Using your upper body to lift and extend your legs will stoke your calorie burn and hit tricky to trim back muscles. Start on floor in full plank position, feet together, hands directly under shoulders. Keeping palms planted, rotate torso to sit on floor on right hip, bent right knee on floor in front of you.
You don't have to stand upright to tone up, burn fat and expend calories. In fact, many fat-burning exercises work best lying down. A 2009 review published in .