They are America's hottest fitness gurus, masters of motivation whose "body of work" includes some of America's most glamorous movie, music and TV personalities:

• Bob Greene helped Oprah Winfrey shed and keep off 85 pounds and run a marathon,
• Ray Kybartas coached Madonna through her transformation from pudgy to near perfect,
• Karen Voight instructs Hollywood's elite including Tina Turner, Elle MacPherson and Paula Abdul.

Now these trainers of the stars are offering their exercise secrets to the masses. Here is a sampling of their fitness philosophy gleaned from telephone interviews and their recent books.

Bob Greene holds a masters degree in exercise physiology from the University of Arizona, is traveling the country speaking about exercise for the Easy Spirit Fitness Forum and is co-author, with Oprah Winfrey, of Make the Connection: Ten Steps to a Better Body and Better Life.

His main message: "Too many people lead lives that are out of balance, over-eating and underexercising. Often, it's because they're under stress and use food as comfort. That's why people who are struggling with weight issues need to look at the rest of their life and figure out what situations lead to overeating."

Most common mistake: "Focusing on appearance rather than on health. The important thing is to do the behaviors: be active, eat right and feel good today. The results will follow."