This exercise is great for entire abdominal area and your glutes.
Put your body in a pushup position. Put your elbows on the floor, forming 90 degree angle, and rest your body on your forearms. Arch back slightly out.
Raise your glutes toward the ceiling. When you are in a high bridge position, squeeze your abs tightly. Slowly lower back down to starting position. Repeat that motion, but don't let your back sag downwards.
Breathe out when you are raising your