In the social transition between childhood and adolescence, boys draw on discourses of masculinity that address the male body in constituting themselves as adolescents. They make themselves as no longer children and acquire a sense of themselves as adolescents by performing bodily practices that position them within some of these discourses. Repeated personal interviews conducted during the course of several years with 14 boys from an inner city area of Oslo provide the data for analysing the way the becoming as an adolescent boy affects possible and impossible ways of becoming an adolescent male. Some boys enacted the strong body discourse while exercising in the gym, others did so through improving their technical skills in competitive sports, and still others did so in aiming to achieve a body that was able to defend itself when encountering trouble in the city centre. In positioning themselves within discourses of masculinity that address the male body, and performing practices that constitute them within some of these, the boys were able to produce masculinities that could be valued and challenged in contexts such as schools.