Muscles that are gained through working out in a gym and may make a man look strong, but in reality they are gained just for show, like on a beach (hence the name), and therefore are not indicative of toughness or fortitude.
Mike "The Situation" has beach muscles. He looks strong but if he ever got in a fight with someone who was actually tough he would get his ass beat because he only has Beach Muscles.
by JimboD October 16, 2010