The cable tricep extension is an isolation exercise that works your triceps. It will also engage stabilizing muscles in your shoulders and back, improving shoulder stability and mobility.
This is a similar movement to the dumbbell overhead tricep press, but there is a benefit using a cable. Due to gravity, using a dumbbell will provide you very little resistance at the top of the movement. While using a cable allows you to attain a full range of motion from top to bottom with constant tension directly placed on the triceps. Giving it a good stretch at the bottom position and a strong contraction at the top.
The triceps make up two thirds of your arm, so if you want big arms, you have to train them hard. Just like its name, the triceps are consisted of three muscles, all working together to achieve elbow extension. This exercise will work all three heads, but as any overhead exercise, it puts emphasis on the long head.
Keep your upper arm in the same place, The movement should be done only with the forearms. Moving your upper arms, will distribute some of the pressure away from your triceps to the shoulders.
You can spread the rope while pressing up until your hands are around shoulder width apart at the top. Returning it close together at the bottom, some people find that easier on the shoulder and elbow joints.
You can do this exercise standing up or sitting down. There isn't much difference, but standing up will require more muscle to stabilize your torso.
Keep your torso straight and with a slight lean forward. Make sure to resist the weight, and don't let your torso be pulled back.