Feasibility and adherence to moderate intensity cardiovascular fitness training following stroke: a pilot randomized controlled trial

BACKGROUND: Stroke is a leading cause of disability worldwide and the cardiovascular fitness levels of stroke survivors are diminished to an extent that impairs functioning and activities of daily living performance. While cardiovascular training seems an empirically appropriate intervention, the optimal dosage and intensity of cardiovascular training in stroke survivors remains unclear. The aim was to determine the safety and feasibility of moderate-intensity cardiovascular training following stroke, including measurement of adherence to training. METHODS: A pilot, prospective, patient- and assessor-blinded randomised controlled trial conducted in a tertiary, metropolitan hospital-based community rehabilitation centre. Eligibility criteria included ambulant (> 100 m), 6 weeks-12 months post stroke. Moderate-intensity fitness training or control (low-intensity) exercise was offered biweekly for 12 weeks. Outcome measures included adverse events, peak oxygen uptake (VO(2)), functional exercise capacity (6-Minute Walk Test, 10-m Walk Test) and health-related quality of life (Short Form-36) and mood (Patient Health Questionnaire, PHQ9). RESULTS: Feasibility: Seventy-one (50%) of 141 screened participants were eligible (29% did not agree to participate). Twenty participants (10 intervention, 10 control) were recruited. The median (%; IQR) supervised sessions was 19.5 (81%; 12, 20); and 20 (83%; 19, 22) in the intervention and control groups, respectively. Progression of duration and intensity was limited; mean of 10 sessions to achieve target duration (30 min). There were no adverse events. Baseline peak oxygen uptake (VO(2)) levels were low (15.94 ml/kg/min). Significant improvements in VO(2) peak in both groups were observed (p < 0.05). Although there were no significant between-group differences, this feasibility trial was not powered to detect change. CONCLUSIONS: Moderate-intensity fitness training was safe but achievement of target duration and intensity was challenging for stroke survivors. A definitive adequately-powered randomised trial is required. Alternative fitness training protocols may need to be explored. TRIAL REGISTRATION: The trial protocol was prospectively registered on the Australian New Zealand Clinical Trials Registry (ACTRN 12613000822785) on 25/07/2013. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12883-021-02052-8.