1 Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway.
2 Clinic of Cardiology, St. Olavs University Hospital, Trondheim, Norway.
3 Centre for Elite Sports Research, Department of Neuromedicine and Movement Science, Norwegian University of Science and Technology, Trondheim, Norway.
4 Norwegian Defense University College, Royal Norwegian Air Force Academy, Trondheim, Norway.
5 Department of Medicine, Levanger Hospital, Nord-Trøndelag Hospital Trust, Levanger, Norway.