Acute IMT Intensity Effects in Male Smokers

Not Applicable

Not yet recruiting

• Conditions: Smokers

• Registration Number: NCT07200895
• Lead Sponsor: FATMA DİLARA AKAR ÇAMYAR

Brief Summary

Acute IMT Intensity Effects in Male Smokers

Detailed Description

Cigarette smoking can impair respiratory muscle function by reducing inspiratory strength and endurance; Inspiratory Muscle Training (IMT) is a rehabilitative strategy that uses resistive breathing to strengthen the diaphragm and accessory inspiratory muscles. It may temporarily influence autonomic responses and muscle performance. This randomised, parallel-group study will investigate the immediate effects of two IMT intensities in male smokers. Thirty-four male participants who currently smoke will be randomly assigned to one of two groups: IMT at 30% of maximal inspiratory pressure (MIP) or IMT at 60% of MIP. Prior to IMT, all participants will complete a standardised diaphragmatic breathing warm-up (3 sets of 10 repetitions; approximately 5 minutes). IMT will be administered with a threshold device (e. g., Powerbreathe®), with each group performing 3 sets of 30 breaths at the assigned intensity over approximately 15 minutes under supervision. Participants will be monitored for transient discomfort or fatigue. Outcomes will be assessed immediately before and after the session. These will include respiratory muscle strength (MIP, maximal expiratory pressure, MEP), peripheral muscle performance (handgrip strength in both dominant and non-dominant hands), and vital signs (heart rate, oxygen saturation, respiratory rate, systolic and diastolic blood pressure), along with perceived exertion using the Borg scale. The primary outcome will be a change in MIP (cmH₂O and % predicted); secondary outcomes will include changes in MEP, handgrip strength, vital signs, and perceived exertion. Data will be analysed using appropriate paired and independent tests (parametric or non-parametric based on distributional checks) in IBM SPSS v 27. By comparing low- and higher-intensity IMT within a single supervised session, the study aims to identify a practical early-intervention intensity that can acutely enhance inspiratory muscle function in male smokers and potentially inform broader pulmonary rehabilitation strategies.

Study Timeline

• Status Verified: 2025-09
• Study First Submitted: 2025-09-23
• Study First Submitted QC: 2025-09-23
• Last Update Submitted: 2025-09-30
• Study Start: 2025-10-01
• Study First Posted: 2025-10-01
• Last Update Posted: 2025-10-02
• Primary Completion: 2025-12
• Study Completion: 2026-01-01

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: Male
• Target Recruitment: 34

Inclusion Criteria

• Male, 18-25 years of age.
• Current cigarette smoker for ≥1 year (regular use).
• No known acute or chronic medical condition.

Exclusion Criteria

• History of any musculoskeletal injury that may limit participation.
• History of chest pain during physical activity.
• Current use of any medication.
• Symptoms of dizziness or balance loss.
• Diagnosis of hemophilia or history of vascular/cardiovascular disease affecting circulation.
• Presence of any acute illness at screening or on the test day.
• Inability to complete the procedures due to physical limitation.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Primary Outcome Measures

Name	Time	Method
Change in Maximal Inspiratory Pressure (MIP), cmH₂O and % predicted	Baseline (pre-session) to immediately post-session (within ~5 minutes after IMT)	MIP will be measured using a calibrated mouth pressure meter/threshold device per standard procedures with a nose clip and from residual volume. The primary endpoint is the within-participant change (post-pre) expressed in cmH₂O and as % predicted based on reference equations. Higher values indicate greater inspiratory muscle strength.

Secondary Outcome Measures

Name	Time	Method
Change in Maximal Expiratory Pressure (MEP), cmH₂O and % predicted	Baseline to immediately post-session	MEP will be assessed with the same device from total lung capacity. Endpoint is post-pre change (cmH₂O and % predicted). Higher values indicate greater expiratory muscle strength.
Change in Handgrip Strength (dominant and non-dominant), kg	Baseline to immediately post-session	Assessed with a calibrated hand dynamometer (e.g., Jamar). Best of three trials for each hand recorded. Endpoint is post-pre change (kg).
Change in Heart Rate, Change in Respiratory Rate, Change in Oxygen Saturation, Change in Systolic and Diastolic Blood Pressure, Change in Perceived Exertion	Baseline to immediately post-session	* Measured at rest using a pulse oximeter or cardiac monitor after 3-5 minutes seated rest. Endpoint is post-pre change (bpm).; * Counted over 60 seconds at rest. Endpoint is post-pre change (breaths/min).; * Measured by pulse oximetry with the participant seated and at rest. Endpoint is post-pre change (%).; * Automated sphygmomanometer, seated, appropriate cuff size, two readings averaged if needed. Endpoint is post-pre change (mmHg).; * Global rating of exertion collected at rest (pre) and within 1-2 minutes after IMT. Endpoint is post-pre change (points).

Trial Locations

Locations (1)

Biruni University; Istanbul, Turkey (Türkiye)