You know you should exercise more. You want to exercise more. But sometimes it's tough to squeeze a full workout into your busy schedule. The good news: A number of published studies show that you can stay in shape and burn enough calories to maintain or lose weight by doing mini-workouts throughout the day. In fact, research has shown that short bouts of exercise—as few as three 10-minute sessions—are just as effective as long ones, provided the total cumulative workout time and intensity level are comparable. Repeat any of the following exercises for a minute.

1. Jumping jack Stand with feet together, then jump, separating legs and raising arms overhead. Land with feet hip-width apart, then jump feet back together and lower arms.

2. Stair running Run up a flight of stairs, pumping your arms, then walk down. Vary by taking two stairs at a time.