Factors associated with change in aerobic capacity following an exercise program for individuals with stroke.

OBJECTIVE: Community exercise programs are effective in improving aerobic capacity after stroke, but individual variability in training responses has not previously been studied. This study examined explanatory factors for post-program responses in aerobic capacity (VO2peak) with respect to training parameters and participant characteristics. DESIGN: Secondary analysis of data from a prospective cohort study. SUBJECTS: Thirty-two participants, mean age 63 years (standard deviation (SD) 13), 29 months (SD 26) post-stroke. METHOD: Following a 6-month community exercise program, multivariate regression analysis was performed to assess for correlates with change in VO2peak with respect to training parameters (exercise duration and intensity) and participant characteristics (lower limb and balance impairment, aerobic and walking capacity). RESULTS: The mean improvement in VO2peak was 11% (SD 19), but individually, changes ranged from 32% decline to 56% improvement. Regression analysis revealed that only 2 variables, baseline aerobic capacity and balance impairment, accounted for the training-related change in VO2peak (R2 = 0.20, p = 0.045). CONCLUSIONS: There is considerable inter-individual variability in stroke exercise program responses in aerobic capacity. Lower baseline aerobic capacity and better balance were associated with greater training-related improvements in VO2peak. Identifying individuals who are more likely to respond to exercise programs may inform future work in establishing effective interventions suited for different subsets of the stroke population.