I just found out females have a hymen? does it break? is it painful? when having sex? losing virginity? while exercising? i don't understand..

Many questions: The vagina starts (ends) in a thin wall of tissue that usually has a central opening 1/4-1/2 inch in diameter to allow menstrual flow. Like most tissues,it has nerve endings, and tearing it with sex or a sex toy will produce transient discomfort and bleeding. In some,the hymen never forms or is lost in non sexual events in childhood. Exercise doesn't effect it. Penetration does.