This abs workout, designed by Angela Corcoran, a personal trainer at Equinox in New York City and professor of exercise physiology at Queens College in Flushing, New York, will help you build a stronger core by targeting different abdominal muscles, boosting your metabolism, and burning belly fat.
Place a 3- to 5-pound weight (or a large book) on a hip-height chair or table.
Stand in front of the surface with your back to the object. Twist your entire torso to your left, pick up the weight, then twist in the opposite direction and put the object back on the table. For a small object, like a weight, use just one hand. For a large object, like a book, use both hands. Reverse directions to complete one rep.
Be sure to stay upright and keep your hips facing forward to properly challenge your core muscles. During the exercise keep your hips resting lightly against the table or chair to make sure you're rotating from the spine and targeting your obliques.
Do 15 to 20 reps.