1 Department of Family Medicine, Kaiser Permanente Medical Center, Fontana, Calif. Electronic address: Robert.E.Sallis@kp.org.
2 Cardiovascular Performance Program, Division of Cardiology, Massachusetts General Hospital, Boston.
3 Preventive Cardiology/Cardiac Rehabilitation, William Beaumont Hospital, Royal Oak, Mich; Oakland University William Beaumont School of Medicine, Rochester, Mich.
4 American College of Sports Medicine, Indianapolis, Ind.