1. Department of Cardiology, University Heart Center, University Hospital Zurich, 8091 Zurich, Switzerland
2. Exercise Physiology Laboratory, Institute of Human Movement Sciences and Sport, Swiss Federal Institute of Technology in Zurich (ETH Zürich), 8092 Zurich, Switzerland
3. Zurich Center for Integrative Human Physiology, University of Zurich, 8006 Zurich, Switzerland