ACSM Newsbriefs: PDF OnlyPhysical Activity Intensity How Much is Enough?Franks, B. Don Ph.D., FACSM; Welsch, Michael A. Ph.D.; Wood, Robert H. Ph.D.ACSM'S Health & Fitness Journal: November 1997 - Volume 1 - Issue 6 - p 14-19 Free © 1997 American College of Sports Medicine