1 Division of Pulmonary Medicine, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada; Faculty of Physical Education and Recreation, University of Alberta, Edmonton, Alberta, Canada.
2 Division of Pulmonary Medicine, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada.
3 Faculty of Physical Education and Recreation, University of Alberta, Edmonton, Alberta, Canada.
4 Division of Cardiology, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada.
5 Division of Pulmonary Medicine, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada; G. F. MacDonald Centre for Lung Health (Covenant Health), Edmonton, Alberta, Canada. Electronic address: michael.stickland@ualberta.ca.