A human body has the ability to release a huge amount of strength through its muscles. The reason that a person is unable to unlock all of this strength at any given time is so that muscles do not get strained or torn in the process. This is a cool safety feature of the body so that people do not over exert themselves and end up crashing. In order to produce large amounts of strength it takes a lot of energy and using muscles to their max for a long period of time can be very harmful to the body. However, in some cases when on an adrenaline rush people are able to tap into this strength in order to do things that seem to be humanly impossible. There have been incidents were people have lifted cars or moved heavy objects in order to save or do something. This shows just goes to shows how powerful the human body is.