Although any static bar is a potential pull up bar, there are bars which have been especially made for the purpose and now some of those bars are designed so that they may be used in your home, saving you the problem of joining a gym. Some of these bars are designed as a free standing pull-up bar whilst others include doorway pull up bars and wall mounted pull up bars but all can be installed in your home for ease and convenience.
Some people may be wondering why anyone would want a pull up bar in their home but the reasons are simple. First pull ups are considered to be compound exercises which mean they target several muscle groups and not just one. Secondly, gymnasium fees can be expensive even if you do not use or want to use some of the more complex and expensive equipment. Thirdly, if you do intend to do exercises, it is easier to find the time if you do them at home and that in turn gives you less excuses for not keeping to a program you have decided on trying to keep up.
Sit ups are also considered to be a compound exercise but instead of targeting the upper body muscle groups which pull ups do, they target the lower body muscle groups. Sit ups also require no expensive equipment if any at all and so both these exercises can be done in the home and as they are both compound exercises, they may be all the exercise many people need as they are very beneficial.
Of course though there are times when specific exercises are recommended and these two are not them but, even in those instances these two exercises can be beneficial as they increase the heart rate which in turn can make other exercises easier. One example of this is when someone wishes to use exercise in order to lose weight. Neither of these exercises is particularly known as exercises to help weight loss but most people that do exercise routines in order to try and lose weight, do include these in their routines and when they do, a higher success rate is the result.
Although pull ups will always target specific upper body muscle groups, if there are certain upper body muscle groups which needs special attention, the grip on the bar can be altered to make that possible. A grip with hands wide apart will target a different muscle group than would be targeted if the hands gripped the bar close together. Another grip which can better target a specific muscle group and is often called a chin up, is when the hands reverse their grip on the bar.
Pull ups especially known though for allowing those that keep them up to achieve a V shaped upper body and many just start with one or two pull ups and then gradually increase that number as time goes on but even just one or two pull ups can have benefits on their own.