As people decide to workout, their body will be changing. It may be getting smaller because of the exercises that they are doing, but they also may be gaining muscle in different parts of the body. However, people may get tired of doing exercises because it gets boring. It is the same routine over and over again.
The body will also get tired of doing the same routine and the muscles will stop growing and the body will stop responding to the workout. Therefore, the workout routine should be changed. There is not a specific amount of times the workout should be done before it is changed. The workout should be changed if you are not getting the results that you need to get.