Jerrold Petrofsky, PhD, is a Professor of Physical Therapy and Director of the Research Laboratory for the School of Allied Health at Loma Linda University. He has almost 400 publications and has written two books and 12 chapters in books on cardiovascular physiology, exercise, and endocrinology. He has a PhD in physiology from Saint Louis University and undergraduate degrees in engineering from Washington University in Saint Louis and Ohio State University in Dayton Ohio.