The Pull up. A great bread and butter exercise for the upper body just like squats are for the lower body. Both are great as they burn more calories than many other exercises due to the volume of muscle groups that are used within one movement.
Here are just a few reasons why you should add pull ups in to your workout routine.
Compound Movement
A compound exercise works out multiple muscle groups at the same time. Everyone knows that squats are the best exercise for your lower body, given the number of muscle groups they work out at once. Think of pullups as squats for your upper body. The exercise targets your biceps, forearms and most of the muscles in your back.
Grip Strength
Pull ups increase your grip strength which is crucial for anybody that weight trains. It will have an positive affect on movements such as deadlifts , weighted walking lunges , bent over rows as grip plays such as major factor in all 3 movements.
Convenience
A pullup is extremely convenient because you can do them in almost any open door frame. All you need is a bar and your body to get in a workout. You can buy a bar that fits securely into a door frame and will support your weight without spending a lot of money. If you live near a park you could use a tree ( make sure its strong enough to take your weight) or most parks will have a kids play ground that will normally have climbing frames that you can do them off.
Calorie Burning
As stated earlier. A pull up uses a lot muscle groups in one movement. The more muscle groups used within a movement, the more calories used to do so. Rather than thinking of cardio for fat loss use weight training instead as you use process calories at the time and build muscle tissue. The more muscle tissue you carry. The faster you metabolise calories.