Core training?

[Wahine]

I'm trying to picture when you say the knee tuck, 'cause this is how I do my push ups too.

V.

Best done with your feet on the ball and hands on a surface at about the same height as the ball. As you puh-up, roll the ball towards your hands by bringing your knees towards your belly/chest. Your bum will come up a bit, try to keep your shins parallel to the floor. Phew, I'm tired describing it.

I'll also second crossfit. Awesome workouts, encorporating core with your strengthening exercises. Each workout is meant to be done in 20 min. If you want to go so hard that you puke that is.