The best exercises to reduce the size of the waist are cardiovascular activities and moves that target the transversus abdominis, such as the side plank-up and fly-up. To get a smaller waist, an individual needs to reduce her body fat percentage and perform exercises that strengthen her stomach muscles.
Cardiovascular exercises, such as running, biking, swimming, dancing and brisk walking, help exercisers burn more calories. When an individual burns more calories than she consumes, she is able to reduce her amount of body fat. Though it is impossible to spot reduce body fat, reducing the overall body fat percentage helps decrease the size of the waist. Harvard Medical School recommends 30 to 60 minutes of cardiovascular exercise each day.
The side plank-up is performed by lying on the side of the body with the feet staggered for support and the forearm perpendicular to the torso. The hips are lifted so that the body forms a straight line; the body is then returned to the original position.
With the fly-up, the legs are held against the wall with the knees at a 90-degree angle. The legs are extended against the wall as the torso rolls forward as the hands touch the feet. The abs should be kept tight the entire time.
Abdominal strength moves should be performed three times a week.