1. Eberhard Karls Universität Tübingen, Institute of Sports Science , Wilhelmstraße 124, 72074 Tübingen , Germany
2. Medical University of Tübingen, Institute for Clinical Epidemiology and Applied Biostatistics , Silcherstraße 5, 72076 Tübingen , Germany
3. Charité—Universitätsmedizin Berlin, corporate member of Freie Universität, Berlin and Humboldt-Universität zu Berlin, Institute of Occupational Medicine , Augustenburger Platz 1, 13353 Berlin , Germany