Effect of High-Intensity Interval Training and Moderate-Intensity Continuous Training in People With Poststroke Gait Dysfunction: A Randomized Clinical Trial
Question
Do conventional moderate-intensity continuous training and a novel high-intensity interval training program have different effects on peak oxygen uptake and 6-minute walk distance in people with poststroke gait dysfunction?
Summary
In a 24-week randomized trial of 47 people with poststroke gait dysfunction, replacing three of five weekly moderate continuous walking sessions with high-intensity interval treadmill sessions produced a larger improvement in peak oxygen uptake than continuing five weekly moderate continuous sessions. Both groups improved 6-minute walk distance similarly. The HIIT program was delivered in a screened rehabilitation setting with treadmill harness support, heart-rate monitoring, supervised sessions, and a four-week preparatory phase.
Methodology
- Forty-seven people with poststroke gait dysfunction randomized to HIIT plus MICT or MICT in a rehabilitation program.
- 47 participants.
- Mostly treadmill walking with harness and handrail support; occasional overground walking.
- Work intervals: 30 seconds in workout 1; 2 minutes in workout 2.
- Recovery: 60 seconds active recovery in workout 1; 3 minutes active recovery in workout 2.
- Intensity: Maximal safe/tolerable treadmill speed and grade, guided by RPE >=17, >=91% peak oxygen uptake workload/heart rate, and above ventilatory threshold.
- Approximately 20-22 minutes plus 5-minute warmup and 5-minute cooldown.
- 3 HIIT sessions/week plus 2 MICT sessions/week during weeks 5-24.
- 24 weeks total, with 20 weeks of HIIT after a 4-week preparatory phase.
- 24-week, two-arm, parallel-group superiority randomized clinical trial
- Peak oxygen uptake, 6-minute walk distance, Oxygen uptake at ventilatory anaerobic threshold, and Adverse events were tracked.
Outcomes
Peak oxygen uptake
HIIT improved peak oxygen uptake more than MICT: 5.7 +/- 3.1 versus 2.4 +/- 2.7 mL/kg/min, a relative change of 30 +/- 18% versus 13 +/- 15%.
Adjusted mean difference 3.2 mL/kg/min, 95% CI 1.5 to 4.8, P < 0.001, partial eta squared 0.212
6-minute walk distance
Both groups improved, but between-group difference was not significant: HIIT 83.4 +/- 53.6 m versus MICT 70.9 +/- 44.3 m.
Mean difference 12.5 m, 95% CI -17 to 42, P = 0.401, partial eta squared 0.005
Ventilatory anaerobic threshold oxygen uptake
HIIT produced a greater increase than MICT.
Mean difference 2.07 mL/kg/min, 95% CI 0.59 to 3.6, P = 0.008, partial eta squared 0.197
Secondary outcomes
No other significant between-group differences were observed across gait speed, gait economy, cognition, balance, stair climb, strength, and quality of life.
Safety
No study-related serious adverse events occurred; adverse events occurred in both groups and severe events were not intervention-related.
33 AEs in 23 participants; HIIT 16 AEs in 10/24 participants, MICT 17 AEs in 13/23 participants
Insights
- In screened poststroke rehabilitation, adding three weekly HIIT sessions to a five-session weekly aerobic program can produce greater CRF gains than all-MICT training.
- Functional walking gains may not track directly with CRF gains; MICT at ventilatory threshold produced similar 6MWD improvement.
- Clinical HIIT protocols may require a foundation phase, objective intensity testing, fall protection, and active monitoring.
- A combination of short 30-second intervals and longer 2-minute intervals is feasible in a supervised treadmill setting.
Limitations
- Single-center trial
- Small sample and stopped before revised recruitment target because of COVID-19 restrictions
- 6MWD and secondary outcome assessors were not blinded
- Clinical poststroke population and supervised treadmill/harness setting limit consumer generalizability
- full paper extraction did not use supplemental protocol tables
Safety
- No study-related serious adverse events.
- Adverse events were queried at each visit and graded with Common Terminology Criteria for Adverse Events.
- Harness support, handrail support, and supervised heart-rate monitoring were part of the delivery context.
- Severe adverse events included bowel bleed, falls, orthostatic hypotension, gall bladder surgery, and kidney stones, all reported as not intervention-related.