Advanced Push for Paleo Fitness: The One-Arm One-Leg Push-Up
Set up at the top of your push-up position and lift one arm and the opposite leg off the ground.
For example, if you lift your left arm, lift your right leg off the ground; if you lift your right arm, lift you left leg. Take time to stabilize yourself before moving on to the next step. You should also remain on the ball of your foot throughout the movement.