You most likely did a push-up at some stage in your life before beginning CrossFit, but you may not have done the full spectrum of motion pushups we use in CrossFit. Your arms should be absolutely straight at the top, and your chest should be in touch with the ground at the bottom.
2 Rounds for Time 25/20 calorie Assault Bike 25 Push-Ups 50 Air Squats 100 Double-Unders 50 Air Squats 25 Push-Ups 25/20 calorie Assault Bike Rest 3 minutes