The present study aims to investigate the effect of different exercise training in patients with chronic respiratory disease.

Background： Chronic respiratory and chronic obstructive pulmonary disease is the one of the major causes of global morbidity and mortality. Patients with chronic respiratory disease often experience exercise limitation and physical inactivity due to muscular weakness and severe dyspnea. Symptoms of COPD may contribute to activity restriction, deconditioning, and exercise intolerance. Pulmonary rehabilitation has been demonstrated to improve clinical outcomes and exercise capacity in patients with chronic respiratory disease. However, the optimal exercise training modality is remaining unclear.

Study Design： This is a one-year, single-centre, prospective randomized controlled trial

Methods： The investigators expected a total of 60 participants were be enrolled, then randomly assigned into three groups (control group, experimental-1, and experimental-2). All participants will receive a graded exercise test, then followed a 9-weeks of exercise training. After 9-weeks of exercise training, the maximal oxygen consumption will be analyzed as a primary outcome of this study. Physiological parameters, hemodynamic outcome, respiratory function, and strength of lower limb muscle will be recorded.

Effect： After 9 weeks' exercise training, VO2 will significantly improve in eccentric cycling exercise groups, furthermore, heart rate and perceived exertion will be lower in the eccentric cycling exercise combined with helmet ventilation.

Key words： Pulmonary rehabilitation; eccentric cycling exercise; helmet ventilation; chronic respiratory disease

Inclusion Criteria:

• Age between 20 and 80 years
• Diagnosed with chronic respiratory diseases
• Having undergone pulmonary rehabilitation for more than 3 months

Exclusion Criteria:

• Existing of tracheostomy
• Those who use oxygen therapy or ventilator at home
• Severe left heart failure (NYHA III-IV)
• Neuromuscular disease
• Acute exacerbation within the past three months
• Those who are unable to cooperate with the cardiopulmonary exercise test