1. Working Group Exercise Oncology, Division of Medical Oncology, National Center for Tumor Diseases (NCT) and Heidelberg University Hospital, Im Neuenheimer Feld 460, Heidelberg 69120, Germany
2. Department of Health Services Research, School of Medicine and Health Sciences, Carl von Ossietzky University, Ammerländer Heerstrasse 140, Building V04, Oldenburg 26046, Germany
3. Chair of Medical Sociology, Institute of Medical Sociology, Health Services Research and Rehabilitation Science, Faculty of Medicine, University of Cologne, Cologne, Germany