Dose-response relationship between physical activity and mortality in people with non-communicable diseases: a study protocol for the systematic review and meta-analysis of cohort studies - Geidl, Wolfgang; Schlesinger, Sabrina; Mino, Eriselda; Miranda, Lorena; Ryan, Anna; Bartsch, Katja; Janz, Lukas; Pfeifer, Klaus (Friedrich-Alexander-Universität Erlangen-Nürnberg, 2019)