A sagging butt is generally caused by a lack of muscle definition in the gluteus maximus, the large muscles in the buttocks. In order to easily lift a sagging butt, it's key to include some very targeted exercises into your workout routine every week. Focusing your efforts on your lower body for two to three workouts each week will help build the gluteus maximus -- also known as the glutes -- up to a rounder, firmer shape. The easiest exercises for this are quite simple, and you can expect to start seeing improvement in the shape of your butt within the first four to six weeks of adapting your workout routine, with even further improvement around weeks eight to 10.
Squats are a key movement if you want to boost your butt. Targeting all muscles in your lower body, squats have a particularly high impact on your quadriceps and glutes. Body-weight squats are a good place to start if you haven't done a lot of training before, but move on to weighted barbell squats when you can. Simple weighted work is highly effective for building lean muscle mass, which is what you need to achieve in your gluteus maximus if you want your butt to stop sagging. Include squats in your workouts at least twice per week. Each time you should do three to five sets of squats, with eight to 12 repetitions per set.
The deadlift is one of the best exercises for developing the gluteus maximus. Because you have to generate a lot of force to lift the barbell off the floor, your glutes must be engaged for the duration of the lift. Not only do your glutes stabilize your body throughout the movement, but they also provide the bulk of the force needed at the top of the movement. For this reason, deadlifts will quickly and effectively start lifting your butt up into a rounder, more defined shape. Deadlift twice a week, performing three to five sets of deadlifts, with eight to 12 repetitions per set.
Walking lunges are also highly effective in boosting up the butt. They are easy to perform, and if you want to really say goodbye to the sag, start combining squats, deadlifts and walking lunges in the same workout a couple of times a week. Walking lunges with dumbbells target the glutes, upper quadriceps and hamstrings, improving the overall appearance of the area around your butt. Again, perform three to five sets of walking lunges, with eight to 12 repetitions per set.
The Lower-Body Bonus
There is extra benefit in working on your lower body a couple of times per week. An article from the University of New Mexico found that the lower body burns more energy during targeted workouts than any other part of the body, meaning you burn fat while simultaneously building lean muscle mass. Lower-body workouts also develop greater core stability and overall power. In order to continue improving the appearance of your butt, make sure you make use of the progressive overload principle: each time you work out, try to do a couple more repetitions of the exercise, or add a little weight, so the muscles you are targeting must adapt to each new challenge.