No person shall hold himself out as an athletic trainer or perform, for compensation, any of the activities of an athletic trainer, as defined in this chapter, without first obtaining a license under this chapter; provided, however, that nothing in this chapter shall be construed to prevent any person from serving as a student-trainer, assistant-trainer, teacher-trainer, or any similar position if such service is not primarily for compensation and is carried out under the supervision of a coach, physician, or a licensed athletic trainer.