Set your program

Decide what works best for you, such as 8 a.m. on Monday, Wednesday, and Friday. "You don't let anything interfere with that," advises Thompson. "That's not to say once a month something comes up you can't exercise. That's OK. It's when you're making excuses three, four, five days in a row -- that's a problem. It's got to be the highest priority because it's your health."