Burpee

Begin in a standing position. Squat down and place your hands on the floor directly in front of your feet.
Jump your feet back to a high plank position. Immediately lower your chest to the floor to perform a push-up.
Push back up to the plank position and then jump your feet forward, returning to the squat position.
From the squat, explode upwards into a jump, raising your arms overhead. Land softly to complete one repetition.

Tips

When you jump your feet back to the plank position, land with your hands directly under your shoulders and your body in a straight line from head to heels before lowering into the push-up.
At the top of the jump, extend your hips fully and reach your arms overhead so the movement is complete before you land.
Land from the final jump with soft knees, absorbing the impact through your hips and legs rather than letting your knees lock out on contact.

Skipping the push-up by only lowering the hips to the floor instead of bringing the chest down, leaving the upper-body portion of the repetition incomplete.
Letting the hips rise well above shoulder height during the plank phase, so the body is in a pike position rather than a straight line when performing the push-up.
Jumping the feet forward and landing them well behind the hands during the return to the squat, which forces the hips to stay low and makes the upward jump difficult to execute.