AKA Chin, pull-up
The chin-up is a simple and effective upper body pulling strength exercise that also can help with shoulder mobility.
Hang from a pull-up bar with your hands supinated (palms facing you) and just outside shoulder width, allowing your shoulder to open completely. Squeeze your shoulder blades back and down and pull with the arms to bring your chin above the bar, trying to continue pulling the shoulders and arms back in the top position to finish with a strong arch in the back. Lower under control until the elbows are completely extended and shoulders are fully open again.
The natural tendency is to round the back as you near the bar, but it’s important to arch instead to fully engage all of the back musculature. It’s equally important to ensure each rep starts from a genuinely open shoulder position—this will ensure proper shoulder mobility and health.
The chin-up strengthens the back and arms in opposition to vertical pressing motions common in weightlifting training and helps keep the shoulders and upper back balanced and healthy. The chin-up emphasizes the biceps a little more than the pull-up and can also be used as an alternative to avoid pain in the pull-up and vice-versa.
Sets of 5-10 reps are usually appropriate, and often a good way to prescribe chin-ups is with a total number of reps to be completed as possible (i.e. as many reps per set as can be done until reaching the total). Resistance can be reduced for those unable to perform chin-ups with their full body weight by using rubber bands to partially unload weight as necessary.
The chin-up can be done with wider or narrower grips, although usually the same grip with used for the jerk and press is ideal. The hands can be pronated (palms facing forward), in which case the exercise would then be called a pull-up.