High-Intensity Progressive Inspiratory Muscle Training in Class III Obesity and Obstructive Sleep Apnea

High-Intensity Progressive Inspiratory Muscle Training in Class III Obesity and Obstructive Sleep Apnea: Study Protocol for a Prospective Nonconcurrent Multiple-Baseline Single-Case Experimental Design With Stability-Based Phase Transition

The purpose of this study is to evaluate the feasibility and effects of a 12-week high-intensity progressive Inspiratory Muscle Training (IMT) program in individuals with Class III obesity (BMI ≥ 40 kg/m²) and obstructive sleep apnea (OSA). Using a single-case experimental design (SCED) with multiple baselines, the study will investigate whether this respiratory intervention can reduce the severity of sleep apnea, as measured by the Apnea-Hypopnea Index (AHI), and improve inspiratory muscle strength and sleep quality. Participants will perform daily training sessions using a resistive loading device (POWERbreathe), with intensity progressing from 40% to 90% of their maximum inspiratory pressure.

Inclusion Criteria: -Adults (≥18 years).

• Of both genders.
• Class III obesity (BMI > 40 kg/m²).
• Diagnosis of OSA.
• Without neurological conditions that would prevent them from responding to the study assessments.

Exclusion Criteria:

• Systemic diseases (pulmonary, cardiac or renal).
• Are using medications that may affect muscle performance.
• Are currently using CPAP therapy.
• Conditions that could compromise adherence to the study protocol.