Effects of a Isokinetic Exercise in Women With Fibromyalgia (FibrodEx)

Effects of a Microdoses Isokinetic Exercise Protocol in Women With Fibromyalgia

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.

Study Overview

• Status: Recruiting
• Conditions: Fibromyalgia (FM)
• Intervention / Treatment: Other: Exercise

Detailed Description

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
• Enrollment (Estimated): 36
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Alejandro Santos Lozano, PhD; Phone Number: 22292 0034983001000; Email: asantos@uemc.es
• Study Contact Backup: Name: Sergio Maroto Izquierdo, PhD; Phone Number: 22292 0034983001000; Email: smaroto@uemc.es

Study Locations

• Spain
  • Valladolid
    • Valladolid, Valladolid, Spain, 47012
      • Recruiting
      • Miguel de Cervantes European University
      • Sub-Investigator: María Merino País, MSc
      • Sub-Investigator: Francisco Javier Iruzubieta Barragán, PhD
      • Sub-Investigator: Paula Crespo Escobar, PhD
      • Sub-Investigator: Susana López Ortiz, PhD
      • Sub-Investigator: Sergio Maroto Izquierdo, PhD
      • Sub-Investigator: Celia García Chico, PhD
      • Contact: Alejandro Santos Lozano, PhD; Phone Number: 22292 0034983001000; Email: asantos@uemc.es
      • Contact: Francisco Javier Gutiérrez Pecharromán, PhD; Phone Number: 22293 0034983001000; Email: fjgutierrez@uemc.es
      • Sub-Investigator: Olga Isabel Fernández Rodríguez, PhD
      • Sub-Investigator: Paula Redondo Delgado, MSc
      • Sub-Investigator: Irati Jauregui Fajardo, MSc
      • Sub-Investigator: Kayvan Khoramipour, PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Women aged ≥ 18 years diagnosed with fibromyalgia according to current clinical criteria.
• Clinical and pharmacological stability during the weeks prior to participation in the study.
• Ability to perform supervised exercise and to complete the assessments.
• Written informed consent.

Exclusion Criteria:

• Cardiovascular, neurologic, musculoskeletal or systemic pathology that contraindicate the performance of exercise.
• Significant change in pharmacological treatment during the period immediately preceding the study.
• Any condition that, in clinical judgement, prevents them from following the protocol safely.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Supportive Care
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Exercise; An isokinetic exercise program of microdosing will be conducted over 8 weeks, with a frequency of three sessions per week, each lasting 20-25 minutes. Participants will also receive information on healthy lifestyle habits.	Other: Exercise; 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.
No Intervention: Control group; Participants assigned to the control group will continue with their usual treatment and will receive general recommendations for healthy lifestyle.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Peak 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.	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.	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.	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.	Baseline, up to study completion (8 weeks); week 9.
Height	The change in the height will be assessed by centimeters (cm).	Baseline, week 9

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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.	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.	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.	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.	Baseline, week 9
Weight	The change in the weight will be assessed by kilograms (kg).	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.	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.	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.	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."	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.	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.	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).	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.	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.	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.	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).	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).	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).	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).	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).	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).	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).	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).	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).	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.	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.	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.	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).	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.	Baseline, week 9.

Collaborators and Investigators

• Sponsor: European University Miguel de Cervantes
• Investigators: Principal Investigator: Alejandro Santos Lozano, PhD, Miguel de Cervantes European University

Publications and helpful links

General Publications

• Larsson A, Palstam A, Lofgren M, Ernberg M, Bjersing J, Bileviciute-Ljungar I, Gerdle B, Kosek E, Mannerkorpi K. Resistance exercise improves muscle strength, health status and pain intensity in fibromyalgia--a randomized controlled trial. Arthritis Res Ther. 2015 Jun 18;17(1):161. doi: 10.1186/s13075-015-0679-1.
• Sosa-Reina MD, Nunez-Nagy S, Gallego-Izquierdo T, Pecos-Martin D, Monserrat J, Alvarez-Mon M. Effectiveness of Therapeutic Exercise in Fibromyalgia Syndrome: A Systematic Review and Meta-Analysis of Randomized Clinical Trials. Biomed Res Int. 2017;2017:2356346. doi: 10.1155/2017/2356346. Epub 2017 Sep 20.
• Afonso J, Nakamura FY, Baptista I, Rendeiro-Pinho G, Brito J, Figueiredo P. Microdosing: Old Wine in a New Bottle? Current State of Affairs and Future Avenues. Int J Sports Physiol Perform. 2022 Oct 6;17(11):1649-1652. doi: 10.1123/ijspp.2022-0291. Print 2022 Nov 1.
• Couto N, Monteiro D, Cid L, Bento T. Effect of different types of exercise in adult subjects with fibromyalgia: a systematic review and meta-analysis of randomised clinical trials. Sci Rep. 2022 Jun 20;12(1):10391. doi: 10.1038/s41598-022-14213-x.
• Tavares LF, Germano Maciel D, Pereira Barros da Silva TY, Brito Vieira WH. Comparison of functional and isokinetic performance between healthy women and women with fibromyalgia. J Bodyw Mov Ther. 2020 Jan;24(1):248-252. doi: 10.1016/j.jbmt.2019.05.024. Epub 2019 May 23.
• Voss AC, Chambers TL, Gries KJ, Jemiolo B, Raue U, Minchev K, Begue G, Lee GA, Trappe TA, Trappe SW. Exercise microdosing for skeletal muscle health applications to spaceflight. J Appl Physiol (1985). 2024 May 1;136(5):1040-1052. doi: 10.1152/japplphysiol.00491.2023. Epub 2024 Jan 11.
• Albuquerque MLL, Monteiro D, Marinho DA, Vilarino GT, Andrade A, Neiva HP. Effects of different protocols of physical exercise on fibromyalgia syndrome treatment: systematic review and meta-analysis of randomized controlled trials. Rheumatol Int. 2022 Nov;42(11):1893-1908. doi: 10.1007/s00296-022-05140-1. Epub 2022 May 23.
• Estevez-Lopez F, Maestre-Cascales C, Russell D, Alvarez-Gallardo IC, Rodriguez-Ayllon M, Hughes CM, Davison GW, Sanudo B, McVeigh JG. Effectiveness of Exercise on Fatigue and Sleep Quality in Fibromyalgia: A Systematic Review and Meta-analysis of Randomized Trials. Arch Phys Med Rehabil. 2021 Apr;102(4):752-761. doi: 10.1016/j.apmr.2020.06.019. Epub 2020 Jul 25.

Study record dates

Study Major Dates

• Study Start (Estimated): April 1, 2026
• Primary Completion (Estimated): July 1, 2026
• Study Completion (Estimated): July 1, 2026

Study Registration Dates

• First Submitted: March 11, 2026
• First Submitted That Met QC Criteria: March 16, 2026
• First Posted (Actual): March 19, 2026

Study Record Updates

• Last Update Posted (Actual): April 16, 2026
• Last Update Submitted That Met QC Criteria: April 13, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: Exercise; Pain; Fibromyalgia; Microdosing; Isokinetic; Non-Pharmacological treatment
• Additional Relevant MeSH Terms: Neurologic Manifestations; Musculoskeletal Diseases; Nervous System Diseases; Muscular Diseases; Neuromuscular Diseases; Rheumatic Diseases; Pathological Conditions, Signs and Symptoms; Behavior; Signs and Symptoms; Pain; Fibromyalgia; Motor Activity; Motor Activity; Movement; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena; Exercise
• Other Study ID Numbers: PI-DOC012-FibrodEx

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No