An interventional study of Slow Breathing with Visual Pacer and Slow Breathing without Visual Pacer in Fibromyalgia and Fibromyalgia Syndrome, sponsored by University of Malaga. Enrolling by invitation at 2 sites in Spain. Open to female participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-02-11.
Sponsored by University of Malaga · Not applicable, Interventional, and Basic science
This randomized controlled trial investigates whether slow breathing techniques influence heart rate variability, exercise self-efficacy, and resistance exercise performance in women with fibromyalgia. Participants will be randomly assigned to one of three breathing conditions (slow breathing with visual pacer, slow breathing without pacer, or spontaneous breathing) before performing a biceps curl resistance exercise. The study will examine how breathing patterns interact with psychological variables (anxiety sensitivity, pain catastrophizing, pain hypervigilance, and kinesiophobia) to affect physiological and performance outcomes.
Background: Fibromyalgia is considered one of the most representative central sensitivity syndromes, where central sensitization is the predominant characteristic. Resistance and strength training have demonstrated efficacy as therapeutic strategies for fibromyalgia patients. Slow breathing has been shown to reduce anxiety, perceived stress, and pain intensity while increasing heart rate variability (HRV), a biomarker of stress reactivity. The Fear-Avoidance Model of Pain demonstrates that anxiety sensitivity, pain catastrophizing, hypervigilance, and fear of pain/movement largely determine activity levels in chronic pain patients. However, no studies have examined how slow breathing interacts with these psychological variables to enhance resistance exercise performance in fibromyalgia patients.
Study Design: Single-session, three-arm randomized controlled trial with parallel group assignment.
Experimental Procedure:
Phase 1 - Baseline Assessment:
Phase 2 - Resistance Exercise Preparation:
Phase 3 - Breathing Intervention (8 minutes): Participants randomly assigned to:
Phase 4 - Resistance Exercise Test:
Phase 5 - Post-Exercise Assessment:
Safety Monitoring: Continuous observation by trained evaluators; clear stopping criteria.
1,243 studies on the registry are indexed under Fibromyalgia; 256 are open to participants now.
This study's planned enrollment of 159 is above the median of 60 across 937 interventional studies indexed under Fibromyalgia.
Browse Fibromyalgia studies →University of Malaga is the lead sponsor of 121 studies on the registry; 34 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants perform 8 minutes of paced slow breathing (6 breaths/min) with continuous visual guidance before resistance exercise test.
Behavioral: Slow Breathing with Visual Pacer
Participants perform 8 minutes of self-paced slow breathing (6 breaths/min target) after brief training, without continuous visual guidance, before resistance exercise test.
Behavioral: Slow Breathing without Visual Pacer
Participants breathe naturally at their spontaneous rate for equivalent duration before resistance exercise test.
Behavioral: Spontaneous Breathing (Active Control)
Participants receive brief training using a visual pacer displayed on computer screen showing a line that rises during inhalation and falls during exhalation. The pacing is set to 6 respiratory cycles per minute (4 seconds inhalation, 6 seconds exhalation). Participants place one hand below chest and abdomen to monitor diaphragmatic movement. After training, participants continue slow breathing with the visual pacer continuously displayed, maintaining the prescribed respiratory rate.
Participants receive identical brief training using the visual pacer to learn the slow breathing pattern (6 cycles per minute: 4 seconds inhalation, 6 seconds exhalation). Hand placement below chest and abdomen to monitor diaphragmatic movement. After training, the visual pacer is removed and participants attempt to maintain the slow breathing pattern independently without external guidance.
Participants spend equivalent time breathing at their natural, spontaneous rate. They receive similar attention from evaluators but no specific breathing instructions. Participants are instructed to breathe normally at their usual pace and rhythm.
Heart Rate Variability (HRV) - Change from Baseline
Root mean square of successive differences (RMSSD) in milliseconds
Time frame: Measured: 5 min baseline, 8 min during breathing intervention, and 5 min post-exercise recovery.
Number of Biceps Curl Repetitions
Number of properly executed biceps curl repetitions at 50% estimated 1-RM performed to voluntary exhaustion with proper form maintained.
Time frame: Immediately during the resistance exercise test (single session).
Exercise-Related Self-Efficacy
Single-item 0-10 numeric rating scale.
Time frame: Immediately post-exercise.
Fatigue
Borg Rating Of Perceived Exertion. Rating of perceived exertion is an outcome measure scale used to gauge one's exercise intensity without the need to rely on physiological parameters. The scale rates exertion from a scale of 6 (no exertion) to 20 (maximum effort).
Time frame: Immediately post-exercise
Change in Current Pain Intensity
Numeric Rating Scale (NRS) 0-10
Time frame: Immediately post-exercise
Change in Anxiety
Numeric Rating Scale (NRS) 0-10
Time frame: Immediately post-exercise.
Perceived effort required to do the biceps exercise
Numeric Rating Scale (NRS) 0-10.
Time frame: Immediately post-exercise
Breathing Difficulty
Numeric Rating Scale (NRS) 0-10
Time frame: Immediately after breathing intervention.
Plan to share: Yes — We will share the joint database through a web link for public access.
Start is estimated for Feb 2026; primary completion for Apr 2026, 2 months later.
Of 436 non-industry interventional studies with no phase under Fibromyalgia, half reached primary completion within 16 months of starting (the median), counting those still running; a quarter within 6 and three quarters within 31. This study's planned 2 months is below that.
Counting every sponsor, half of 449 studies reached it within 15 months; a quarter within 6 and three quarters within 31.
How these figures are worked out, and which studies are left out of them.
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