1. From the Institute for Exercise and Environmental Medicine (Q.F., T.B.V., S.S., B.D.L.), Texas Health Presbyterian Hospital Dallas, Dallas, Tex; University of Texas Southwestern Medical Center at Dallas (Q.F., S.S., R.J.A., B.D.L.), Dallas, Tex; Brigham and Women’s Hospital (G.H.W.), Harvard Medical School, Boston, Mass.