Fibromyalgia is a chronic syndrome characterized by widespread musculoskeletal pain, fatigue, sleep disturbances, and functional impairment, which significantly affects quality of life. Physical exercise is considered one of the most effective non-pharmacological interventions for the management of this condition; however, uncertainty remains regarding the most appropriate type, intensity, and frequency of exercise for different patient profiles. The aim of this study is to analyze the effects of a microdoses isokinetic exercise program on physical condition, perceived pain, inflammatory profile and quality of life in women diagnosed with fibromyalgia.
Physical exercise is one of the non-pharmacological treatments with the strongest evidence and effectiveness in the management of fibromyalgia, as it has been shown to improve muscle strength and, consequently, patients' quality of life. One of the main limitations in this population is low adherence to traditional exercise programs due to chronic pain. Microdoses exercise training emerges as an alternative approach, based on the principle of the minimum effective dose. To implement this intervention, the training program will be conducted using isokinetic exercise, which allows precise control of movement velocity and joint position to ensure safe conditions. Accordingly, the aim of the present study is to evaluate the effects of an isokinetic exercise microdosing program in women with fibromyalgia over an 8-week intervention period.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
SUPPORTIVE_CARE
Masking
NONE
Enrollment
36
Participants assigned to the experimental group will perform the sessions under supervision. Each session will begin with a warm-up consisting of joint mobility exercises and 5 minutes of low-intensity cycling. This will be followed by the main exercise component, which will consist of one set of five repetitions of knee extension exercise. During the initial sessions, the exercise will be performed at 60°/s, with a gradual and controlled progression up to a maximum of eight repetitions. To finish, participants will complete 5 minutes of stretching and controlled breathing.
Miguel de Cervantes European University
Valladolid, Valladolid, Spain
RECRUITINGPeak torque
The change in the peak torque (in Nm) will be assessed in the concentric part of a knee extension exercise (1x5) at 60º/s using the Biodex System 4.
Time frame: Baseline, up to study completion (8 weeks); week 9
Peak torque
The change in the peak torque (in Nm) will be assessed in the eccentric part of a knee extension exercise (1x5) at 60º/s using the Biodex System 4.
Time frame: Baseline, up to study completion (8 weeks); week 9
Agonist-antagonist ratio
The change in the agonist-antagonist ratio (%) of the knee extension exercise will be assessed using the Biodex System 4.
Time frame: Baseline, up to study completion (8 weeks); week 9
Total work
The change in the total work (in J) of the knee extension exercise will be assessed using the Biodex System 4.
Time frame: Baseline, up to study completion (8 weeks); week 9.
Height
The change in the height will be assessed by centimeters (cm).
Time frame: Baseline, week 9
Muscle electrical activity (amplitude)
The MuscleLab system with electromyography will be used to measure muscle electrical activity in vastus lateralis (in microvolts) recording during exercise, following the standard recommendations for electrode placement and with signal normalization.
Time frame: Baseline, week 9
Muscle electrical activity (frequency)
The MuscleLab system with electromyography will be used to measure muscle electrical activity in vastus lateralis (in Hz) recording during exercise, following the standard recommendations for electrode placement and with signal normalization.
Time frame: Baseline, week 9
Muscle electrical activity (amplitude)
The MuscleLab system with electromyography will be used to measure muscle electrical activity in rectus femoris (in microvolts) recording during exercise, following the standard recommendations for electrode placement and with signal normalization.
Time frame: Baseline, week 9
Muscle electrical activity (frequency)
The MuscleLab system with electromyography will be used to measure muscle electrical activity in in rectus femoris bilateral (in Hz) recording during exercise, following the standard recommendations for electrode placement and with signal normalization.
Time frame: Baseline, week 9
Weight
The change in the weight will be assessed by kilograms (kg).
Time frame: Baseline, week 9
Body composition (Bioimpedance)
The change in body composition (%) will be assessed using the NUTRILAB bioimpedance device (AKERN Srl, Florence, Italy). Users will be instructed to remove all metal-containing objects and remain in a supine position on a couch during the measurements, with the legs in 45° abduction, the shoulders in 30° abduction relative to the center of the body and the hands in pronation. After cleaning the skin with alcohol, two adhesive electrodes (Biatrodes Akern Srl, Florence, Italy) will be placed on the surface of the right hand and two on the right foot. The measurement results will be given in different unit measures depending on the specific variable assessed.
Time frame: Baseline, week 9.
Muscle thickness
The change in the muscle thickness (in centimeters) of the vastus lateralis will be measured using a real-time B-mode ultrasound device with a linear transducer. A water-soluble, hypoallergenic transmission gel will be applied to the probe, to serve as a conductive interface between the probe and the participant's skin.
Time frame: Baseline, week 9.
Muscle thickness
The change in the muscle thickness (in centimeters) of the rectus femoris bilateral will be measured using a real-time B-mode ultrasound device with a linear transducer. A water-soluble, hypoallergenic transmission gel will be applied to the probe, to serve as a conductive interface between the probe and the participant's skin.
Time frame: Baseline, week 9.
Pain score
The change in the score of pain will be assessed through a Numeric Rating Scale (NRS), numbered from 0 "no pain at all" to 10 "worst pain imaginable."
Time frame: Baseline, up to study completion (8 weeks); week 9.
Pain location
The pain location will be assessed using a body chart. The participant will identify using a graphical representation of the body the location of the pain, without indicating its intensity.
Time frame: Baseline, up to study completion (8 weeks); week 9.
Quality of life: Short Form 36 Health Survey
The change in quality-of-life scores will be assessed using the Short Form 36 Health Survey (SF-36). This instrument consists of 36 items, organized into eight health domains, with a score ranging from 0 to 100.
Time frame: Baseline, week 9.
Quality of life: EuroQOL five dimensions questionnaire
The change in quality-of-life scores will be assessed using the EuroQOL five-dimensions questionnaire (EQ-5D). This instrument consists of five dimensions and a visual analogue scale (VAS).The response types involve a Likert scale (1-5 for dimensions), multiple-choice (selecting the level), and a rating scale (0-100 for VAS).
Time frame: Baseline, week 9.
Sleep quality
The change in sleep quality scores will be assessed using the Pittsburgh Sleep Quality Index (PSQI). This index consists of 19 self-rated items, which are grouped into seven component scores, ranging from 0 to 21.
Time frame: Baseline, week 9.
Physical activity levels
The levels of physical activity will be recorded using the International Physical Activity Questionnaire (score) a standardized tool that defines and measures physical activity based on frequency (days) and duration (minutes) over a week. It categorizes physical activity into vigorous-intensity, moderate-intensity, and walking, and also assesses time spent sitting.
Time frame: Baseline, week 9.
Heart rate variability
The change in heart rate variability (HRV) will be measured in milliseconds (ms) to assess autonomic nervous system function. Participants will use a Polar H10 heart rate monitor (Polar Electro Oy, Kempele, Finland) with the Elite HRV app for 15 minutes.
Time frame: Baseline, week 9.
Interleukin-6 (IL-6) levels
The change in the plasma concentration of interleukin-6 (mg/l and/or ng/ml) will be assessed. Venous blood samples will be collected. The plasma concentrations will be analyzed using an enzyme-linked immunosorbent assay (ELISA).
Time frame: Baseline, week 9.
Tumor necrosis factor-alpha (TNF-α) levels
The change in the plasma concentration of tumor necrosis factor-alpha (mg/l and/or ng/ml) will be assessed. Venous blood samples will be collected. The plasma concentrations will be analyzed using an enzyme-linked immunosorbent assay (ELISA).
Time frame: Baseline, week 9.
C-reactive protein (CRP) levels
The change in the plasma concentration of C-reactive protein (mg/l and/or ng/ml) will be assessed. Venous blood samples will be collected. The plasma concentrations will be analyzed using an enzyme-linked immunosorbent assay (ELISA).
Time frame: Baseline, week 9.
Cortisol
Cortisol The change in the plasma concentration of cortisol (mg/l and/or ng/ml) will be assessed. Venous blood samples will be collected. The plasma concentrations will be analyzed using an enzyme-linked immunosorbent assay (ELISA).
Time frame: Baseline, week 9.
Glucose
The change in the plasma concentration of glucose (mg/l and/or ng/ml) will be assessed. Venous blood samples will be collected. The plasma concentrations will be analyzed using an enzyme-linked immunosorbent assay (ELISA).
Time frame: Baseline, week 9.
Testosterone (total)
The change in the plasma concentration of total testosterone (mg/l and/or ng/ml) will be assessed. Venous blood samples will be collected. The plasma concentrations will be analyzed using an enzyme-linked immunosorbent assay (ELISA).
Time frame: Baseline, week 9.
Testosterone (free)
The change in the plasma concentration of free testosterone (mg/l and/or ng/ml) will be assessed. Venous blood samples will be collected. The plasma concentrations will be analyzed using an enzyme-linked immunosorbent assay (ELISA).
Time frame: Baseline, week 9.
Sex hormone-binding globulin
The change in the plasma concentration of sex hormone-blinding globulin (mg/l and/or ng/ml) will be assessed. Venous blood samples will be collected. The plasma concentrations will be analyzed using an enzyme-linked immunosorbent assay (ELISA).
Time frame: Baseline, week 9.
Dehydroepiandrosterone sulfate
The change in the plasma concentration of dehydroepiandrosterone sulfate (mg/l and/or ng/ml) will be assessed. Venous blood samples will be collected. The plasma concentrations will be analyzed using an enzyme-linked immunosorbent assay (ELISA).
Time frame: Baseline, week 9.
Fibromyalgia Impact Questionnaire
The change in the score of the fibromyalgia impact will be assessed using the fibromyalgia impact questionnaire (FIQ), a 10-item questionnaire that covers Physical Function, Work Status, and Symptoms. The total score ranges from 0 to 100, a higher score (closer to 100) indicates a greater impact of fibromyalgia, signifying higher functional disability, more severe symptoms, and a worse quality of life. Conversely, a lower score (closer to 0) indicates a better health status.
Time frame: Baseline, week 9.
Nutritional intake: Consume frequency
The change in the dietary intake (consume frequency) will be assessed with a Food Frequency Questionnaire (FFQ). This tool measures how often foods and food groups are consumed over a specific period, enabling the estimation of typical dietary patterns. The total days per week that a participant consumes a type of food will be recorded.
Time frame: Baseline, week 9.
Nutritional intake: 24-hour register
The change in the dietary intake will be assessed with a 24-hour dietary recall . This tool measures how often foods and food groups are consumed over a specific period, enabling the estimation of typical dietary patterns.
Time frame: Baseline, week 9.
Canadian Occupational Performance Measure
The change in the occupational performance score will we assessed using the Canadian Occupational Performance Measure (COPM). The participant will identify their priorities for activities in daily living. After priorities are identified, each is rated for current performance and satisfaction with current performance on a scale of 1 (not able to do it / not satisfied at all) to 10 (able to do it extremely well / extremely satisfied).
Time frame: Baseline, week 9.
Goal Attainment Scaling
The change in the goal achievement progress will be assessed using Goal Attainment Scaling, a standardized individualized outcome measure in which five measurable outcomes are specified for each goal. The total score will range from -2 to 2.
Time frame: Baseline, week 9.
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.