# Effects of high-intensity interval training versus moderate-intensity continuous training on cardiorespiratory function in patients after stroke: a systematic review and meta-analysis of randomized trials

## TL;DR

This study compares high-intensity interval training and moderate-intensity continuous training in stroke patients, finding that high-intensity training improves cardiorespiratory fitness more effectively.

## Contribution

The study provides the first meta-analysis comparing HIIT and MICT effects on cardiorespiratory outcomes in post-stroke patients.

## Key findings

- HIIT improved V̇O2-peak and VO2-VT more than MICT in stroke patients.
- HIIT did not enhance mobility outcomes like walking endurance or balance more than MICT.
- HIIT resulted in higher heart rate during training sessions compared to MICT.

## Abstract

Whether high-intensity interval training (HIIT) is more effective than moderate-intensity continuous training (MICT) in improving cardiorespiratory fitness (CRF) among patients after stroke remains unclear. We conducted this systematic review and meta-analysis to investigate the effects of HIIT versus MICT on CRF.

We performed a literature search in the PubMed, Embase, and Cochrane Library from their earliest publication record to February 2025. Randomized trials comparing the outcomes of HIIT and MICT in patients after stroke were included. The mean difference (MD) and standardized mean difference (SMD) were determined by pooling the means and standard deviations of pretreatment–posttreatment changes for the CRF outcomes [i.e., oxygen consumption at peak (V̇O2-peak) and at ventilation threshold (VO2-VT)], mobility outcomes (i.e., walk endurance, speed, and postural balance) and training fidelity parameters (i.e., peak and mean heart rate during training sessions).

Nine articles, encompassing eight trials and a total of 371 patients, were included in the analysis. The meta-analysis revealed that HIIT was more effective in improving V̇O2-peak (MD = 1.88 mL/kg/min, 95% CI: 1.20 to 2.55, p < 0.05) and VO2-VT (MD = 2.20 mL/kg/min, 95% CI: 0.46 to 3.95, p < 0.05). However, HIIT did not show greater effectiveness in improving the 6-min walk test, 10-meter gait speed, or Berg Balance Score. Regarding training fidelity, a significantly higher mean heart rate [measured as a percentage of heart rate reserve (HRR, %)] was observed in HIIT sessions (MD = 19.36% HRR, 95% CI: 13.83 to 24.90, p < 0.05).

HIIT is more effective than MICT in improving V̇O2-peak and VO2-VT in patients after stroke, supporting HIIT may serve as an alternative for aerobic training in this population.

https://www.crd.york.ac.uk/PROSPERO/view/CRD42025645342, CRD42025645342.