Bodyweight Pull Up

Helping to build width in the back by focussing on the Lats, take a fairly wide grip. Keep control on the way up and on the way down. Raise your body up so that your chin comes level with the bar.
This is the standard version. Many variations are possible, eg by changing the width and direction of the grip (see for example, Close Grip Pull Up), and by adding weight, often with a belt. Many gyms also have a machine which offers a supported version of this exercise, where you kneel on a pad which helps lift you up.
with UK fitness model, Ben Bray.