Many high school students withdraw from physical education (PE) and sport science majors (including biomechanics) due to anxiety about science and mathematics. In some situations, it is not necessarily what STEM subject is taught but how it is introduced and what pedagogy is applied by the teacher. In high school, students who study PE are often required to understand basic biomechanical principles. Initial research supports the positive effects that action-based and game-based pedagogy has on students' attitudes toward the field of biomechanics; however, quantitative evidence remains sparse. This is particularly true when wider STEM integration is considered. The purpose of this study was to quantify high school students' (n = 14) perceptions toward biomechanics after participating in a Fitness Integrated with Technology (F.I.T) and a tactical games approach (TGA) over 16 lessons (eight weeks in total). Professional development workshops were used to help the teacher develop pedagogical content knowledge to teach biomechanics using the F.I.T and TGA approach. As a primary outcome measure, the Student Assessment of Learning Gains (SALG) instrument was used pre and post the F.I.T. theoretical and practical lessons while variables including the feasibility, practicality, and challenges of applying F.I.T. was used as a secondary measure. This was applied to better understand the impact of using F.I.T and TGA to teach an integrated STEM and biomechanics subject. SALG scores exhibited a significant difference pre and post the F.I.T approach (p < 0.001) with the biggest changes seen in the "excellent learning gain" category post the F.I.T. implementation (t = -2.26, p = 0.0019) demonstrating that students felt they had made satisfactory to very good learning gains by the end of the final lesson. These findings further support the ability for F.I.T and TGA approaches to positively impact students' perceptions toward biomechanics and STEM, although opportunities persist to increase student career interest in both STEM, PE and biomechanics. This case report presents and discusses the study's results, interpretations, limitations, and implications for future research on integrated biomechanics and STEM outreach activities.