Many people get confused with the difference between Chin Ups and Pull Ups. In fact, often people don’t know that they are different. Here is an explanation and physiological reasoning behind the difference, and why one is easier than the other.
The regular Pull Up is a movement where you hang from Rings, or a bar, and pull yourself up. Your palms are facing away from your body and your knuckles are facing you. The muscles worked are the Forearms, Biceps, Rear Delts, Rhomboids, Traps and Lats.
The regular Chin Up is a movement where you hang from Rings, or a bar, and pull yourself up. Your palms are facing towards your body and your knuckles are facing away. The muscles worked are the Forearms, Biceps, Rear Delts, Rhomboids, Traps and Lats.
So on the face of it, these exercises seem almost identical. Except for one difference, which the hand angle. It is this difference which makes Chin ups significantly easier than Pull ups.
Many people incorrectly state ‘Chin ups use more biceps’, which is not scientifically accurate.
Here’s why Chin ups are easier than Pull ups
The Bicep muscle inserts onto the Radius Bone of the forearm. When the wrist is Supinated, as in Chin Ups, the Radius and Ulna bones run parallel to each other. When the wrist is Pronated, the Radius rotates and twists over the Ulna. Whilst this creates a stronger position for the bones, it also causes the bones to impinge the Bicep tendon. This stops the bicep from fully contracting. While you’re reading this, lift your arm up and tense your bicep; rotate your hand to see your bicep move from full contraction when your knuckles are towards you.
(Image from Lex Medicus Anatomy)
It is simply this movement of the bone that makes Pull ups harder than Chin ups, due to the impinged Bicep.
There is not more Bicep activation during Chin ups, but the muscle is simply in a superior (or non-impinged) position to perform the movement.
So which is best, Pull ups or Chins ups?
They are both excellent exercises. Neither is better than the other, Chin ups simply place the Bicep in a superior pulling position – hence why they are ‘easier’ than Pull ups.