Get on all fours on an exercise mat. Place your hands on the mat slightly wider than and in line with your shoulders. Your body should form a straight line from ankles to shoulders. Squeeze your core and lower your body until your chest nearly touches the floor. Then, keeping your core engaged, explosively push up through your arms so that your hands lift off of the floor. Keep your elbows slightly bent as you land, moving straight into lowering again. That’s one rep.