Chin-up bar exercises are said to be the best strength training exercises for the upper body to build muscle mass. If you are a beginner, chances are high that you will be able to do only 1 to 5 chin-ups. To do this exercise, you will require a simple piece of equipment, i.e., the chin-up bar. When you have a bar put up in your house, you will have to place it at a height, which will require you to jump up to grab the bar, while your feet should hang free. Muscles worked by doing this exercise include the upper body, shoulder, and forearms.