[Skip to Navigation]
Original Investigation
February 23, 2023

Optimal Intensity and Duration of Walking Rehabilitation in Patients With Chronic Stroke: A Randomized Clinical Trial

Author Affiliations
  • 1Department of Rehabilitation, Exercise and Nutrition Sciences, College of Allied Health Sciences, University of Cincinnati, Cincinnati, Ohio
  • 2Department of Neurology, School of Medicine, University of Kansas Medical Center, Kansas City
  • 3Department of Cell Biology and Integrative Physiology, School of Medicine, University of Kansas Medical Center, Kansas City
  • 4University of Kansas Alzheimer’s Research Disease Center, Fairway
  • 5Department of Physical Medicine and Rehabilitation, School of Medicine, University of Kansas Medical Center, Kansas City
  • 6Department of Physical Therapy, College of Health Sciences, University of Delaware, Newark
  • 7Department of Neurology and Rehabilitation Medicine, College of Medicine, University of Cincinnati, Cincinnati, Ohio
  • 8Department of Internal Medicine, College of Medicine, University of Cincinnati, Cincinnati, Ohio
  • 9Department of Cardiology, College of Medicine, University of Cincinnati, Cincinnati, Ohio
  • 10Department of Physical Therapy, Rehabilitation Sciences, and Athletic Training, School of Health Professions, University of Kansas Medical Center, Kansas City
  • 11Division of Biostatistics and Epidemiology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio
  • 12Department of Pediatrics, College of Medicine, University of Cincinnati, Cincinnati, Ohio
JAMA Neurol. 2023;80(4):342-351. doi:10.1001/jamaneurol.2023.0033
Key Points

Question  For walking exercise in patients with chronic stroke, what is the optimal intensity (vigorous vs moderate) and minimum duration (4, 8, or 12 weeks) to maximize immediate improvement in walking capacity?

Findings  In this randomized clinical trial that enrolled 55 stroke survivors, 6-minute walk test gains after 12 weeks of training were 71 m with vigorous training intensity vs 27 m with moderate training intensity, a significant difference. Within the vigorous intensity group, walking capacity significantly increased after each 4-week training block.

Meaning  The findings suggest that optimal dosing for walking exercise for patients with chronic stroke may include at least 12 weeks of training at vigorous intensity.


Importance  For walking rehabilitation after stroke, training intensity and duration are critical dosing parameters that lack optimization.

Objective  To assess the optimal training intensity (vigorous vs moderate) and minimum training duration (4, 8, or 12 weeks) needed to maximize immediate improvement in walking capacity in patients with chronic stroke.

Design, Setting, and Participants  This multicenter randomized clinical trial using an intent-to-treat analysis was conducted from January 2019 to April 2022 at rehabilitation and exercise research laboratories. Survivors of a single stroke who were aged 40 to 80 years and had persistent walking limitations 6 months or more after the stroke were enrolled.

Interventions  Participants were randomized 1:1 to high-intensity interval training (HIIT) or moderate-intensity aerobic training (MAT), each involving 45 minutes of walking practice 3 times per week for 12 weeks. The HIIT protocol used repeated 30-second bursts of walking at maximum safe speed, alternated with 30- to 60-second rest periods, targeting a mean aerobic intensity above 60% of the heart rate reserve (HRR). The MAT protocol used continuous walking with speed adjusted to maintain an initial target of 40% of the HRR, progressing up to 60% of the HRR as tolerated.

Main Outcomes and Measures  The main outcome was 6-minute walk test distance. Outcomes were assessed by blinded raters after 4, 8, and 12 weeks of training.

Results  Of 55 participants (mean [SD] age, 63 [10] years; 36 male [65.5%]), 27 were randomized to HIIT and 28 to MAT. The mean (SD) time since stroke was 2.5 (1.3) years, and mean (SD) 6-minute walk test distance at baseline was 239 (132) m. Participants attended 1675 of 1980 planned treatment visits (84.6%) and 197 of 220 planned testing visits (89.5%). No serious adverse events related to study procedures occurred. Groups had similar 6-minute walk test distance changes after 4 weeks (HIIT, 27 m [95% CI, 6-48 m]; MAT, 12 m [95% CI, −9 to 33 m]; mean difference, 15 m [95% CI, −13 to 42 m]; P = .28), but HIIT elicited greater gains after 8 weeks (58 m [95% CI, 39-76 m] vs 29 m [95% CI, 9-48 m]; mean difference, 29 m [95% CI, 5-54 m]; P = .02) and 12 weeks (71 m [95% CI, 49-94 m] vs 27 m [95% CI, 3-50 m]; mean difference, 44 m [95% CI, 14-74 m]; P = .005) of training; HIIT also showed greater improvements than MAT on some secondary measures of gait speed and fatigue.

Conclusions and Relevance  These findings show proof of concept that vigorous training intensity is a critical dosing parameter for walking rehabilitation. In patients with chronic stroke, vigorous walking exercise produced significant and meaningful gains in walking capacity with only 4 weeks of training, but at least 12 weeks were needed to maximize immediate gains.

Trial Registration  ClinicalTrials.gov Identifier: NCT03760016

Add or change institution
1 Comment for this article
Concerns about baseline walking speed differences improving the 6-minute walking distance
Yuki Nakashima, PT, PhD; Shunsuke Taito, PT, PhD | Division of Rehabilitation, Department of Clinical Practice and Support, Hiroshima University Hospital
We read the article by Boyne et al.[1] with great interest and appreciate the efforts of the authors to describe the effect of high-intensity interval training (HIIT) on a treadmill as compared to moderate-intensity aerobic training (MAT) on improving walking ability and other outcomes in patients with stroke. However, we have reservations about the study.
The difference in distance in the baseline 6-minute walk between HIIT and MAT could have influenced the results. The baseline 6-minute walk distance was approximately 20 meters shorter with the MAT group as compared to the HIIT group, which is a meaningful difference.[2] Previous
studies[3] on treadmill training after stroke have shown that there is little improvement in 6-minute walking distance after the intervention when the baseline walking speed is reduced. Therefore, the authors should provide the results of multivariate analysis along with the type of intervention and baseline walking speed. These results will aid readers in better understanding the true impact of HIIT as compared to MAT.
1. Boyne P, Billinger SA, Reisman DS, et al. Optimal intensity and duration of walking rehabilitation in patients with chronic stroke: A randomized clinical trial. JAMA Neurol Published online February 23, 2023. 2023. doi: 10.1001/jamaneurol.2023.0033.
2. Perera S, Mody SH, Woodman RC, Studenski SA. Meaningful change and responsiveness in common physical performance measures in older adults. J Am Geriatr Soc. 2006;54(5):743-749. doi: 10.1111/j.1532-5415.2006.00701.x.
3. Dean CM, Ada L, Lindley RI. Treadmill training provides greater benefit to the subgroup of community-dwelling people after stroke who walk faster than 0.4m/s: A randomised trial. J Physiother. 2014 June;60(2):97-101. doi: 10.1016/j.jphys.2014.03.004. Epub June 3 2014. PMID: 24952837.