A Whole-Body Exercise Test to Assess Cardiorespiratory Fitness Across the Stroke Recovery Continuum.

BACKGROUND: Accurate assessment of cardiorespiratory fitness is a critical component of cardiopulmonary exercise testing (CPET) and prescription for people with stroke. However, post-stroke disability and neuromuscular impairments are common and may disproportionately affect females throughout the continuum of recovery. There is a need to evaluate alternative whole-body CPET protocols and to characterize the sex-specific CPET responses throughout the continuum of stroke recovery. PURPOSE: To characterize the sex-specific CPET responses on a whole-body recumbent stepper CPET using American College of Sports Medicine (ACSM) criteria in people with subacute (7-90 days) and chronic (≥6-60 months) stroke. METHODS: Participants underwent a whole-body recumbent stepper symptom-limited CPET. Each CPET was assessed for ventilatory threshold (VT), peak oxygen uptake (V̇O2peak) and ACSM maximal oxygen uptake V̇O2max criteria including respiratory exchange ratio [RER] ≥1.10; V̇O2 plateau, heart rate [HR] within 10 beats of HRmax, and ratings of perceived exertion [RPE] ≥17/20 or ≥7/10. Sex differences by stroke chronicity were evaluated via ttests, ranksum tests, Chi-squared, or Fisher's exact tests. RESULTS: In total, 145 participants underwent a symptom limited CPET. In subacute stroke (n=69), no sex differences were found for VT or V̇O2peak (p>0.05), but females were more likely to achieve a V̇O2 plateau (p=0.002). In chronic stroke (n=76), no sex differences were observed for VT or V̇O2max criteria (p>0.05), but females had lower V̇O2peak (p=0.002). Irrespective of sex, achieving the RPE (n=41 subacute [61%], n=38 chronic [54%]) or RER criteria (n=28 subacute [41%], n=39 [51%]) were the most commonly met ACSM criteria. CONCLUSIONS: This whole-body CPET protocol is appropriate for eliciting peak and maximal efforts in people post-stroke, however, clinicians should consider biological sex and stroke chronicity.