Acknowledgements
The authors would like to thank physiotherapists Iris Coosemans, Veronica Barbier, Lode Claes, Ilse Muylaert, Nele Vandenbergh and the staff of the Respiratory Rehabilitation Department and Pulmonary Function Department at the University Hospital Leuven for the collection of data and for providing the exercise training program. We are also thankful to Karen Denaux, Kristien de Bent, Dr. Nina Cardinaels, Maarten Spruyt, Sofie Verschueren, Vanessa Van Geel and Willem Dewit for the collection of biological material.The authors would also like to thank the teams from the Respiratory Division (E502) and the Centre for bone densitometry (E415) (UZ Gasthuisberg, Leuven, Belgium) for their assistance with the study assessments.