LAUSR

PURPOSE: To investigate the feasibility of aerobic interval training in non-ambulant persons after stroke. METHODS: Intervals of aerobic exercise were performed on a low entry upright (928G3, Monark) or semi-recumbent (RT2, Monark) cycle ergometer depending on individual ability and impairment. Participants were prescribed 4 × 4-minute intervals of exercise at 85%HRmax with a 3-minute active recovery at 70% HRmax between each interval per 30-minute session, 3 times per week for 10 weeks. Heart rate (T31, Polar), rating of perceived exertion (Borg 6–20), workload (W), cadence and duration of exercise achieved were recorded in the last 15 seconds of each interval. Workload was initially prescribed based on data from an incremental cycle ergometer test and, where tolerated, was progressively adjusted to maintain intensity. RESULTS: 9 participants (aged 62±12; 5 male) unable to walk without assistance after stroke (2.9±3.9 years) were recruited. There were no adverse events and 1 drop out (due to Bronchitis). Attendance for the remaining 8 participants was 93±6%. The mean training %HRmax was 72±14% for the higher intensity interval and 57±21%HRmax for the recovery interval, with all participants bar one achieving ≥85%HRmax at least once and the mean number of times being 28±49 over the 120 intervals (30 sessions). The mean increase in training workload between weeks 1 and 10 was 11.2±11.6 W (26.9±27.7%) for the higher intensity interval and 4±7.7W (17.4±33.3%) for the recovery interval. Mean VO2peak was 12.99±4.48mL/kg/min at baseline and 14.62±4.57 mL/kg/min after 10 weeks, showing a mean increase of 1.63±2.43 mL/kg/min (12.5±18.7%) over the 10 week intervention. The mean R-value was 1.09±0.17 at baseline and 1.19±0.19 at outcome while the mean peak HR was 79±16%HRmax at baseline and 79±15%HRmax at outcome. The mean workload was 59±23W at baseline and 78±35W at outcome, showing a mean increase of 17±23W (29±40%). CONCLUSIONS: Aerobic interval training at a moderate-high intensity on an upright or recumbent cycle ergometer is feasible and safe for persons who are non-ambulant after stroke. It should be further researched to investigate its potential to improve cardiorespiratory fitness after stroke and risk-factors for recurrent stroke. Funding body: National Stroke Foundation, Australia