An interventional study of Inspiratory Muscle Training and Diaphragmatic Breathing Exercises in Generalized Anxiety Disorder (GAD), sponsored by Saglik Bilimleri Universitesi. Recruiting at 1 site in Turkey (Türkiye). Open to participants aged 18 Years to 65 Years. Per ClinicalTrials.gov, last updated 2026-11-03.
Sponsored by Saglik Bilimleri Universitesi · Not applicable, Interventional, and Supportive care
This study will compare inspiratory muscle training and diaphragmatic breathing exercises in individuals with generalized anxiety disorder (GAD). It aims to investigate whether adding either breathing-based intervention to a combined exercise program improves anxiety symptoms and other health-related outcomes compared with adding progressive muscle relaxation.
Participants will be randomly assigned to one of three groups. All groups will receive the same combined exercise program. In addition, the first group will perform inspiratory muscle training, which involves breathing against resistance to strengthen the inspiratory muscles. The second group will perform diaphragmatic breathing exercises, which focus on using the diaphragm during breathing. The third group will receive Jacobson's progressive muscle relaxation technique, which involves systematically tensing and relaxing different muscle groups. All interventions will be delivered over eight weeks using a hybrid telerehabilitation approach combining face-to-face, synchronous online, and independent home-based sessions.
The study will evaluate anxiety symptoms, respiratory muscle strength, pulmonary function, functional exercise capacity, dyspnea, quality of life, depression symptoms, and heart rate variability. The findings may provide further evidence on the comparative effects of these interventions when added to a combined exercise program in individuals with GAD.
Generalized anxiety disorder (GAD) is characterized by persistent and excessive anxiety that may adversely affect individuals' daily functioning and quality of life. Although pharmacological and psychological treatments are commonly used, complementary approaches targeting respiratory function and physical activity may provide additional benefits.
This three-arm, parallel-group randomized controlled trial will compare inspiratory muscle training (IMT) and diaphragmatic breathing exercises with Jacobson's progressive muscle relaxation (PMR) in individuals with GAD. The study is designed to investigate the effects of these interventions when added to a standardized combined exercise program.
All participants will follow the same eight-week combined aerobic and resistance exercise program, consisting of three sessions per week. In addition, participants will be allocated to one of three intervention groups:
Group 1 - Inspiratory Muscle Training: Participants will perform IMT using a threshold-based inspiratory muscle training device. The training load will be adjusted progressively throughout the intervention period.
Group 2 - Diaphragmatic Breathing Exercises: Participants will perform structured diaphragmatic breathing exercises focusing on controlled breathing and diaphragmatic activation.
Group 3 - Active Control: Participants will perform Jacobson's progressive muscle relaxation technique, involving systematic contraction and relaxation of different muscle groups.
The interventions will be delivered using a hybrid telerehabilitation model consisting of one face-to-face session, one synchronous online session, and one independent home-based session per week. This approach will provide a combination of supervised and home-based intervention sessions while maintaining comparable therapist contact across groups.
All clinical and physiological assessments will be conducted face-to-face at baseline and following completion of the eight-week intervention.
The study aims to contribute to the evidence regarding respiratory-based physiotherapy interventions in GAD and to explore the feasibility of integrating these approaches into hybrid telerehabilitation programs.
151 studies on the registry are indexed under Generalized Anxiety Disorder; 89 are open to participants now.
This study's planned enrollment of 51 is below the median of 98 across 124 interventional studies indexed under Generalized Anxiety Disorder.
Browse Generalized Anxiety Disorder studies →Saglik Bilimleri Universitesi is the lead sponsor of 452 studies on the registry; 141 are open to participants now.
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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.
Diagnosis of generalized anxiety disorder (GAD) by a psychiatrist according to DSM-5 criteria.
A score of 10 or higher on the Generalized Anxiety Disorder-7 (GAD-7) scale. Receiving clinically stable pharmacological treatment. Aged 18-65 years. No condition that prevents the use of a smartphone or access to the internet.
Exclusion Criteria:
Severe pulmonary diseases (e.g., chronic obstructive pulmonary disease [COPD] or an asthma attack) or cardiac diseases (e.g., unstable angina).
A primary psychiatric diagnosis other than generalized anxiety disorder. Orthopedic or neurological limitations that prevent exercise. Severe cardiovascular disease. Pregnancy. Substance use disorder. Recent abdominal or thoracic surgery.
Participants in this group will receive inspiratory muscle training in addition to the common combined exercise program.
Device: Inspiratory Muscle Training
Participants in this group will perform diaphragmatic breathing exercises in addition to the common combined exercise program.
Behavioral: Diaphragmatic Breathing Exercises
Participants in this group will perform progressive muscle relaxation in addition to the common combined exercise program.
Behavioral: Progressive Muscle Relaxation
Inspiratory muscle training will be performed using a pressure-threshold device. Training will begin at 30% of maximum inspiratory pressure, with the load increased by 5% per week. Each session will consist of two sets of 30 inspiratory efforts.
Participants will perform structured diaphragmatic breathing exercises according to the study protocol.
Participants will perform progressive muscle relaxation according to the study protocol.
Change in Anxiety Severity Measured by the GAD-7
Anxiety severity will be assessed using the Generalized Anxiety Disorder-7 (GAD-7), a 7-item self-report questionnaire assessing anxiety symptoms over the previous two weeks. Total scores range from 0 to 21, with higher scores indicating greater anxiety severity. The change in total score from baseline to the end of the intervention will be evaluated.
Time frame: Baseline (week 1) and at the end of the intervention (week 8).
Change in Forced Vital Capacity (FVC)
Pulmonary function will be assessed using spirometry. Forced vital capacity (FVC), representing the maximum volume of air that can be forcibly exhaled after a full inspiration, will be measured in liters (L).
Time frame: Baseline (week 1) and at the end of the intervention (week 8).
Change in Forced Expiratory Volume in One Second (FEV1)
Pulmonary function will be assessed using spirometry. Forced expiratory volume in one second (FEV1), representing the volume of air forcibly exhaled during the first second, will be measured in liters (L).
Time frame: Baseline (week 1) and at the end of the intervention (week 8).
Change in FEV1/FVC Ratio
The FEV1/FVC ratio will be calculated by dividing forced expiratory volume in one second (FEV1) by forced vital capacity (FVC) and will be expressed as a percentage (%).
Time frame: Baseline (week 1) and at the end of the intervention (week 8).
Change in Peak Expiratory Flow (PEF)
Peak expiratory flow (PEF) will be assessed using spirometry and expressed in liters per second (L/s).
Time frame: Baseline (week 1) and at the end of the intervention (week 8).
Change in Respiratory Muscle Strength
Respiratory muscle strength will be assessed by measuring maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP).
Time frame: Baseline (week 1) and at the end of the intervention (week 8).
Change in Functional Exercise Capacity
Functional exercise capacity will be assessed using the Six-Minute Walk Test (6MWT). The total distance walked will be recorded in meters.
Time frame: Baseline (week 1) and at the end of the intervention (week 8).
Change in Sleep Quality
Sleep quality will be assessed using the Pittsburgh Sleep Quality Index (PSQI). Total scores range from 0 to 21, with higher scores indicating poorer sleep quality.
Time frame: Baseline (week 1) and at the end of the intervention (week 8).
Change in Health-Related Quality of Life
Health-related quality of life will be assessed using the 36-Item Short Form Health Survey (SF-36), which evaluates eight health dimensions. Scores range from 0 to 100, with higher scores indicating better health status.
Time frame: Baseline (week 1) and at the end of the intervention (week 8).
Change in Perceived Dyspnea
Perceived dyspnea will be assessed using the Modified Borg Dyspnea Scale, which ranges from 0 (no breathlessness) to 10 (maximum breathlessness).
Time frame: Baseline (week 1) and at the end of the intervention (week 8), during or immediately after the relevant activity or test.
Change in Anxiety Symptoms Measured by the Beck Anxiety Inventory
Anxiety symptoms will be assessed using the Beck Anxiety Inventory (BAI), a 21-item self-report questionnaire. Total scores range from 0 to 63, with higher scores indicating more severe anxiety symptoms.
Time frame: Baseline (week 1) and at the end of the intervention (week 8).
Change in Depressive Symptoms
Depressive symptoms will be assessed using the Beck Depression Inventory (BDI), a 21-item self-report questionnaire. Total scores range from 0 to 63, with higher scores indicating more severe depressive symptoms.
Time frame: Baseline (week 1) and at the end of the intervention (week 8).
Change in Heart Rate Variability (RMSSD)
Heart rate variability will be assessed using the root mean square of successive differences (RMSSD) derived from R-R intervals recorded with a Polar H10 heart rate sensor. Recordings will be obtained during a 5-minute resting period under standardized conditions and analyzed using Kubios HRV Standard software.
Time frame: Baseline (week 1) and at the end of the intervention (week 8).
Plan to share: No
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Started Sep 2026 (actual). Primary completion is estimated for Apr 2027, 7 months after the start.
Of 67 non-industry interventional studies with no phase under Generalized Anxiety Disorder, half reached primary completion within 35 months of starting (the median), counting those still running; a quarter within 17 and three quarters within 67. This study's planned 7 months is below that.
Counting every sponsor, half of 70 studies reached it within 33 months; a quarter within 17 and three quarters within 64.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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