1. Using a smith machine, lower the bar so that when you're standing next to it, it's about knee height.
2. Place your hands on the bar, slightly wider than shoulder-width apart, and then step your feet back so that your body is in a plank position. Your arms should be perpendicular to your body. This will be your starting position.
3. Keeping your back flat and abs braced, lower yourself down by flexing your elbows so that your chest nearly touches the bar.
4. Return to the starting position by pressing through your hands and contracting your pecs and triceps. Repeat for the recommended number of repetitions.