1. Departments of Physiology (V.L.A., M.T.E.H., E.A.B., D.H.J.T., T.M.H.E.), Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands.
2. Cardiology (V.L.A.), Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands.
3. Division of Cardiology, Hartford Hospital, CT (P.D.T.).
4. Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, UK (E.A.B., K.P.G., D.H.J.T., T.M.H.E.).