High-Intensity Interval Alternating Concentric-Eccentric Training in Chronic Respiratory Disease

This randomized controlled trial aims to evaluate the effects of high-intensity interval training incorporating alternating concentric and eccentric cycling on functional performance in adults with chronic respiratory disease undergoing pulmonary rehabilitation. A total of 45 participants will be randomly assigned to one of three groups: high-intensity interval alternating concentric-eccentric training, high-intensity interval concentric training, or usual care. Participants in the exercise training groups will complete a 12-week supervised exercise program, while the usual-care group will continue routine care with self-regulated exercise intensity. Functional performance, exercise capacity, and patient-reported outcomes will be assessed before and after the intervention. The study seeks to determine whether incorporating eccentric exercise into high-intensity interval training can improve physical function while reducing cardiopulmonary and perceived exercise burden.

Inclusion Criteria: * Able and willing to provide written informed consent. Adults aged 18 years or older with chronic respiratory disease. Have participated in a pulmonary rehabilitation program for more than 3 months. For participants with an implanted cardioverter-defibrillator (ICD), the programmed maximum heart rate must be higher than the target heart rate used during exercise training. Considered medically suitable for exercise training by a specialist physician. Exclusion Criteria: * Presence of a tracheostomy. Use of long-term home oxygen therapy or home mechanical ventilation. Severe left-sided heart failure classified as New York Heart Association (NYHA) functional class III or IV. Diagnosis of a neuromuscular disease. Acute exacerbation of chronic obstructive pulmonary disease (COPD) within the previous 3 months. Unable to complete or cooperate with cardiopulmonary exercise testing.