Abdominal Air Pressure Resistance Versus Abdominal Weight Training Versus Breathing Exercise for Improving Diaphragmatic Strength, Endurance, and Physiological Responses in Young Healthy Adults: A Study Protocol for RCT

Summary

This study aims to compare the effects of abdominal air pressure resistance training, abdominal weight training, and breathing exercises on diaphragmatic strength, endurance, and physiological responses in young healthy adults.

Forty-two healthy adults aged 18-35 years will be randomly allocated to one of three groups: abdominal air pressure resistance training, abdominal weight training, or breathing exercises. Participants will complete supervised training sessions three times per week for eight weeks, with standardized breathing cadence, training volume, and therapist contact time across groups.

This trial will provide the first direct comparison of a programmable pneumatic abdominal loading method with traditional abdominal weight loading and standard breathing exercises in healthy young adults. The findings will help determine the relative effectiveness, tolerability, and safety of these interventions for enhancing diaphragmatic function. The results may contribute to the development of evidence-based respiratory muscle training strategies for rehabilitation, health promotion, and performance enhancement.

Conditions

• Diaphragm Thickness
• Dyspnoea

Interventions

OTHER

Abdominal Air Pressure Resistance Training

In the AAPR group, resisted diaphragmatic breathing will be performed using a pneumatic abdominal garment or cuff capable of delivering quantifiable air pressure. Training will be initiated at a pressure level that elicited a moderate perceived breathing effort, corresponding to a Borg Rating of Perceived Exertion (RPE) of approximately 4-5, or within a predefined pressure range (e.g., 5-10 cmH₂O), depending on device capability. Progressive overload will be applied through weekly increases of 1-2 cmH₂O, provided predefined symptom tolerance criteria were satisfied. Each session consisted of 4-6 sets of resisted diaphragmatic breathing, with each set lasting 2-3 minutes and separated by rest periods of 1-2 minutes. During each session, the applied pressure, perceived exertion, and symptom responses will be recorded.

OTHER

Abdominal Weight Training (AWT)

In the AWT group, diaphragmatic breathing will be performed with an external load applied to the anterior abdominal wall using a standardized sandbag or weight pack, with participants positioned in supine crook-lying. Load prescription will be implemented using a pre-specified method, which included either a fixed initial load of 2-5 kg with weekly increments of 0.5-1 kg as tolerated, an initial load corresponding to 3-5% of body mass with weekly progression, or load titration based on perceived exertion targeting a Borg RPE of 4-5 during training sets. Training volume, set duration, and rest intervals will be matched to those of the AAPR group. For each session, the load applied, perceived exertion, and symptom responses will be documented.

OTHER

Breathing Exercise Control (BE)

In the BE control group, standardized diaphragmatic breathing combined with paced slow deep breathing will be performed without the application of external resistance. Training duration, breathing cadence, number of sets, and rest intervals will be matched to those used in the loaded intervention groups. Perceived exertion and symptom responses will be documented during each session.

Sponsors & Collaborators

• University of Sharjah

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

35 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2026-08-30

Primary Completion

2026-11-30

Completion

2026-11-30