It is very important to understand how important form is in performing these exercises. The picture above will help you understand the muscle anatomy of these exercises.

The chin up or also known as the underhand grip pull up doesn’t just work your lats, the biceps are also involved. If you are a beginner who can’t do an overhand grip pull up, then do chin ups until you are strong enough to do pull ups.

Pull ups and chin ups target mainly your lats, arms and forearms. Chin ups focus more on your biceps and also activate your chest. For that reason it can be integrated into a program focused on training arm region. The trapezius (middle and lower portions ), rhomboids and pectorals are also involved. This exercise requires greater strength, it is easier to perform using high pulley.

Exercise Instructions

1. Grasp an overhead horizontal bar with and under grip so that your little fingers are 6 to 12 inches apart.

2. Starting from a dead hang, position with arms entirely straight, pull upward until your chin is above the level of the bar.

3. Lower under control, and repeat.


The under grip chin up is considered a compound movement for the biceps. The primary muscle group is the biceps and secondary muscle groups include the front deltoids (shoulders), forearms and back.

This exercise can be mistaken for close grip chin ups, they are very close. However, the only difference is how you pull your body upwards. Instead of concentrating on using your back to pull your body up, you’re going to be focusing on your biceps. This makes this exercise especially difficult.

If you’re new to this exercise, you should try this on a lat machine first. This is one tough exercise to do, however, it is one of the best biceps builders out there.

Concentrate on squeezing at the top and come down nice and slow.