No business regulation certificate or permit provided for in this chapter is required for hospitals, nursing homes or sanitariums or for a person holding an unrevoked certificate to practice medicine under the laws of the state or a person working under the personal direction of any person or in any establishment. Further, this chapter does not apply to barbers or cosmetologists lawfully carrying out their professions, and holding a valid unrevoked license or certificate or registration issued by the state, or to participants in any professional or amateur sports competition.