The In-and-Out Lunge works your butt, inner and outer thighs, and hamstrings.
-The Booty Camp Workout: In and Out Lunge. Start by doing diagonal lunges out to the sides. Make sure that your knee and toes are pointing in the same direction and sink down into the lunge before moving on. You'll do 10 lunges this way. Then turn around and do 10 crossover lunges. Step your foot across your body and sink into the lunge making sure, once again, that knee and toes are facing the same direction.