Evaluating exercise capacity and symptom triggers in Long COVID patients

Feasibility Study of the Augmented Two-Day 6-Minute Incremental Step Test and Causal Exploration Through a Directed Acyclic Graph and Structural Equation Model for Post-Exertional Symptom Exacerbations in Long COVID Patients

Not applicable Interventional Universitair Ziekenhuis Brussel · NCT06933017

This study is trying to see how well two different exercise tests can help people with Long COVID understand their exercise limits and what triggers their symptoms.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment25 (estimated)
Ages18 Years and up
SexAll
SponsorUniversitair Ziekenhuis Brussel Academic / other
Locations2 sites (Jette, Brussels and 1 other locations)
Trial IDNCT06933017 on ClinicalTrials.gov

What this trial studies

This study evaluates exercise capacity and identifies causes of Post-Exertional Symptom Exacerbation (PESE) in individuals suffering from Long COVID. Participants will undergo two different exercise tests, the Two-Day 6-Minute Incremental Step Test (6MIST) and the Cardiopulmonary Exercise Test (CPET), to compare their effectiveness in detecting PESE. The study will also assess various factors such as metabolism, mitochondrial function, and psychological aspects, using questionnaires and advanced measurement techniques. Each test will be conducted over two consecutive days, with a one-month gap between tests to observe delayed symptom responses.

Who should consider this trial

Good fit: Ideal candidates are adults aged 18 and older who meet the WHO criteria for Long COVID and experience PESE.

Not a fit: Patients with pre-existing conditions that could explain their symptoms or those unable to perform the required exercise tests may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to better understanding and management of Long COVID symptoms, particularly PESE.

How similar studies have performed: While there is ongoing research into Long COVID, this specific approach combining exercise testing and causal modeling is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* ≥18 years old
* Long COVID patients following the World Health Organization (WHO) criteria: "the continuation or development of new symptoms 3 months after the initial SARS-CoV-2 infection, with these symptoms lasting for at least 2 months with no other explanation"
* Previously active as described in the WHO recommendations for physical activity (minimal 150 minutes/week of moderate intensity aerobic physical activity OR minimal 75 minutes of vigorous intensity activity/week OR an equivalent combination of moderate- and vigorous-intensity activity throughout the week)
* Patient suffers from PESE as defined by the DePaul Symptom Questionnaire PEM (Post-Exertional Malaise) subscale
* Able to understand and sign written informed consent in Dutch, French or English

Exclusion Criteria:

* Any pre-existing conditions or new medical diagnosis that can alternatively explain the current symptoms
* Being unable to perform a cycle ergometer test as decided upon by the medical study team members
* Suffering from Chronic Obstructive Pulmonary Disease (COPD) GOLD classification category 2,3 or 4 (by the Global Initiative for Chronic Obstructive Lung Disease)
* Allergies to medical adhesive bandages
* Skin conditions aggravated by sunlight including Porphyria
* Participation in other interventional trials
* Mitochondrial diseases
* Pregnancy
* Lactation

Where this trial is running

Jette, Brussels and 1 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Long COVIDlong covidPEMPost-Exertional MalaiseCPET6MISTFatigue
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.