Respond to the letter to the editor by Van't Hul et al. regarding the published manuscript "can do, don't do" are not the lazy ones: a longitudinal study on physical functioning in patients with COPD" by Sievi et al.(1)
Respir Res. 2020 May 13;21(1):114.
doi: 10.1186/s12931-020-01376-2.