Exercise intensity and energy balance in COPD: A randomized controlled trial.

<bold>Background:</bold> High-intensity exercise is recommended for pulmonary rehabilitation of chronic obstructive pulmonary disease (COPD) patients, but it can cause energy imbalance due to increased energy expenditure. <bold>Objective:</bold> This study explored how reducing exercise intensity affects energy balance in COPD patients experiencing weight loss due to high-intensity training. <bold>Methods:</bold> All the participants had high-intensity endurance and resistance training for a two-week preliminary period. Those who lost more than 1% of their weight were then randomized to either continue high-intensity exercise (AA group) or switch to a low-intensity exercise (AB group) for another two weeks (experimental period). <bold>Results:</bold> The analysis included thirty participants (AA group = 15, AB group = 15). The AA group showed significant increases in body composition, dietary intake, nutritional status, muscle strength and exercise capacity at week 4 versus week 2, with no significant changes in the AB group. After the experimental period, a greater proportion of the AA group had energy intake exceeding expenditure compared to the AB group (70% vs. 40%). <bold>Conclusions:</bold> In COPD patients who lost body weight during pulmonary rehabilitation with high-intensity exercise, continuing this exercise had a more positive effect on body composition, nutritional status, physical function, and energy balance than reducing exercise intensity. These results suggest the importance of continuing high-intensity exercise, alongside considerations for energy intake and nutritional therapy, even when body weight loss occurs during pulmonary rehabilitation in patients with COPD.