Developing an intensive aerobic exercise program after stroke: A pilot study

Stroke is a major cause of disability. Exercise is associated with reduced stroke recurrence and improved function. Most interventions have focused on supervised training in clinical settings rather than unsupervised home exercise.

To determine the feasibility of conducting a randomized trial comparing unsupervised, high-intensity home aerobic training to a waitlist control group in survivors of stroke.

Assessor blinded randomized controlled pilot study.

Assessments in medical center, home training.

Twenty-three participants who sustained a mild-moderate stroke (National Institutes of Health Stroke Scale score <15) at least 3 months prior were randomized to home aerobic training or waitlist control.

Aerobic training consisted of 8 weeks of stationary bicycle training, five times per week for 30 minutes with heart rate-guided intensity. Control group maintained their normal activities.

Adherence and retention were the primary focus of this evaluation. Secondary outcomes (aerobic capacity VO₂max, gait, balance, and functional tests) were included for initial efficacy.

Of the 23 participants, only 15 were retained in the study. Dropouts were predominantly in the waitlist control group (3/13 in aerobic group, 5/10 in control group). No serious adverse events occurred. Self-efficacy and adherence to training duration and frequency was high, but only 50% achieved exercise intensity goals. Training benefits were modest with a VO₂max increase of 1.7 mL/kg/min in the intervention group. The only statistical improvement in outcomes was with box and block testing, likely due to baseline intergroup differences.

Before conducting a larger trial, challenges with home aerobic training in the stroke population must be addressed. Despite high exercise self-efficacy, there was high attrition, particularly in the waitlist control group. Future study design should implement an active control. Benefits were limited, likely due to low training intensity, and efforts should be made to improve quality of unsupervised training, such as providing motivational coaching and wearable exercise trackers.