Addition of high-intensity interval training to a moderate intensity continuous training cardiovascular rehabilitation program after ischemic cerebrovascular disease: A randomized controlled trial
Question
Does adding progressive supervised HIIT to a MICT cardiovascular rehabilitation program improve cardiorespiratory fitness, cardiovascular risk factors, physical function, cognition, and depression/anxiety markers more than MICT alone or usual care after ischemic stroke or TIA?
Summary
This randomized trial compared a 6-month combined HIIT plus MICT program, a MICT-only program, and usual care in community-dwelling adults after ischemic stroke or TIA. Both exercise programs improved estimated VO2peak by about 3 ml/kg/min compared with control, and benefits partly persisted 6 months after intervention. Adding supervised HIIT to MICT was safe and acceptable but did not outperform MICT alone.
Methodology
- Community-dwelling adults after ischemic stroke or TIA, ambulatory for more than 10 minutes and not in formal rehabilitation.
- 52 participants.
- Supervised upright ergocycle HIIT plus home-based MICT.
- Work intervals: 30 to 60 seconds at 95% PPO.
- Recovery: 60 seconds passive initially, then active at 40% PPO after 1 month.
- Intensity: 95% PPO for HIIT work bouts; 40% PPO for active recovery, warm-up, and cool-down; home MICT RPE 4-6/10.
- 20 to 40 minutes, including 5-minute warm-up and 5-minute cool-down.
- 3 aerobic sessions per week, with supervised HIIT frequency decreasing from 3/week to 1/week across the program.
- 6 months.
- Three-arm randomized controlled trial with 12-month follow-up
- Estimated VO2peak, Peak power output, Blood pressure, and Lipids and HbA1c were tracked.
Outcomes
Estimated VO2peak
Both HIIT + MICT and MICT increased estimated VO2peak by about 3 ml/kg/min at T6, with some persistence at T12, while control decreased.
Group x Time interaction F = 9.222, df1 = 4, df2 = 72, p < 0.001; HIIT + MICT 18.9 to 21.9 to 20.6 ml/kg/min; MICT 21.1 to 24.1 to 22.5; control 19.3 to 18.7 to 18.0.
Peak power output
Both exercise groups increased PPO at T6 and remained above baseline at T12, while control decreased.
Group x Time interaction F = 10.522, df1 = 4, df2 = 72, p < 0.001; HIIT + MICT 83.3 to 105.3 to 96.0 W; MICT 99.2 to 119.2 to 108.3 W; control 80.0 to 76.7 to 72.5 W.
HIIT + MICT superiority over MICT
The combined HIIT + MICT program did not show superiority over MICT alone; most interaction variance reflected exercise groups versus control.
Authors reported 99.6% of VO2peak and 98.5% of PPO Group x Time interaction variance due to merged exercise groups versus control, leaving quasi-null interaction variance between exercise groups.
Self-reported physical activity and anxiety/depression
Both exercise programs increased self-reported physical activity and decreased anxiety and depression markers compared with control patterns.
Article reports comparable increases/decreases; detailed table values vary by outcome.
Safety
No adverse events were registered during the exercise programs.
0 registered adverse events in exercise programs.
Attendance
Supervised attendance was high in both exercise groups; home attendance was more variable.
Supervised attendance 95% (79-100%) for HIIT + MICT and 93% (77-100%) for MICT; home attendance 78 +/- 23% and 82 +/- 18%; no between-group attendance difference, p > 0.05.
Cardiovascular risk factors
Blood pressure, lipids, HbA1c, waist circumference, and body composition did not show consistent exercise-driven improvements.
Authors note baseline values were generally in therapeutic targets and results did not support improvement in these factors.
Insights
- In post-stroke/TIA rehabilitation, adding supervised HIIT to MICT may be safe and acceptable but should not be assumed superior to MICT alone.
- Progressive HIIT introduction after an initial moderate week is a practical safety pattern for clinical populations.
- Home moderate aerobic sessions can complement supervised clinical sessions, but self-reported home adherence may vary widely.
- For clinical users, program choice may reasonably depend on patient preference, supervision access, and adherence rather than presumed HIIT superiority.
Limitations
- Voluntary sample may create selection bias
- Dropouts excluded from acceptability analysis
- Limited sample size for some outcomes
- Home exercise was self-reported and guided by perceived exertion
- The study did not directly compare pure HIIT with pure MICT
- Exercise interventionist could not be blinded
- Sample was heterogeneous for age, time since stroke, TIA inclusion, and comorbidities
- No participants with major motor impairments
Safety
- No adverse events were registered during exercise programs.
- HIIT was performed under clinical supervision because of high-risk post-stroke/TIA status and ethical approval considerations.
- Blood pressure and heart rate were monitored during supervised sessions with defined stop thresholds.