Here is one of the most functional exercises in the entire fitness world! The pull-up is a great workout for your upper back, biceps, core, and shoulders. It is more effective than the lat pulldown exercise, which although it is great for the upper back, it does not give you a full body workout as effectively. Plus, pull-ups can be difficult. There are plenty of people who can bench press 350 pounds in the gym. While that feat is awesome, ask how many guys in the gym can do 25…