Does exercise tolerance testing at 60 days poststroke predict rehabilitation performance?

Objective: To assess the relationship between exercise tolerance test (ETT) performance at 6 weeks poststroke and subsequent performance in a treadmill and overground locomotor training program (LTP). Design: Prospective cohort study. Setting: Exercise testing laboratory in either a primary care hospital or outpatient clinic. Participants: Community-dwelling individuals (N=469), 54.9±19.0 days poststroke, enrolled in the Locomotor Experience Applied Post-Stroke randomized controlled trial. Interventions: Not applicable. Main Outcome Measures: For participants randomly assigned to LTP, the number of sessions needed to attain the training goal of 20 minutes of treadmill stepping was determined. Regression analyses determined the contribution of ETT performance (cycling duration), age, and 6-minute walk test (6MWT) distance to attainment of the stepping duration goal. Results: Age, 6MWT, and ETT performance individually accounted for 10.74%, 10.82%, and 10.76%, respectively, of the variance in the number of sessions needed to attain 20 minutes of stepping. When age and 6MWT were included in the model, the additional contribution of ETT performance was rendered nonsignificant (P=.150). Conclusions: To the extent that ETT performance can be viewed as a measure of cardiovascular fitness rather than neurologic impairment, cardiovascular fitness at the time of the ETT did not make a significant unique contribution to the number of sessions needed to achieve 20 minutes of stepping. The 6MWT, which involves less intensive exercise than the ETT and therefore is likely to be predominantly affected by neurologic impairment and muscular condition, appeared to account for as much variance as the ETT.