Deep one-legged squats are possibly the best butt exercise ever invented. Combine this one with glutei hip ups for an exceptional leg and hip workout.
Chest and hip flexor stretch with rotation around the spine for a full body stretch and warm up.
If your stiff and sit a lot, you need this exercise! It's a tough one for a lot of people, but the pay off is incredible, especially if you have upper back and neck pain.