Preliminary outcomes of combined treadmill and overground high-intensity interval training in ambulatory chronic stroke

Introduction: Locomotor high-intensity interval training (HIIT) is a promising intervention for stroke rehabilitation that typically involves bursts of fast treadmill walking alternated with recovery periods. However, overground translation of treadmill speed gains has been somewhat limited, some important outcomes have not been tested and baseline response predictors are poorly understood. This pilot study aimed to guide future research by assessing preliminary outcomes of combined overground and treadmill HIIT. Methods: Ten participants >6 months post stroke completed a multi-domain assessment battery before and after a 4-week no-intervention control phase, then again after a 4-week treatment phase involving 12 sessions of overground and treadmill HIIT. The primary analyses assessed relative changes in overground and treadmill walking speeds after HIIT, evaluated responsiveness of different outcome measures and estimated effects of baseline gait speed on treatment response. Results: Overground and treadmill gait function both improved during the treatment phase relative to the control phase, with overground speed changes averaging 61% of treadmill speed changes (95% CI: 33-89%). Moderate or larger effect sizes were observed for measures of gait performance, balance, fitness, cognition, fatigue, perceived change and brain volume. Participants with baseline comfortable gait speed <0.4 m/s had less absolute improvement in walking capacity but similar proportional and perceived changes. Discussion: Future locomotor HIIT studies should consider including: 1) both overground and treadmill training; 2) measures of cognition, fatigue and brain volume, to complement typical motor & fitness assessment; and 3) baseline gait speed as a covariate.

Download Full-text

High-Intensity Interval Training and Moderate-Intensity Continuous Training in Ambulatory Chronic Stroke: Feasibility Study

Physical Therapy ◽

10.2522/ptj.20150277 ◽

2016 ◽

Vol 96 (10) ◽

pp. 1533-1544 ◽

Cited By ~ 40

Author(s):

Pierce Boyne ◽

Kari Dunning ◽

Daniel Carl ◽

Myron Gerson ◽

Jane Khoury ◽

...

Keyword(s):

Adverse Events ◽

High Intensity ◽

Ventilatory Threshold ◽

Interval Training ◽

Chronic Stroke ◽

Moderate Intensity ◽

Walk Test ◽

High Intensity Interval Training ◽

Treadmill Speed ◽

High Intensity Interval

AbstractBackgroundPoststroke guidelines recommend moderate-intensity, continuous aerobic training (MCT) to improve aerobic capacity and mobility after stroke. High-intensity interval training (HIT) has been shown to be more effective than MCT among healthy adults and people with heart disease. However, HIT and MCT have not been compared previously among people with stroke.ObjectiveThe purpose of this study was to assess the feasibility and justification for a definitive randomized controlled trial (RCT) comparing HIT and MCT in people with chronic stroke.DesignA preliminary RCT was conducted.SettingThe study was conducted in a cardiovascular stress laboratory and a rehabilitation research laboratory.PatientsAmbulatory people at least 6 months poststroke participated.InterventionBoth groups trained 25 minutes, 3 times per week, for 4 weeks. The HIT strategy involved 30-second bursts at maximum-tolerated treadmill speed alternated with 30- to 60-second rest periods. The MCT strategy involved continuous treadmill walking at 45% to 50% of heart rate reserve.MeasurementsMeasurements included recruitment and attendance statistics, qualitative HIT acceptability, adverse events, and the following blinded outcome variables: peak oxygen uptake, ventilatory threshold, metabolic cost of gait, fractional utilization, fastest treadmill speed, 10-Meter Walk Test, and Six-Minute Walk Test.ResultsDuring the 8-month recruitment period, 26 participants consented to participate. Eighteen participants were enrolled and randomly assigned to either the HIT group (n=13) or the MCT group (n=5). Eleven out of the 13 HIT group participants attended all sessions. Participants reported that HIT was acceptable and no serious adverse events occurred. Standardized effect size estimates between groups were moderate to very large for most outcome measures. Only 30% of treadmill speed gains in the HIT group translated into overground gait speed improvement.LimitationsThe study was not designed to definitively test safety or efficacy.ConclusionsAlthough further protocol optimization is needed to improve overground translation of treadmill gains, a definitive RCT comparing HIT and MCT appears to be feasible and warranted.

Download Full-text