Exercise can increase butt size by increasing glute muscle mass, or decrease it by reducing overall body fat. To achieve your personal fitness goals, it is important to know the difference. One aspect that should be remembered, though, is that increasing the size of the gluteus maximus muscle will usually only be visible once you've achieved low body fat. Because heavy exercises can stimulate fat burning by increasing anabolic hormones, and the glute is utilized in the heaviest of exercises, having well-developed glutes can actually help you reduce butt size in the long run, depending on your body composition.
The intensity of the exercise is the first clue as to whether it will build or decrease butt size. Less intense exercise is aerobic, utilizing oxygen to process fuel for the muscles. Your muscles are strong enough to perform this type of activity, so instead of your muscles building to increase your strength, your cardiovascular system builds to increase performance duration. These exercises, even if they utilize the glutes like walking, running, rowing and cycling do, will reduce your butt size as they burn calories and reduce body fat and even muscle, depending on how low your calorie intake is.
Even exercises that are usually performed aerobically can build glute muscles if you do them in such a way that you are unable to perform them for long. Sprinting for short periods will increase the size of the gluteus maximus muscles, while jogging for a half hour won't. Exercises such as deadlift, squat and leg press can massively increase the size of your glutes, which "Strength Training Anatomy" explains is already the largest muscle in the human body. Sets of these exercises last for only a minute or two, while aerobic activity that reduces body fat and sometimes even muscle can be performed for hours once you've strengthened your cardiovascular system.
Even bodybuilders taking hormones to increase their strength and improve their ability to heal will typically only exercise their glutes once a week. Exercises like the squat, deadlift and leg press require long periods of time to recover from, and should never be performed more than twice a week. Many powerlifters only perform deadlifts, the ultimate glute building exercise, once every two weeks. On the other hand, MayoClinic.com advises that you perform 150 minutes of aerobic activity a week. A brisk 30-minute walk five days a week will reduce excess fat and decrease butt size.
Spot Reduction Myth
It is important to understand that spot reduction is a myth. While you must work the butt specifically to increase its size, to decrease the size of your butt you must perform aerobic exercise that reduces total body fat. The American Council on Exercise explains that performing aerobic exercises utilizing your butt will not cause your body to burn fat more quickly from your butt.