Dan Isaacson was the first personal trainer in Hollywood and has worked with Meg Ryan, Demi Moore, Richard Gere, Tyra Banks, Jack Nicholson, Robin Williams, Wesley Snipes, Alec Baldwin, Kirstie Alley, Michael Keaton, Lawrence Fishburne, Andy Garcia, Benecio Del Torro, Ethan Hawke, Freddie Prinze Jr., Sean Astin, Ryan Phillipe, Jon Voight, Rick Dees, Jamie Lee Curtis, Leslie Ann Warren, Linda Evans, Linda Grey, Melissa Gilbert, Victoria Principal, and supermodel Vendela among many others. He co-authored John Travolta's workout book, "Staying Fit," co-hosted Jane Fonda's work-out videos, appeared on Oprah and was previously "Good Morning America's first health and fitness expert. Dr. Greg Payne is a pre-eminent expert on health and fitness. He is a professor in the Department of Human Performance at San Jose State University and is the physical science expert for the book. In 2000, Payne was invited to become a member of the prestigious Academy of Kinesiology and Physical Education-one of his many honors. Mark Laska is an entertainment publicist and health book author. His books include "Pilates Powerhouse," "Body-Fat Breakthrough," and "Hot Point Fitness."