AzTrials
AzTrials

ME/CFSME/CFSNCT07454395

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

A study testing Swimming and Cycling in people with ME/CFS and Long COVID, run by Simon Fraser University at 1 site in Canada.

Suspended

Paused. Enrolment is on hold for now and may resume.

Official record
Search all trials

Trial 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… Read more about this study

Who is it for?
Ages 18 to 80 yearsHealthy volunteers can take part
Conditions the study is for
ME/CFS, Long COVID, Post- COVID-19 Syndrome
What is being tested?
Swimming and Cycling
Could I receive a placebo?
No, everyone receives an active treatment
How many people
50 participants
Where
1 siteCanada
Study dates
20 Feb 2026to Jun 2027
Phase
Interventional
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 80 years
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Who may be able to join

  • Be between the ages of 18-80
  • Meet the criteria of (ME/CFS). The diagnostic criteria for ME/CFS according to the primary Canadian Consensus Criteria are: 1. Fatigue (significant physical and mental fatigue that is new onset, unexplained, persistent or recurrent, and substantially reduces activity level), 2. Post-exertional malaise and/or post-exertional fatigue (general feeling of discomfort, weakness and/or fatigue, and potentially worsening associated symptoms, following physical or mental exertion; slow recovery which is usually longer than 24 hours), 3. Sleep dysfunction (unrefreshing sleep or disturbances in sleep quantity or rhythm), and 4. Pain (significant degree of muscle and/or joint pain, and/or significant headaches of new type, pattern or severity). This may include individuals with (but not limited to) Post-Viral Fatigue Syndrome, Long-Covid 19, Overtraining Syndrome (OTS), and/or co-occurring Postural Orthostatic Tachycardia Syndrome (POTS), Fibromyalgia, and/or Mast Cell Activation Syndrome (MCAS).
  • Experience some degree of post exertional malaise and have some degree of exercise intolerance upon physical exertion.
  • Must have been previously physically active and be able to swim
  • Must be considered moderate-to-mild CFS (not severe or very severe) with a FUNCAP27 score between 3.0-5.8.
  • Must be able to do some light physical activity and go to public places without causing post-exertional malaise.
  • Be between the ages of 18-80
  • Must be physically active and be able to swim.

Who cannot join

  • Individuals with cardiovascular, pulmonary, metabolic, renal, endocrine, autoimmune, neurological, inflammatory condition, infectious disease, or mental illness that makes exercise participation a risk will be excluded from the study.
  • Individuals who are pregnant will be excluded from the study.
  • Individuals with musculoskeletal injuries that prevent exercise participation will be excluded from the study

Trial locations and contacts

1 site in 1 country.

Canada1 site
  • Simon Fraser University

    Burnaby, British Columbia, V5A 1S6

Other trials in Canada

About this study

Official title: Investigating the Effect of Swimming on Autonomic and Symptomatic Responses in 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]

Read the 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.

Being tested
Swimming, Cycling
Keywords
swimming, ME/CFS, HRV, Visible App, long-covid
Medical subject headings
Fatigue Syndrome, Chronic, Post-Acute COVID-19 Syndrome, Postural Orthostatic Tachycardia Syndrome, Fibromyalgia, Overtraining Syndrome, Mast Cell Activation Syndrome

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • SwimmingBehavioural

    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.

  • CyclingBehavioural

    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.

Study groups in NCT07454395
Study groupRoleWhat they receive
ME/CFS groupExperimentalIndividuals with ME/CFS and related conditions
Receives: Behavioral: Swimming; Behavioral: Cycling
Control GroupActive comparatorHealthy age and sex matched controls
Receives: Behavioral: Swimming; Behavioral: Cycling

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Symptoms

    Daily symptoms will be recorded in the Visible app each evening as part of the evening check-in. All available symptoms listed on the app will be evaluated (44 items, rated 0-3, with 0=none, and 3= severe). The total score will be the sum of all 44 items.

    Measured: From enrollment until minimally three days post final exercise session (11~15 days total)

  2. Heart Rate Variability

    HRV will be collected each morning upon waking, and in the seated-upright position, through the Visible application. This is assessed with lnRMSSD plotted on a 0-100 scale. Analyses will focus on changes in HRV from baseline to 24, 48, and 72 hours post-swim session compared to post-bike session.

    Measured: From enrollment until minimially three days after one or both exercise sessions (11~15 days total)

Secondary outcomes (3)
  1. Time to recovery

    The time to recovery from each exercise session will be assessed. This will be defined as the number of days it takes for the readiness scores to reach at least a 4 out of 5 on the Visible App.

    Measured: From enrollment to the post-exercise recovery periods from days ~9-11 and ~13-15.

  2. Exercise Load

    The intensity and duration of the exercise sessions will be determined as the duration of the exercise in minutes multiplied by the rating of perceived exertion for the session (sRPE) on a Borg 0-10 scale.

    Measured: Exercise days ~8 and ~12.

  3. Severity of ME/CFS

    The functional capacity 27 scale will be used to assess the functional severity of each participant's condition. The scale has 27 statements, that are ranked from on a likert scale of 0-6, with 0 being "unable to perform that activity", and 6 being "unproblematic - does not affect other activities." The average score from all 27 statements is used as the overall score. Only participants with a score ≥3.0 and <5.8 will be included in the study (representing mild-to-moderate ME/CFS).

    Measured: Baseline

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted6 Mar 2026
  2. Study start20 Feb 2026
  3. Primary completionJan 2027 (estimated)
  4. Study completionJun 2027 (estimated)

Why it stopped: The research ethics board suspended the study to investigate a complaint from a community member who is not enrolled in the study. This community member is worried about exercise in this population.There have been no complaints from participants.

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Supportive care
Allocation
Non-randomised
Intervention model
Crossover
Model description
This is non-randomized cross-over design. A healthy age and sex matched control group will perform the same intervention to understand the healthy response to the interventions.
Masking
None (open label)
Enrolment
50 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07454395
Sponsor's protocol ID
30003523
Other IDs
n2cx3
Acronym
ME/CFS
Status last verified
Mar 2026
First submitted
25 Feb 2026
Last updated
30 Mar 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Publications

  • Arron HE, Marsh BD, Kell DB, Khan MA, Jaeger BR, Pretorius E. Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: the biology of a neglected disease. Front Immunol. 2024 Jun 3;15:1386607. doi: 10.3389/fimmu.2024.1386607. eCollection 2024.

    PubMed 38887284
  • Kooshki M, Rezeai-Farimani R, Moradpour A, Baradaran Rahimi V, Askari VR. How Swimming Modulates Inflammatory Pathways in Pain, Neurodegenerative, and Metabolic Disorders. Brain Sci. 2025 Oct 18;15(10):1121. doi: 10.3390/brainsci15101121.

    PubMed 41154214
  • Sommerfelt K, Schei T, Seton KA, Carding SR. Assessing Functional Capacity in Myalgic Encephalopathy/Chronic Fatigue Syndrome: A Patient-Informed Questionnaire. J Clin Med. 2024 Jun 14;13(12):3486. doi: 10.3390/jcm13123486.

    PubMed 38930014
  • Sawyer A, Preston R, Leeming H, Martin-Fuller L, Proal A, Putrino D. Wearable technology in the management of complex chronic illness: preliminary survey results on self-reported outcomes. Front Digit Health. 2025 Oct 8;7:1662255. doi: 10.3389/fdgth.2025.1662255. eCollection 2025.

    PubMed 41132394
  • Vernon SD, Funk S, Bateman L, Stoddard GJ, Hammer S, Sullivan K, Bell J, Abbaszadeh S, Lipkin WI, Komaroff AL. Orthostatic Challenge Causes Distinctive Symptomatic, Hemodynamic and Cognitive Responses in Long COVID and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Front Med (Lausanne). 2022 Jun 23;9:917019. doi: 10.3389/fmed.2022.917019. eCollection 2022.

    PubMed 35847821
  • Joseph P, Pari R, Miller S, Warren A, Stovall MC, Squires J, Chang CJ, Xiao W, Waxman AB, Systrom DM. Neurovascular Dysregulation and Acute Exercise Intolerance in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Randomized, Placebo-Controlled Trial of Pyridostigmine. Chest. 2022 Nov;162(5):1116-1126. doi: 10.1016/j.chest.2022.04.146. Epub 2022 May 6.

    PubMed 35526605

Questions about this trial

What is this clinical trial studying?

A study testing Swimming and Cycling in people with ME/CFS and Long COVID, run by Simon Fraser University at 1 site in Canada.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 8 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: paused, as of the sponsor's last update on 30 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Canada. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

Results are not available in the source record.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Symptoms (time frame: From enrollment until minimally three days post final exercise session (11~15 days total)). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT07454395, which also lists 6 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 30 Mar 2026.

Free account

Log in to keep searching

You’ve used your 3 free searches. AzTrials is free: log in or create a free account to keep searching clinical trials and save the ones you want to follow.

Create a free accountLog in