Trials / Suspended

SuspendedNCT07454395

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

Investigating the Effect of Swimming on Autonomic and Symptomatic Responses in Individuals With Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Status: Suspended
Phase: N/A
Study type: Interventional
Enrollment: 50 (estimated)

Sponsor: Simon Fraser University · Academic / Other
Sex: All
Age: 18 Years – 80 Years
Healthy volunteers: Accepted

Summary

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. \[Note: this is not an exercise training or rehabilitation study, and participation is only intended for individuals who can tolerate some gentle activity and can be in public spaces without triggering post-exertional malaise. You should be comfortable with swimming, but flotation or other assistive devices are welcome\]

Detailed description

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating multisystem disorder characterized by extreme fatigue, sleep dysfunction, pain, and post-exertional malaise and/or post-exertional fatigue, and is accompanied by orthostatic intolerance, and neuroendocrine and immune manifestations. The defining feature of ME/CFS is the delayed onset (\~12-48 h) exacerbation of symptoms following physical, cognitive, orthostatic, and even emotional exertion, termed post-exertional malaise (PEM). As such, despite the known benefits of exercise for improving function in most disease states including other multisystem inflammatory disorders like sepsis, exercising with ME/CFS is generally contraindicated to avoid a worsening of the condition. It has been demonstrated that neurovascular dysregulation underlies much of the exercise intolerance in ME/CFS. When neurovascular function is normalized with pharmacologic cholinergic stimulation in ME/CFS patients performing upright cycling exercise, cardiac output, right atrial pressures, and maximal oxygen consumption are improved, possibly preventing post-exertional malaise. Water immersion can also be used to normalize cardiac output and right atrial pressures, as the prone/supine postures and hydrostatic pressure of the water act to passively encourage venous return. Furthermore, the human dive reflex (when the face is submerged in cool water) increases parasympathetic activation to the heart, slowing down heart rate. There is also evidence of anti-inflammatory effects of swimming in patients with cardiovascular, neurological, and rheumatological diseases, which could also improve inflammation in ME/CFS patients. The purpose of this study is to determine whether light-to-moderate swimming may be a more tolerable form of movement for individuals with ME/CFS.

Conditions

Interventions

Type	Name	Description
BEHAVIORAL	Swimming	Following a week of baseline HRV and symptoms tracking, all participants will be asked to perform a light swimming session. This session should be at a self-selected intensity and duration, however it should always be performed at an intensity that is under a rating of perceived exertion of 5/10 (easy to moderate at most). Recommended duration is \~15-30 min. Participants may use flotation or assistive devices as they wish. Cool water is recommended.
BEHAVIORAL	Cycling	After a minimum of three days of recovery following swimming, and once the visible application indicates a stable recovery score of at least 4/5 (and the participant feels okay), they may optionally complete a cycling session on a stationary bike. This biking session will also be at a self-selected duration and intensity (effort \<5/10), which does not need to match the first session. If participants feel that they are unable to complete the biking exercise session, they can still participate in the study and only complete the swimming. If they believe that it would exacerbate symptoms and cause harm, they should not do the biking.

Timeline

Start date: 2026-02-20
Primary completion: 2027-01-01
Completion: 2027-06-01
First posted: 2026-03-06
Last updated: 2026-03-30

Locations

1 site across 1 country: Canada

Source: ClinicalTrials.gov record NCT07454395. Inclusion in this directory is not an endorsement.