Now in its sixth year of implementation, the TECHFIT approach involves having individuals and teams of middle school teachers successfully complete a week-long, professional development (PD) workshop through which they acquire the essential skills that contribute to the task of innovating an exergame. An exergame is a technology-supported fitness game that can educate/train, assess performance, and/or entertain the player(s). Teachers demonstrate their understanding of concepts and tools taught in the PD by implementing their own functional exergame invention by the fifth day. Then, during the subsequent school year, the teachers teach the same skills they learned in the PD, so their students can innovate their own exergames. Successful completion of the curriculum addresses the majority of standards for technological and engineering literacy identified by the International Technology and Engineering Educators Association (ITEEA, 2020). This article will walk the reader through the process of creating an exergame that will employ externally wired input and output components. Although specific tools are used in the TECHFIT curriculum, the approach and process should be applicable to other tools.