1. Molecular Physiology Group, August Krogh Centre, Department of Nutrition, Exercise and Sport Sciences, University of Copenhagen, Copenhagen, Denmark;
2. Institute of Sports Medicine, Department of Orthopedic Surgery M, Bispebjerg Hospital and Center for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; and
3. Research Division, Joslin Diabetes Center and Department of Medicine, Harvard Medical School, Boston, Massachusetts