This chapter analyzes the integration of health variables into contemporary Physical Education, with a focus on physical literacy and students’ holistic well-being. It examines the shift from subjective methods to objective measurement technologies, such as accelerometers, heart rate (HR) monitors, and positioning systems, which act as precise educational biomarkers. The text emphasizes the importance of physical health as a biological basis for cognitive development and academic performance and explores the link between aerobic capacity and brain plasticity. Furthermore, it provides an interpretative framework for key variables such as moderate-to-vigorous physical activity (MVPA), sedentary time, and HR, emphasizing their pedagogical value in workload management and fostering autonomy. The teacher’s role in bridging the gap between technological data and students’ health literacy is also discussed, as is the transformation of figures into practical knowledge. Finally, it discusses practical applications such as session monitoring, motivational feedback, and the ethical considerations necessary for the equitable use of wearables. This work guides researchers and teachers toward critically using technology to optimize health in school settings.