The name comes from the fact that these muscles are commonly emphasized using a weight or resistance training routine in order to look good in a situation where a shirt is not required or a bathing suit is worn, such as at the beach. In order to judge the development of these muscles, a person will need to observe him or herself in a mirror. However, by observing in a mirror, the person is unable to view the muscles of the back of his or her body and, as such, frequently either under-emphasize or forego the training of these muscles.