NCT05445830

Exercise Intolerance in Post-COVID Patients

Physiological Characterization of Functional Limitations and Exercise Intolerance in Post-COVID Patients

• Status: Active Not Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 62 (actual)
• Sponsor: Karolinska Institutet · Academic / Other
• Sex: All
• Age: 18 Years – 64 Years
• Healthy volunteers: Accepted

Summary

The post-COVID syndrome poses an unprecedented challenge to modern society, affecting millions of people worldwide. Persistent fatigue and exercise intolerance are among the most common complaints of these subjects. The mechanisms of exercise intolerance in post-COVID subjects are remained yet unknown, which make the rehabilitation efforts complex and challenging. The overall goals of this project are to: 1) improve physiological understanding of symptoms in this clinical condition, 2) elucidate plausible mechanisms to explain exercise intolerance/symptom exacerbation, and finally 3) provide knowledge that can be directly applied in the clinical setting to improve diagnosis, care, and individualized rehabilitation of subjects with post-COVID syndrome. Post-COVID subjects and age/sex matched healthy controls will undertake a comprehensive set of physiological and functional assessments, followed by 3 experimental visits (in a randomized order), where acute exercise responses will be assessed in either continuous moderate intensity aerobic exercise, high intensity interval exercise, or strength training. The same set of physiological assessments will also be performed after 1 year in both post-COVID subjects and healthy-matched controls to better understand the time course of the syndrome. It is hypothesized that the mechanism responsible for exercise intolerance is linked to specific symptoms and will vary across subjects. However, it is expected that most post-COVID subjects will respond well to at least one type of exercise.

Conditions

• Post-COVID Syndrome

Interventions

Type	Name	Description
PROCEDURE	High-Intensity-Interval-Exercise	Subjects will perform high-intensity-interval exercise, where the acute exercise responses will be closely monitored, including measurements of O2 saturation, heart rate, blood pressure, borg scale and blood lactate. In addition, symptoms via multiple validated questionnaries and blood samples will be collected before, immediately after each exercise session to describe leukocyte and cytokine release as well as systemic metabolism. After a 48-hour rest period subjects will return to the laboratory for symptom assessment, submaximal exercise response (CPET), and blood sampling.
PROCEDURE	Moderate-Intensity-Continuous-Exercise	Subjects will perform moderate intensity continuous exercise, where the acute exercise responses will be closely monitored, including measurements of O2 saturation, heart rate, blood pressure, borg scale and blood lactate. In addition, symptoms via multiple validated questionnaries and blood samples will be collected before, immediately after each exercise session to describe leukocyte and cytokine release as well as systemic metabolism. After a 48-hour rest period subjects will return to the laboratory for symptom assessment, submaximal exercise response (CPET), and blood sampling.
PROCEDURE	Strength training	Subjects will perform a series of a whole-body resistance exercises, where the acute exercise responses will be closely monitored, including measurements of O2 saturation, heart rate, blood pressure, borg scale and blood lactate. In addition, symptoms via multiple validated questionnaries and blood samples will be collected before, immediately after each exercise session to describe leukocyte and cytokine release as well as systemic metabolism. After a 48-hour rest period subjects will return to the laboratory for symptom assessment, submaximal exercise response (CPET), and blood sampling.
PROCEDURE	Baseline assessment	Subjects will perform a series of baseline assessment including neurophysiological function, circulatory and vascular function, blood volume assessment, respiratory/ventilatory function, maximal oxygen uptake, strength, physical function and fitness, blood status and muscle biopsy.
PROCEDURE	1 year follow-up	Subjects will perform the same series of baseline assessment in 1-year time, including neurophysiological function, circulatory and vascular function, blood volume assessment, respiratory/ventilatory function, maximal oxygen uptake, strength, physical function and fitness, blood status and muscle biopsy.

Timeline

• Start date: 2022-09-01
• Primary completion: 2023-09-15
• Completion: 2025-12-31
• First posted: 2022-07-06
• Last updated: 2025-09-03

Locations

1 site across 1 country: Sweden