There are basically the same cable exercise, executed with a different hand grip. But, oh! What a difference the grip makes! Putting these two together will give you a far more complete triceps workout than either one alone. Here's what it looks like:
Attach a bent bar to the upper connection of a cable machine. Stand in front of the cable machine with your legs in a slight scissor position so that one leg is stepped slightly forward and the other leg is stepped slightly back. Hold the bar up at chest level in both hands with your palms down, and your pinkies are on the outside bend of the bar. Your elbows should be bent and held in at your sides. Use your triceps to push the bar down toward your thighs. Keep your elbows in close to your body as you descend to concentrate the work in the triceps. When your arms are fully extended and the bar is down in front of your thighs, reverse motion and bring the bar back up to starting position.
So far, so good. Here are the strengths of the tricep press-downs:
Work all heads: Your triceps get their name from the three heads (lateral, long, and medial) into which the muscle forks at the bottom. The trick of tricep work is, first and foremost, to hit all three heads of the muscle. Press-downs are great for this, as this exercise spreads the work thoroughly among all three. It also targets your anacondas (just on the outside of your elbow).