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.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
SINGLE
Enrollment
40
HIIT training: The participants will perform a HIIT protocol that consists of 1 minute of cycling at 50-60 revolutions per minute with a load that generates an effort of 80%-95% of their maximum Heart Rate (HR). Then 2 minutes of passive recovery, all this repeated 10 times (1x2x10). The effort of the session will be monitored by rating the perceived exertion (RPE) with a scale from 6-20 and HR. If the participant fails to recover within 2 minutes (\>70% maximum heart rate), resting time will be extended until an HR ≤ 70% of the maximum is achieved. The maximum HR of each session will be used for HIIT prescription for the next session.
Active tDCS: Two electrodes covered by a damp sponge will be placed on the scalp. The active electrode (anode) will be placed on the left motor cortex and the cathode on the contralateral supraorbital area before the exercise starts. The stimulation will start at the same time as the exercise, with an intensity of 2mA for 20 minutes.
Excercise and Rehabilitation Sciences Institute, Universidad Nacional Andres Bello
Santiago, Santiago Metropolitan, Chile
Changes of the numeric rating scale (0-10) for pain severity
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.
Time frame: Participants will be asked to rate their pain sensation at baseline, pre-intervention(T0) and immediately after the four-week intervention (T1).
Changes in generalised perception of fatigue
Generalised Fatigue: "is a profound and overwhelming, more severe, constant, and unpredictable than normal tiredness, not relieved by resting or sleep, not proportional to effort exerted, and disruptive in terms of motivation, activities, and cognition". The generalised fatigue will be assessed with: Multidimensional Fatigue Inventory (MFI). A questionnaire with 20 items divided into 5 domains: general fatigue, physical fatigue, mental fatigue, reduced activity and reduced motivation. The score range is between 4 to 20 points; a higher score indicates a greater degree of fatigue.
Time frame: Participants will be assessed at baseline, pre-intervention(T0) and immediately after the four-week intervention (T1).
Changes in generalised perception of fatigue
The Symptom Severity (SS) Score, a tool that measures the severity of symptoms like fatigue, unrefreshed sleep, and cognitive issues, along with other somatic symptoms, over the past week. Rating the severity from 0 (no problem) to 3 (severe).
Time frame: Participants will be assessed at baseline, pre-intervention(T0) and immediately after the four-week intervention (T1).
Changes in generalised perception of fatigue
Fibromyalgia Impact Questionnaire (FIQR): The sub-item evaluates fatigue with a rating scale of 11 blocks (0 to 10). Higher scores indicate no energy.
Time frame: Participants will be assessed at baseline, pre-intervention(T0) and immediately after the four-week intervention (T1).
Changes in sleep quality
The sleep quality will be measured with: Numeric Rating Scale (0-10): single-item tool that instructs the patient to describe the quality of sleep during the past 24 hours, where 0 is the best possible sleep and 10 is the worst possible sleep.
Time frame: Participants will be assessed at baseline, pre-intervention(T0) and immediately after the four-week intervention (T1).
Changes in sleep quality
The sleep quality will be measured with: Pittsburgh Sleep Quality Index (PSQI): a questionnaire that assesses duration, disturbance, latency, daytime dysfunction due to sleepiness, sleep efficiency, overall sleep quality and sleep medication use. Each component is scored from 0 to 3. Low scores indicate good sleep quality and high scores indicate poor sleep quality. (0-4: Good sleep quality; 5-10: Poor sleep quality; \>10: Very poor sleep quality).
Time frame: Participants will be assessed at baseline, pre-intervention(T0) and immediately after the four-week intervention (T1).
Changes in the level of depression
Depression will be assessed with two the subitem for depression of the "Fibromyalgia Impact Questionnaire (FIQR)". This goes from 0 to 10 in an 11-point rating scale with higher scores representing severity.
Time frame: Participants will be assessed at baseline, pre-intervention(T0) and immediately after the four-week intervention (T1).
Changes in the level of depression
Beck's Depression Inventory II (BDI-II): a 21-item self-reported measure that assesses the cognitive, affective, and neurovegetative symptoms of depression. The total score is 63 points. The range score is 0-13 "minimal", 14-19 "mild", 20-28 "moderate" and 29-63 "severe".
Time frame: Participants will be assessed at baseline, pre-intervention(T0) and immediately after the four-week intervention (T1).
Changes in quality of life
Quality of life will be assessed with the "Fibromyalgia Impact Questionnaire (FIQR)", which is a 21-item self-administered questionnaire. The questionnaire has 3 domains: function, overall impact and symptoms. The total score ranges from 0 to 100 points; higher scores indicate a severe impact.
Time frame: Participants will be assessed at baseline, pre-intervention(T0) and immediately after the four-week intervention (T1).
Changes in quality of life
Quality of life will be assessed with the "Short Form-36 (SF-36)". This questionnaire surveys health status, assesses physical functioning, role-physical, bodily pain, general health, vitality, social functioning, role-emotional and mental health. The highest score is 100, and the higher the score, the better the quality of life.
Time frame: Participants will be assessed at baseline, pre-intervention(T0) and immediately after the four-week intervention (T1).
Changes corticospinal excitability
To estimate corticospinal excitability peak-to-peak amplitude of the Motor Evoked Potential (MEP) will be measured. MEP is the response of the muscle to the stimulation of the corticomotor pathway with a magnetic stimulator and is measured with electromyography in milliAmpere (mA).
Time frame: Participants will be assessed at baseline, pre-intervention(T0) and immediately after the four-week intervention (T1).
Adherence to training
The adherence to exercise will be measured by the "Exercise Attitude Questionnaire". The score is 1 point "strongly disagree", 2 points "somewhat disagree", 3 points "somewhat agree", 4 points "strongly agree". The total score is 72 points, and the cut-off point for adherence is \>60 points
Time frame: Participants will be assessed at baseline, pre-intervention(T0) and immediately after the four-week intervention (T1).
Physical Activity
Physical Activity Readiness Questionnaire (PAR-Q): pre-participation screening tool for detection of possible health and cardiovascular problems. Include seven health-related questions to be answered yes or no. If the answer is "yes" to one question, the participant should talk to a physician before starting physical activity. If all questions are yes, the participant is fit to perform physical activity.
Time frame: Participants will be assessed at baseline, pre-intervention(T0) and immediately after the four-week intervention (T1).
Physical Activity
International Physical Activity Questionnaire (IPAQ): estimates the level of physical activity in different activity domains such as occupational, transport, yard/garden, household, leisure, and sitting. 27 items give a detailed picture of activity in different domains (work, transport, domestic, leisure). Measures frequency (days/week) and duration (minutes/day) of physical activity in the last 7 days, across intensity levels. It expresses activity in Metabolic Equivalent of Task (MET)-minutes per week (MET-min/week) or the energy cost of physical activities, where 1 MET is the energy expended at rest ≈ 3.5 mL O₂/kg/min. Higher values indicate greater physical activity level.
Time frame: Participants will be assessed at baseline, pre-intervention(T0) and immediately after the four-week intervention (T1).
Maximal voluntary isometric contraction
It is the maximal voluntary effort of isometric contraction. The strength of the quadriceps will be evaluated during 3 trials using an isokinetic dynamometer (Isoforce®).
Time frame: Participants will be assessed at baseline, pre-intervention(T0) and immediately after the four-week intervention (T1).
Muscle endurance
A knee extension at 20% maximal voluntary contraction will be performed until exhaustion. Participants' perception of effort will be measured using the 15-point rating of perceived exertion (RPE) scale every 20 seconds of the time to exhaustion task.
Time frame: Participants will be assessed at baseline, pre-intervention(T0) and immediately after the four-week intervention (T1).
Aerobic capacity
The aerobic capacity will be measured during an incremental cycling test. During this test, will be determined the maximum oxygen consumption (VO2peak) and the production of maximum concentric power (POmax)
Time frame: Participants will be assessed at baseline, pre-intervention(T0) and immediately after the four-week intervention (T1).
Pain Sensitivity
Pressure will be applied at an increasing rate of 50 kPa per second with an algometer placed perpendicular over the skin until the sensation of pressure changes to pain also known as pain pressure threshold (PPT).
Time frame: Participants will be asked to rate their pain sensation at baseline, pre-intervention(T0) and immediately after the four-week intervention (T1).
Muscle soreness
To quantify the muscle soreness, the participants must mark with a straight vertical line on the horizontal line (from 0 to 100 millimetres), after performing a task of sitting and standing 3 times.
Time frame: Participants will be asked to rate their pain sensation at baseline, pre-intervention(T0) and immediately after the four-week intervention (T1).
Changes in the number of painful areas in the body
The participant will report the number of painful areas of the body (upper, lower, or axial regions) over the last week. The total score is 19, where 1 region pain equals 1 point, divided by the left upper region, right upper region, axial region, left lower region and right lower region.
Time frame: Participants will be assessed at baseline, pre-intervention(T0) and immediately after the four-week intervention (T1).
Changes in Active Motor Threshold
It is the lowest stimulus intensity of a transcranial magnetic stimulator to generate a motor evoked potential with a peak-to-peak amplitude of 200 microvolts in at least five out of 10 consecutive trials when the muscle is activated at 20% of the maximal voluntary contraction.
Time frame: Participants will be assessed before (T0) and after (T1) the four-week intervention.
Changes in Resting Motor Threshold
It is the lowest stimulus intensity of a transcranial magnetic stimulator to generate a motor evoked potential with a peak-to-peak amplitude of 50 microvolts in at least five out of 10 consecutive trials when the muscle is at rest.
Time frame: Participants will be assessed at baseline, pre-intervention(T0) and immediately after the four-week intervention (T1).
Changes in the silence period after the motor evoked potential
It is the temporary interruption of the electromyographic signal from a muscle following a motor evoked potential. It is considered a measure of the excitability mediated by gamma-aminobutyric acid receptors. It will be measured in milliseconds (ms) from the end of the motor evoked potential wave to the recovery of the signal to the basal averaged amplitude.
Time frame: Participants will be assessed at baseline, pre-intervention(T0) and immediately after the four-week intervention (T1).
Changes in anxiety levels
Changes in anxiety will be assessed with the subitem that evaluates anxiety of the "Fibromyalgia Impact Questionnaire (FIQR)" with 11 blocks (0 to 10), where higher scores indicate a severe impact.
Time frame: Participants will be assessed at baseline, pre-intervention(T0) and immediately after the four-week intervention (T1).
Changes in anxiety levels
State Trait Anxiety Inventory (STAI) will be used to assess anxiety levels. The total score is 80 points. The score is classified as 20-37 "no or low anxiety", 38-44 "moderate anxiety" and 45-80 "high anxiety".
Time frame: Participants will be assessed at baseline, pre-intervention(T0) and immediately after the four-week intervention (T1).
Level of enjoyment of exercise
The enjoyment of exercise will be assessed with the "Physical Activity Enjoyment Scale". This scale includes 16 items with a maximum score of 80 points. The rating scale ranges from 1 ("dislike a lot") to 5 ("enjoy a lot").
Time frame: Participants will be assessed at baseline, pre-intervention(T0) and immediately after the four-week intervention (T1).
Level of muscle soreness
The participants will be asked to sit and stand 3 times with their legs shoulder-width apart and bend their knees to 90°. The volunteer must rate the level of discomfort by marking a straight vertical line on the horizontal line of a 100 mm rating scale. Higher values indicate greater soreness.
Time frame: Participants will be assessed at baseline, pre-intervention(T0) and immediately after the four-week intervention (T1).
Level of fear of movement
The fear of movement will be assessed with the Tampa Scale for Kinesiophobia. A questionnaire of 17 questions, with a maximum of 68 points. Scores \> 37 points indicate high levels of kinesiophobia, and ˂ 37 points indicate low levels.
Time frame: Participants will be assessed at baseline, pre-intervention(T0) and immediately after the four-week intervention (T1).
Changes in negative cognitions related to pain
The catastrophization of pain will be assessed with a self-reported questionnaire designed to assess catastrophic thinking related to pain among adults. This "Pain Catastrophizing Scale" has 13 items, each describing a thought or feeling about pain. Each item is rated on a 5-point Likert scale from 0 to 4, with a maximal score of 52. Higher scores indicate high catastrophising.
Time frame: Participants will be assessed at baseline, pre-intervention(T0) and immediately after the four-week intervention (T1).
Changes in negative cognitions related to pain
The acceptance of chronic Pain will be assessed with a 20-item questionnaire, "Chronic Pain Acceptance Questionnaire for Fibromyalgia", scored with a 7-point Likert scale (0 = "never true" to 6 = "always true"). Higher scores indicate better adjustment and functioning.
Time frame: Participants will be assessed at baseline, pre-intervention(T0) and immediately after the four-week intervention (T1).
Changes in body composition
The weight and body composition in percentage of muscle, fat and water will be measured with a bioimpedanciometer (InBody 770).
Time frame: Participants will be assessed at baseline, pre-intervention(T0) and immediately after the four-week intervention (T1).
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.