1. Department of Clinical Gerontology and Geriatric Rehabilitation, Robert Bosch Hospital , Stuttgart , Germany
2. Institute of Sports and Sports Sciences, Heidelberg University , Heidelberg , Germany
3. Department of Health Economics and Health Services Research, University Medical Center Hamburg-Eppendorf , Hamburg , Germany
4. Network Aging Research, Heidelberg University , Heidelberg , Germany
5. Institute of Epidemiology and Medical Biometry, Ulm University , Ulm , Germany
6. IB University of Health and Social Sciences , Study Centre Stuttgart, Stuttgart , Germany
7. Faculty of Health Sciences , University of Sydney, Sydney , Australia
8. School of Health Sciences , Faculty of Biology, Medicine & Health, , Manchester M13 9PL , UK
9. The University of Manchester , Faculty of Biology, Medicine & Health, , Manchester M13 9PL , UK
10. Manchester University NHS Foundation Trust , Manchester , UK
11. Manchester Academic Health Science Centre , Manchester , UK
12. Human Performance Research Centre , Department of Sport Science, , Konstanz , Germany
13. University of Konstanz , Department of Sport Science, , Konstanz , Germany