High-Intensity Interval Training (HITT) in Rehabilitation

High-Intensity Interval Training (HIIT) is gaining traction in rehabilitation, and for good reason. Across neurological, cardiovascular, and pulmonary populations, HIIT has consistently demonstrated superior improvements in cardiorespiratory fitness, functional capacity, and quality of life when compared to traditional moderate-intensity continuous training.

Yet despite the evidence, many clinicians hesitate to implement HIIT due to safety concerns, protocol confusion, or uncertainty around patient selection. This article breaks down what HIIT is, who benefits most, and how to apply it safely and effectively in clinical practice.

What is HIIT?

HIIT is an exercise strategy that alternates brief bouts of high-intensity effort (typically 80–100% workload) with periods of low-intensity exercise or rest.

In rehabilitation settings, HIIT serves as an alternative pathway to reach intensity thresholds required for:

• Meaningful cardiovascular adaptations

• Cerebrovascular improvements

• Neuroplastic changes

Notably, HIIT has been shown to outperform moderate continuous training for improving VO₂ peak and functional outcomes across multiple rehab populations.

Patient Populations that Benefit Most from HIIT

Neurological Conditions

• Stroke

• Parkinson’s disease

• Multiple sclerosis

• Non-complete spinal cord injury

• Traumatic brain injury

Cardiovascular Conditions

• Coronary artery disease

• Heart failure

• Hypertension

• Peripheral artery disease

• Post-MI / post-CABG

Pulmonary Conditions

• COPD

• Asthma

• Pulmonary hypertension

Across these groups, HIIT has demonstrated improvements in aerobic capacity, gait performance, balance, and perceived energy levels.

HIIT in Neurological Rehabilitation

In neurological populations including stroke, Parkinson’s disease, multiple sclerosis, non-complete spinal cord injury, and traumatic brain injury, HIIT aligns closely with established principles of neuroplasticity, including intensity, repetition, specificity, and salience.

HIIT has been associated with:

• Improved gait speed and walking endurance

• Better balance and coordination

• Enhanced motor control through neuroplastic adaptations

• Strong improvements in VO₂ peak and 6MWT performance

By delivering high-intensity, task-relevant movement, HIIT supports both central nervous system adaptation and peripheral conditioning, making it a valuable adjunct to skill-based neurorehabilitation.

HIIT in Cardiovascular Rehabilitation

In cardiovascular populations such as coronary artery disease, heart failure, hypertension, peripheral artery disease, and post-MI or CABG HIIT consistently outperforms moderate continuous training for improving VO₂ peak, a key predictor of morbidity and mortality.

Compared to moderate training, HIIT has been shown to:

• Produce VO₂ improvements comparable to a ~15% reduction in premature mortality

• Improve cardiovascular capacity for daily activities by approximately 35%

• Enhance functional independence and self-perceived energy levels

Given that heart disease remains the leading cause of death in the United States, these improvements have substantial implications for long-term health and quality of life.

HIIT in Pulmonary Rehabilitation

In pulmonary conditions such as COPD, asthma, and pulmonary hypertension, HIIT offers a distinct advantage due to its interval-based structure. Periods of lower-intensity recovery allow patients to tolerate higher overall workloads without excessive symptom burden.

HIIT in pulmonary rehab has been associated with:

• Improved exercise tolerance

• Superior cardiorespiratory fitness gains

• Enhanced quality of life compared to continuous training

This makes HIIT a practical and effective strategy for patients limited by dyspnea or fatigue during sustained activity.

Outcome Measures Most Responsive to HIIT

Strong improvements observed in:

• VO₂ peak

• 6-Minute Walk Test (6MWT)

Variable but positive changes noted in:

• Berg Balance Scale (BBS)

• Timed Up and Go (TUG)

• 10-Meter Walk Test (10MWT)

Most research utilizes treadmill or overground walking, though alternative modalities (e.g., recumbent steppers) have also demonstrated benefit.

Protocols: What Does the Evidence Say?

There is no single standardized HIIT protocol in rehab. Common examples include:

• 30s work / 30s rest at 100% workload for ~36 minutes

• 1–4 minute high-intensity bouts at 80–100% workload with matched recovery

• 2–3 sessions per week for 8–12 weeks

• Total session durations ranging from 20–40 minutes

Key takeaway:
Protocol specifics matter less than achieving and sustaining the appropriate intensity.

Practical Implementation in the Clinic

HIIT should not exist in isolation. It works best when integrated into task-specific, impairment-driven treatment plans.

Examples beyond machines:

• Overground or treadmill walking

• Stairs

• Squats

• Boxing

• Med ball lifts from floor level

Programming principles:

• Target 80–100% intensity

• Start with intervals the patient can tolerate

• Progress by increasing total work time first

• Then bias longer “on” intervals relative to recovery

Parting Words

Across neurological, cardiovascular, and pulmonary rehabilitation, HIIT serves as a high-yield method for improving aerobic capacity, functional performance, and participation. While diagnosis-specific considerations remain important, the unifying factor is intensity and when patients safely reach it, outcomes improve.

HIIT is not a replacement for task-specific or impairment-driven interventions, but when integrated appropriately, it can significantly amplify rehabilitation outcomes.

References

1. Baricich A, Borg MB, Battaglia M, et al. High-Intensity Exercise Training Impact on Cardiorespiratory Fitness, Gait Ability, and Balance in

   Stroke Survivors: A Systematic Review and Meta-Analysis. Journal of Clinical Medicine. 2024;13(18):5498. doi:10.3390/jcm13185498

2. Li S, Dou Y, Li H. Effects of high-intensity exercise on rehabilitation of patients after stroke: a systematic review and meta-analysis of

   randomized controlled trials with high quality. Front Neurol. 2025;16. doi:10.3389/fneur.2025.1565118

3. Brunner IC, Hansen GM. High‐Intensity Gait Training for Patients After Stroke: A Feasibility Study. Physiother Res Int. 2025;30(2):e70059.

   doi:10.1002/pri.70059

4. McGregor G, Powell R, Begg B, et al. High-intensity interval training in cardiac rehabilitation: a multi-centre randomized controlled trial. Eur J Prev Cardiol. 2023;30(9):745-755. doi:10.1093/eurjpc/zwad039

5. Yu H, Zhao X, Wu X, Yang J, Wang J, Hou L. High-intensity interval training versus moderate-intensity continuous training on patient quality of life in cardiovascular disease: a systematic review and meta-analysis. Sci Rep. 2023;13(1):13915. doi:10.1038/s41598-023-40589-5

6. Tian X, Liu F, Li F, Ren Y, Shang H. A Network Meta-Analysis of Aerobic, Resistance, Endurance, and High-Intensity Interval Training to Prioritize Exercise for Stable COPD. COPD. 2024;19:2035-2050. doi:10.2147/COPD.S476256

7. Wang X, Lu J, Niu J, Zhang X, Li M. Effectiveness of high-intensity interval training in rehabilitation nursing for mild-to-moderate stable COPD patients: a randomized controlled clinical trial. BMC Sports Sci Med Rehabil. 2025;17:28. doi:10.1186/s13102-025-01074-w

8. Khushhal A, Nichols S, Carroll S, Abt G, Ingle L. Insufficient exercise intensity for clinical benefit? Monitoring and quantification of a community-based Phase III cardiac rehabilitation programme: A United Kingdom perspective. PLoS One. 2019;14(6):e0217654. doi:10.1371/journal.pone.0217654

9. Butcher SJ, Jones RL. The impact of exercise training intensity on change in physiological function in patients with chronic obstructive pulmonary disease. Sports Med. 2006;36(4):307-325. doi:10.2165/00007256-200636040-00003

10. Nindorera F, Jean-Michel B, Duclos NC, Best KL, Mandigout S, Goncalves S. Exploring physiotherapists’ knowledge and perception of exercise intensity in outpatient stroke rehabilitation: A qualitative study. PLoS One. 2025;20(6):e0325098. doi:10.1371/journal.pone.0325098

11. FastStats. September 17, 2025. Accessed December 11, 2025. https://www.cdc.gov/nchs/fastats/leading-causes-of-death.htm

Disclaimer

We are current Doctor of Physical Therapy (DPT) students sharing information based on our formal education and independent studies. The content presented in this newsletter is intended for informational and educational purposes only and should not be considered professional medical advice. While we strive to provide accurate and up-to-date information, our knowledge is based on our current academic and clinical rotations and ongoing learning, not extensive clinical practice.