Try these 3 simple exercises to help firm your butt!

Skater Stride

While walking, take a large step diagonally forward to the right with the right foot, toes pointing forward.  Sink in to the lunge, bending both knees 90 degrees, as you bring your left elbow toward your right knee and swing your right arm straight back. Press off left big toe to bring left leg forward, brushing it past your right leg, then swinging it forward out to the left diagonal to plant left foot, toes forward. Do 25 steps to each side, alternating legs.

Power Lunge with Leg Lift

While walking, lunge forward with left leg, both knees bent 90 degrees. With hands in fists and elbows bent at 90 degrees, bring your right fist toward your nose and your left behind you. Shift your weight onto your left leg, straightening it; lower arms and lift your right leg out and back on a diagonal as high as you can. Bring your right leg forward into a lunge; repeat on that side. Do 25 reps per leg, alternating sides.

High-Knee Cross

While walking, tighten abs and lift your bent knee as high as you can directly in front of you, coming up on your right toes. Simultaneously bend your right elbow 90 degrees, bringing it across your body towards your left knee. Hold for 1 count, then lower your left foot to step forward. Repeat with your right leg. Do 25 reps per leg, alternating sides.