Q. I am 21 years old, 60 pounds overweight and very out of shape. I want to start exercising, but no matter what I do, regardless of whether it's jogging or an aerobics video, I am in pain and exhausted. After a couple of weeks, I quit, and then I feel like a failure. How can I be more successful at sticking with it?

A. "Start by setting realistic goals," says CC Cunningham, M.S., an Evanston, Ill., trainer and a spokeswoman for the American Council on Exercise. Instead of jumping right into a jogging program -- which is bound to leave you wiped out, if not injured -- start by walking for 15 minutes three days a week, adding five minutes to your walks every other week. Focus on simply getting into the habit of exercising. "It's not about how far, how long or how hard you exercise," Cunningham says. "It's about making the commitment. Once you get the habit developed, the exercise won't be a chore. It'll be something you actually enjoy and look forward to."

On the video front, choose tapes designed specifically for novices, and let yourself push the "pause" button to stop before the tape has ended. "There's no failure in not doing the whole video," Cunningham says. "Success just means being able to do more each time."

Cunningham suggests tracking your workouts in an exercise diary so you can appreciate your accomplishments. When you reach your short-term fitness goals -- such as working out three times a week for one month -- reward yourself. "Treat yourself to a massage or a new CD," she says. "Success isn't necessarily in the quantity of exercise but in the effort."