Is Swimming a More Tolerable Form of Movement for Individuals With Myalgic Encephalomyelitis/ Chronic Fatigue Syndrome?

Individuals with ME/CFS experience profound exercise intolerance and post-exertional malaise. This remote (app-based) pilot study explores whether light, fully self-paced, swimming may be a tolerable form of movement for people with ME/CFS and related conditions, due to the distinct physiological effects of water immersion. The horizontal posture and hydrostatic pressure of water supports venous return and reduces orthostatic stress, while cool water exposure may influence autonomic and inflammatory responses. We are recruiting adults with mild-to-moderate ME/CFS and related conditions for this study examining short-term symptom and autonomic responses to gentle swimming. Participants will choose their own intensity and duration and may stop at any time. A light cycling session is available as an optional comparator for those who feel comfortable doing so. \[Note: this is not an exercise training or rehabilitation study, and participation is only intended for individuals who can tolerate some gentle activity and can be in public spaces without triggering post-exertional malaise. You should be comfortable with swimming, but flotation or other assistive devices are welcome\]

NCT Number	NCT07454395
Lead Sponsor	Simon Fraser University
Conditions	ME/CFS, Long COVID, Post- COVID-19 Syndrome, POTS - Postural Orthostatic Tachycardia Syndrome, Fibromyalgia, Overtraining Syndrome, Post-Viral Fatigue Syndrome, Mast Cell Activation Syndrome
Enrollment	50 participants
Start Date	2026-02-20
Primary Completion	2027-01 (estimated)
Study Completion	2027-06 (estimated)
Updated on ClinicalTrials.gov	2026-03-30