He GX, Li N, Ren L, et al. - Considering the essentiality of pulmonary rehabilitation (PR) to manage patients with COPD, researchers sought to determine the suitable intensity of PR exercise training for patients with moderate-to-severe COPD. In this prospective multicenter randomized controlled trial, patients were randomly assigned to three groups with different intensities of PR, according to their maximum oxygen uptake percentage determined by cardiopulmonary exercise testing: low-, moderate-, and high-intensity exercise interventions. Following 20 weeks of exercise training, patients with moderate to severe COPD exhibited significant improvement in all the measured parameters in the high-intensity PR group. Findings suggest the necessity of intensive PR training among moderate COPD patients; compared with severe COPD patients, moderate COPD patients displayed higher improvement degrees from PR intervention. Among patients with severe COPD, more benefits can be acquired via high-intensity PR exercise if patients can tolerate it.