Effects of Inspiratory Muscle Training Added to a Swimming Program in Children With Asthma (IMT-SWIM-ASTHM)

Effects of Inspiratory Muscle Training Combined With a Structured Swimming Program on Pulmonary Function and Asthma Control in Children With Mild Asthma: A Randomized Controlled Trial

This randomized controlled trial investigated the effects of adding inspiratory muscle training (IMT) to a structured swimming program on pulmonary function, respiratory muscle strength, ventilatory capacity, perceived exertion, and asthma control in children with mild persistent asthma. Thirty children aged 8-11 years were randomly assigned to either a swimming plus IMT group or a swimming-only group. Both groups participated in a supervised 4-week swimming program, while the experimental group additionally performed IMT twice daily. Pulmonary function tests, respiratory muscle strength, and Childhood Asthma Control Test (C-ACT) scores were assessed before and after the intervention.

Study Overview

• Status: Completed
• Conditions: Asthma; Asthma Chronic; Asthma Control
• Intervention / Treatment: Other: Swimming Training Only (Control Group); Other: Swimming + Inspiratory Muscle Training (Experimental Group)

Detailed Description

Asthma-related airway obstruction and respiratory muscle dysfunction may limit exercise tolerance and disease control in children. Swimming is considered a safe and beneficial exercise modality for pediatric asthma due to its humid environment and controlled breathing patterns. Inspiratory muscle training specifically targets respiratory muscle weakness and may further enhance pulmonary adaptations. This parallel-group randomized controlled trial examined whether combining IMT with swimming training yields superior improvements in lung function, respiratory muscle strength, ventilatory capacity, perceived exertion, and asthma control compared with swimming training alone. The intervention lasted four weeks, with objective pulmonary and respiratory muscle assessments conducted pre- and post-intervention.

• Study Type: Interventional
• Enrollment (Actual): 30
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Trabzon, Ordu, Giresun, Rize, Artvin, Gümüşhane
    • Gümüşhane, Trabzon, Ordu, Giresun, Rize, Artvin, Gümüşhane, Turkey (Türkiye), 29600
      • Gumushane Univetsity

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Children aged 8-11 years
• Clinically diagnosed mild persistent asthma according to GINA guidelines
• Baseline FEV₁ ≥ 80% predicted
• Stable asthma treatment for at least 4 weeks
• Written informed consent from parents or guardians

Exclusion Criteria:

• Mild intermittent, moderate, or severe persistent asthma
• Acute asthma exacerbation during the study
• Other chronic respiratory, cardiovascular, or neuromuscular diseases
• Recent upper respiratory tract infection
• Use of medications affecting pulmonary function other than standard asthma therapy

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Other: Swimming Training Only (Control Group); Participants completed a supervised swimming training program for 4 weeks, consisting of three 60-minute sessions per week. Sessions included warm-up, main swimming exercises, and cool-down breathing exercises. Exercise intensity was maintained at approximately 65% of maximal heart rate.	Other: Swimming Training Only (Control Group); Participants completed a supervised swimming training program for 4 weeks, consisting of three 60-minute sessions per week. Sessions included warm-up, main swimming exercises, and cool-down breathing exercises. Exercise intensity was maintained at approximately 65% of maximal heart rate.; Other: Swimming + Inspiratory Muscle Training (Experimental Group); Participants completed the same swimming training program as the control group. In addition, inspiratory muscle training was performed using a threshold pressure-loading device. IMT was conducted twice daily, starting at 30% of maximal inspiratory pressure and progressively increased by 5% weekly, over a 4-week period.
Experimental: Swimming + Inspiratory Muscle Training (Experimental Group); Participants completed the same swimming training program as the control group. In addition, inspiratory muscle training was performed using a threshold pressure-loading device. IMT was conducted twice daily, starting at 30% of maximal inspiratory pressure and progressively increased by 5% weekly, over a 4-week period.	Other: Swimming Training Only (Control Group); Participants completed a supervised swimming training program for 4 weeks, consisting of three 60-minute sessions per week. Sessions included warm-up, main swimming exercises, and cool-down breathing exercises. Exercise intensity was maintained at approximately 65% of maximal heart rate.; Other: Swimming + Inspiratory Muscle Training (Experimental Group); Participants completed the same swimming training program as the control group. In addition, inspiratory muscle training was performed using a threshold pressure-loading device. IMT was conducted twice daily, starting at 30% of maximal inspiratory pressure and progressively increased by 5% weekly, over a 4-week period.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Maximal Inspiratory Pressure (MIP)	Measured using a handheld respiratory pressure device to assess inspiratory muscle strength.	4 weeks
Forced Expiratory Volume in 1 Second (FEV₁)	Assessed via spirometry to evaluate pulmonary function. Forced expiratory volume in one second (FEV₁) was measured using the spirometry method to assess lung function. FEV₁ values were reported as a percentage of the predicted value (% predicted) based on reference values. While there is no theoretical minimum or maximum limit for the measurement, higher FEV₁ values indicate better pulmonary function.	4 weeks
Childhood Asthma Control Test (C-ACT) Score	Validated questionnaire assessing asthma symptom control in children. The Childhood Asthma Control Test (C-ACT) is a self-report questionnaire used to assess the level of asthma symptom control in children over the past 4 weeks, with proven validity and reliability. The total scale score ranges from 0 to 27, with higher scores indicating better asthma control.	4 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Maximum Voluntary Ventilation (MVV)	Assessed via spirometry to evaluate pulmonary function. Maximum Voluntary Ventilation (MVV)	4 week
Peak Expiratory Flow (PEF)	Assessed via spirometry to evaluate pulmonary function. Peak Expiratory Flow (PEF)	4 week
Forced Vital Capacity (FVC)	Assessed via spirometry to evaluate pulmonary function. Forced Vital Capacity (FVC)	4 week
Rating of Perceived Exertion (Borg Scale)	Rating of Perceived Exertion (Borg Scale), The Borg Rating of Perceived Exertion Scale (Borg Scale; 6-20) is a validated and reliable measure used to assess the level of exertion individuals perceive during exercise or physical activity over the past 4 weeks. Scale scores range from 6 to 20, with higher scores indicating a higher level of perceived exertion and, consequently, a poorer outcome.	4 week

Collaborators and Investigators

• Sponsor: Gümüşhane Universıty
• Investigators: Principal Investigator: Coşkun YILMAZ, associate professor, Gümüşhane Universıty

Study record dates

Study Major Dates

• Study Start (Actual): January 25, 2025
• Primary Completion (Actual): February 25, 2025
• Study Completion (Actual): February 28, 2025

Study Registration Dates

• First Submitted: February 2, 2026
• First Submitted That Met QC Criteria: February 2, 2026
• First Posted (Actual): February 6, 2026

Study Record Updates

• Last Update Posted (Actual): April 15, 2026
• Last Update Submitted That Met QC Criteria: April 12, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: children; asthma; inspiratory muscle training; pulmonary function; swimming; asthma control
• Additional Relevant MeSH Terms: Immune System Diseases; Respiratory Tract Diseases; Lung Diseases; Bronchial Diseases; Lung Diseases, Obstructive; Respiratory Hypersensitivity; Hypersensitivity, Immediate; Hypersensitivity; Asthma; Motor Activity; Movement; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena; Investigative Techniques; Epidemiologic Research Design; Epidemiologic Methods; Research Design; Methods; Exercise; Locomotion; Control Groups; Swimming
• Other Study ID Numbers: 2025/024

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data will not be shared due to ethical restrictions and the inclusion of pediatric participants. Data sharing was not explicitly included in the informed consent, and sharing raw data could compromise participant confidentiality.

Drug and device information, study documents

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