"Don't believe anyone who says you have to exercise an hour every day for noticeable results," says Jill Coleman, fitness coordinator at Wake Forest University in Winston-Salem, North Carolina, and coauthor of the workout guide My Gym Trainer (My Trainer Fitness). Shorter workouts with more intensity allow you to burn more calories and fat. "Most people are willing to work harder when they know their exercise routine isn't going to last long," explains Coleman, who designed this plan. "Plus, brief bouts of physical activity are easier to fit into busy schedules. You can reach your goals with just three sessions per week." Strength moves, like those here, boost metabolism for hours post- workout and increase bone mineral density. In addition, strength training is the only way you can change the shape of the body, adding curves and definition.