Short Term Effects of Early Respiratory Muscle Training on Respiratory Muscle Strength in Inpatient Acute Stroke

Short-Term Effects of Early Combined High-Intensity Interval Inspiratory and Expiratory Muscle Training on Respiratory Muscle Strength in Inpatients With Acute Stroke

This study aims to determine the early effectiveness of combined high-intensity interval inspiratory and expiratory muscle training in hospitalized patients with acute stroke. Participants will be assigned to receive either combined high-intensity interval inspiratory and expiratory muscle training or conventional diaphragmatic breathing exercises.

The main questions this study aims to answer are whether the combined high-intensity interval inspiratory and expiratory muscle training can improve:

• inspiratory muscle strength, measured using maximal inspiratory pressure;
• expiratory muscle strength, measured using maximal expiratory pressure;
• chest expansion, measured using thoracic expansion; and
• the ability to sustain speech on a single breath, measured using the single-breath count test.

Researchers will compare changes before and after the intervention between the two groups to determine whether combined high-intensity interval inspiratory and expiratory muscle training provides greater early improvement than conventional diaphragmatic breathing exercises in hospitalized patients with acute stroke.

Inclusion Criteria:

• Male or female participants aged 18 years or older.
• First-ever acute ischemic stroke, with stroke onset 2 to 14 days before enrollment, confirmed by computed tomography (CT) or magnetic resonance imaging (MRI).
• National Institutes of Health Stroke Scale (NIHSS) score ≥5, with the presence of hemiparesis.
• Baseline maximal inspiratory pressure (MIP) <80 cmH₂O.
• Baseline maximal expiratory pressure (MEP) <68 cmH₂O.
• Able to understand instructions and participate in the respiratory muscle training program.
• Willing to comply with the study protocol and provide written informed consent.

Exclusion Criteria:

• Resting blood pressure >160/100 mmHg.
• Resting peripheral oxygen saturation (SpO₂) <92%.
• Resting heart rate <40 beats/min or >110 beats/min.
• Fever, defined as body temperature ≥37.5°C.
• Previous participation in or experience with a respiratory muscle training program.
• Presence of chronic pulmonary disease.
• Presence of a tracheostomy tube.
• Presence of unstable cardiac disease.
• Presence of another neurological disorder associated with respiratory dysfunction.
• Presence of an orthopedic or musculoskeletal condition that significantly interferes with respiratory function or the ability to perform respiratory muscle training.
• History of major thoracic or abdominal surgery within the previous 3 months.