NCT07323199

High-Intensity Interval Training (HIIT) and Transcranial Direct Current Stimulation (tDCS) in Women With Fibromyalgia - Effects on Clinical and Neuro-physiological Variables: Randomized Clinical Trial Protocol

Not yet recruiting NA Last updated 26 December 2025

What this trial tests

NA trial testing EXERCISE TRAINING WITH OR WITHOUT MEDICATION in Fibromyalgia (FM) in 40 participants. Not yet recruiting.

Timeline

1 January 2026

Primary endpoint
1 September 2026

1 June 2027

Quick facts

Lead sponsor	Universidad Nacional Andres Bello
Phase	NA
Status	Not yet recruiting
Study type	INTERVENTIONAL
Allocation	randomized
Design	parallel
Masking	single
Primary purpose	treatment
Enrollment	40
Start date	1 January 2026
Primary completion	1 September 2026
Estimated completion	1 June 2027
Sites	1 location across Chile

Drugs / interventions tested

• EXERCISE TRAINING WITH OR WITHOUT MEDICATION — full drug profile →
• Neuromodulators — full drug profile →

Conditions studied

• Fibromyalgia (FM) — all drugs for Fibromyalgia (FM) →

Sponsor

Universidad Nacional Andres Bello

Who can join

Adults 18 to 65, female only, with Fibromyalgia (FM). Patients with the condition only — healthy volunteers not accepted.

What's being measured

Primary outcomes are the specific endpoints the trial is designed to prove or disprove.

• Changes of the numeric rating scale (0-10) for pain severity
  Time frame: Participants will be asked to rate their pain sensation at baseline, pre-intervention(T0) and immediately after the four-week intervention (T1).
  The primary outcome is the auto reported rating of pain severity with a numeric rating scale from 0 to 10 points. Commonly used to assess pain severity, where zero means "no pain" and 10 means "the worst pain imaginable". Participants will be asked to rate their pain sensation before and after the intervention.

Sponsor's own description

Exercise is recommended for people with fibromyalgia because it can reduce symptoms and improve quality of life. Some studies show that high-intensity exercises like running or cycling (also called high-intensity interval training, or HIIT) may reduce symptoms more effectively than slower, traditional exercises.

There are also new treatments, like non-invasive neuromodulation, which uses a gentle current to stimulate brain cells. This technique can help reduce pain in people with fibromyalgia. However, we don't yet know if combining HIIT and neuromodulation works better than exercise alone. We also want to find out if this combination helps improve other symptoms like fatigue and poor sleep.

The goal of this study is to see how a combination of HIIT and neuromodulation affects pain, fatigue, sleep, and muscle strength in women with fibromyalgia.

The investigators are asking two main questions:

Does combining HIIT and neuromodulation reduce pain better than exercise alone? Does this combination improve how the brain controls pain, muscles, and other symptoms like fatigue and sleep problems? What Will the Study Involve?

Three different exercise training programs will be compared:

HIIT with neuromodulation (tDCS): The participant will do HIIT by cycling at a high intensity for 1 minute, then resting for 2 minutes. Then, this will be repeated 10 times. At the same time, the researchers will place two small, damp sponges on the head of the participant. These sponges connect to the tDCS device, which sends a gentle current to your brain. It might feel a tingling sensation at first, but it will fade away.

HIIT with a "sham" (inactive) neuromodulation: This is similar to the first program, but the tDCS device will only be active for a few minutes at the beginning and end of the session.

HIIT alone: This involves just the cycling exercise with no brain stimulation. Who Can Participate?

The researchers are looking for women who:

Are 18-65 years old and have been diagnosed with fibromyalgia Experience moderate to high levels of pain Have stable blood pressure (if they have hypertension) Are not regularly active (don't do more than 30 minutes of exercise at least 3 times per week)

What Will the Study involve?

The participant will:

Attend 6 conditioning sessions (cycling) over two weeks to prepare their body. Complete 4 weeks of HIIT training, three times per week, at Universidad Andres Bello.

Attend 3 assessment sessions in our lab: before the conditioning, before the training, and after the training. These will include:

Non-invasive tests to measure your physical fitness, muscle strength, and pain sensitivity Brain and muscle connection tests. Questionnaires about your sleep, pain, fatigue, anxiety, depression, and exercise enjoyment

What the participant will get?

At the end of the study in addition to the training benefits, participants will receive a detailed report showing their body composition (muscle and fat levels) before and after the training.

Publications & conference data

No peer-reviewed publications indexed yet for this trial.