Effects of exercise intensity on nutritional status, body composition, and energy balance in patients with COPD: a randomized controlled trial

BackgroundHigh-intensity exercise is recommended for the pulmonary rehabilitation of patients with chronic obstructive pulmonary disease (COPD); however, it can cause an energy imbalance due to increased energy expenditure. Here, we aimed to explore the effect of reducing exercise intensity on energy balance in patients with COPD experiencing high-intensity training-induced weight loss.MethodsAll participants underwent high-intensity endurance and resistance training for a 2-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 low-intensity exercise (AB group) for another 2 weeks (experimental period).ResultsThe analysis included 30 participants (AA, n = 15; AB, n = 15). The AA group showed significant increases in body composition, dietary intake, nutritional status, muscle strength, and exercise capacity at week 4 than at 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 than did the AB group (80% vs. 40%).ConclusionsIn patients with COPD 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 did reducing exercise intensity. These results suggest the importance of continuing high-intensity exercise, while taking into consideration energy intake and nutritional therapy, even when body weight loss occurs during pulmonary rehabilitation in patients with COPD.Trial registrationThis study was retrospectively registered on the UMIN-CTR as UMIN000050976 on May 5, 2023.