d), able to walk with or without a gait aid, and for whom it was safe to participate in physical activity. Interventions Individually supervised doses of moderate-intensity walking completed in 1 week in addition to their usual levels of physical activity. Three participants were required to complete a dose of walking before dose escalation for the next cohort of 3 participants. Dose escalation ceased when >1 participant in a cohort had an adverse event or was unable to tolerate the dose or if the maximum dose of 150min/wk was achieved. Main Outcome Measures Maximum tolerated dose of walking per week (in minutes), adverse events, mobility, and walking confidence. Results The maximum tolerated dose of walking for adults after hip fracture before significant discomfort was experienced (eg, breathlessness, pain, and fatigue) by any participant was 100min/wk. No adverse events occurred, but participants began to be unable to tolerate higher doses beyond 100min/wk. Conclusions This provides preliminary evidence that community-dwelling older adults recovering from hip fracture can complete a sufficient amount of moderate-intensity physical activity to maintain and improve their health.