A round, shapely butt says a lot about its owner. It says that she put in a lot of hard work to sculpt the body of her dreams. By doing variations of the lunge -- a compound exercise that targets your hips, thighs and butt -- you'll work your gluteus muscles to the max. By adding weight and making minor changes to the basic lunge, you can get a fuller, rounder butt.
Your butt is made up of three muscles, the gluteus maximus, gluteus minimus and gluteus medius. The gluteus maximus is one of the largest and strongest muscles in your body and is responsible for hip extension, or moving your leg to the rear. The gluteus minimus and medius lie directly beneath your gluteus maximus and are in charge of hip abduction, or moving your leg away from the midline of your body.
In a basic forward lunge, start with your feet together and take a step forward, leading with your heel. Lower your body by flexing the hip of your front leg until your back lower leg is parallel to the ground. Keep your chest up and don't let your front knee go past your toes. Since your gluteus maximus is a very large muscle, you need to add weight to the exercise to increase muscle growth. Either use a barbell behind your neck or hold a dumbbell in each hand to increase the difficulty.
The placement of your feet during a lunge determines which muscle group is the main focus. When you take a step forward during a basic lunge, try to take as large a step as possible. A large lunge places emphasis on your gluteus maximus, while a shorter lunge places more emphasis on your quadriceps, or the front of your legs.
Altering the direction of the lunge can change which muscle groups are targeted the most. In a reverse lunge, the emphasis is on your glutes, when you step back instead of front. By placing your weight on your front heel when returning your leg to the starting position, you are putting the emphasis on your glutes. During a side lunge, your gluteus medius and minimus are the main focus. Perform a side lunge but stepping out laterally to the side, keep your weight in your heels and bend at your hips allowing your outer knee to bend. Squeeze your glutes as you return to the starting position.