Pull ups are one of the cornerstone exercises to any body-weight routine, they are also hugely beneficial to any weight training routine as well. They strengthen your back, your upper and lower arms, your core and they improve your grip.
The beauty of the pull up, like many body-weight exercises, is that you don't need any big fancy machine to do them - all you need is a bar and a sturdy door frame. If you want to add this incredible strength building exercise to your repertoire, here are the best of the best in portable pull up bars:
Best Pull-Up Bar