Related Experiment Video
Updated: May 7, 2026
A Real-World High-Intensity Interval Training Protocol for Cardiorespiratory Fitness Improvement
Published on: February 22, 2022
Home-Based Supervised Cardiorespiratory Interval Training Decreases Poststroke Fatigue and Improves Cardiorespiratory
Anna Bråndal1,2, Maria Svedjebrant3,4, Ylva Nilsagård4,5
1Department of Public Health and Clinical Medicine, Umeå University, Sweden (A.B., P.W.).
Background:
Poststroke fatigue (PSF) affects nearly half of all stroke survivors and significantly hinders rehabilitation and daily functioning. There is no established treatment. Low cardiorespiratory fitness may contribute to PSF, suggesting aerobic training as a potential intervention.
Methods:
In this 2-center, randomized, open-label, blinded end point trial, we evaluated a home-based, supervised cardiorespiratory interval training program (HS-CITP) in individuals with PSF (Swedish Fatigue Assessment Scale score ≥28) 1 to 7 months poststroke. Participants were randomized (1:1) to either HS-CITP or usual care with self-directed activity after early supported discharge. The intervention consisted of 35-minute cycling sessions performed 3 times per week at 70% to 80% of maximum heart rate for 8 weeks. The study was powered to detect a 9-point between-group difference on the Swedish Fatigue Assessment Scale. The primary outcome was self-reported fatigue (Swedish Fatigue Assessment Scale score) at 8 weeks (postintervention), and the secondary outcome was peak oxygen uptake (mL/kg per minute) at 8 weeks. Analyses were performed according to the intention-to-treat principle using adjusted between-group comparisons.
Results:
Forty-five participants were randomized; the mean age was 64 years, and 56% were women. Forty-three participants completed the postintervention assessment (HS-CITP: n=22; control: n=21). Adherence to HS-CITP was 92%, and no adverse events were reported. In adjusted analyses, compared with the control group, HS-CITP significantly reduced fatigue (between-group mean difference -5.35 Swedish Fatigue Assessment Scale score points [95% CI -9.03 to -3.67]; P<0.001) and improved cardiorespiratory fitness (+4.48 mL/kg per minute [95% CI, 3.41-5.54]; P<0.001). No significant group-by sex interaction was observed.
Conclusions:
Supervised home-based interval training significantly reduced PSF and improved cardiorespiratory fitness, with good adherence and no safety concerns. These findings support integrating structured aerobic exercise into stroke rehabilitation. Larger, longer-term trials are needed to confirm durability, determine the optimal timing poststroke, and evaluate other exercise modalities.
Registration:
URL: https://www.clinicaltrials.gov; Unique identifier: NCT03458884.
Related Concept Videos
01:17Exercise and Cardiac Output
Sustained exercise increases the muscles' oxygen demand, which can be...
01:22Cardiac Output II: Effect of Stroke Volume on Cardiac Output
Preload
Preload refers to the initial elongation of the cardiac myocytes before contraction and is related to the volume of blood filling the heart at the end of diastole, or end-diastolic volume. The...
01:20Exercise and Cardiovascular Response
Light to moderate physical activity initiates a series of interconnected responses in the body. The heart rate modestly increases in anticipation of the workout, followed by widespread vasodilation as oxygen consumption by skeletal muscles increases. This results in decreased peripheral resistance, increased capillary blood flow, and accelerated...
01:22Heart Failure VI: Adjunct Therapies