Why not give these metabolic circuits a try. When we train them, we also incorporate stance work and transitions into the circuits. Here are two basic ones:
Do them as fast as you can. Keep a timer to try and improve each set. 3-5 sets should get your heart rate up.
Circuit 1
Lunges- 24
Squats- 24
Jump Lunges- 24
Jump Squats- 12
Circuit 2
Squat Jumps-20
Squat Thrusts- 20
Squat Thrust Jumps- 10
btw, The first few lines of your post reads funny
Good luck on the "Ass building"... LOL
"If you are patient in one moment of anger, you will escape a hundred days of sorrow."
"He who asks is a fool for five minutes, but he who does not ask remains a fool forever."
- Ancient Chinese Proverbs