1. Department of Kinesiology and Applied Physiology University of Colorado (C.B., D.R.S., M.B.M., D.S.D., L.F.S., P.P.J.), Boulder, Colorado 80309
2. Department of Medicine, University of Colorado Health Sciences Center (D.R.S.), Denver, Colorado 80262
3. Department of Medicine, University of Arizona (D.G.J.), Tucson, Arizona 85721