Muscle Group: Triceps
As the name indicates this is an old-school exercise. Fixed Bar Triceps Extensions fully stretch and develop the triceps.
Find a fixed horizontal bar positioned at about waist height, a smith machine is great for this.
Grab the bar with an overhand grip, hands about shoulder width apart. Lock your arms out to support your weight, then move your feet back until you are in a semi-push-up position above the bar.
Now bend your arms and lower your body so that your head comes down under the bar as far as you can go. When you feel a deep stretch in your tris, press forward with your arms and raise yourself back to the starting position, arms locked out.