Ambulatory activity intensity profiles, fitness, and fatigue in chronic stroke

Purpose: The purpose of this study was to describe household and community ambulatory activity profiles and their relationship to fatigue and cardiovascular fitness in a sample of men and women with chronic hemiparetic stroke. Method: We quantified community-based ambulatory activity profiles in terms of step counts and intensity, along with cardiovascular fitness and fatigue severity, in a convenience sample of 79 men and women with chronic hemiparetic stroke. Results: As captured by daily step activity monitoring, participants demonstrated extremely low step counts (1389 +/- 797 steps/day), and almost no step activity at high intensity (78 +/- 168 steps/day at a rate of >= 30 steps/minute). Mean high intensity activity constituted less than 3 minutes/day. The mean VO2 peak was 13.02 +/- 4.26 mL/kg/min, consistent with profound aerobic deconditioning. Total, low, and high intensity ambulatory activity were associated with VO2 peak. Mean fatigue severity was 3.28 +/- 1.36 on a scale of 7.00, with 42% of the sample reporting severe fatigue. There were no statistically significant correlations between fatigue severity and ambulatory activity or fitness measures. Conclusion: Our results show that step activity intensity is strongly associated with cardiovascular fitness, lending credence to the hypothesis that rehabilitation interventions that build aerobic conditioning can influence daily activity. The challenge is to appreciate the features of ambulatory behavior after stroke and to use this information to integrate both exercise interventions and behavioral components into the successful translation of structured activities into home and community routines.