My personal WOD for legs and back today, I call it the 1115.
4 Rounds of:
10 air squats (technically still perfecting them so 10 with good form will do)
10 Pull ups
10 Jump Ups (12/16/18/24″)
5 Pullups
I was beat by the end, I actually wanted to do another set but realized that my legs were getting wobbly and jumping up onto my deck with legs like that one more time may result in my face meeting my DIY project. I have to admit, even though it only took about 20 minutes to complete it really did feel like a good workout. My heart rate was over 160 which is rare for me and a true indicator that the intensity was where it should have been.
The air squats are tough since you have to go below horizontal and in the  past that has thrown my back out so I was a little nervous. Also, there is a great deal of technique to them and I am sure that given the shortness of my hamstrings and the tightness of my ITB that my technique is far from perfect. In fact I think I am victim of the “famous” butt wink.
All I can do is keep trying, do my best and what? (silence)…( my favourite part of the P90X series… You can almost hear the crickets.)
From the Crossfit site, a short demo of the air squat: Air Squat