The FITeens project aimed to pilot an engaging and sustainable educational intervention utilizing mobile devices, targeting adolescents to foster adherence to various health-related behaviors known as the big-6 (i.e., physical activity, screen time and sedentary behavior, sleep duration, Mediterranean diet, alcohol, and tobacco). The objectives included: a) Raising awareness about the significance of physical activity and other health-related behaviors. b) Assisting Physical Education teachers in acquiring comprehensive knowledge on developing online lessons and engaging students in physical activity and other health-related behaviors, offering practical examples. c) Encouraging the daily practice of physical activity and enhancing adolescents' understanding of its importance and other healthy habits d) Creating an entertaining and interactive mobile application using gamification techniques to motivate teenagers to engage in physical activity.
High levels of physical activity (PA) (Poitras et al., 2016), limited screen time and sedentary behavior (Carson et al., 2016), optimal sleep duration (Chaput et al., 2016), and adherence to a Mediterranean diet (Diolintzi et al., 2019) are associated with various benefits in young people, while tobacco and alcohol consumption have negative consequences (Gobbi et al., 2019). Despite this knowledge, many adolescents fail to meet recommendations for PA (Guthold et al., 2020), screen time (Thomas et al., 2019), sleep duration (Galland et al., 2018), and diet (Idelson et al., 2017). Additionally, high rates of alcohol and tobacco use among youth have been reported (Halladay et al., 2020). Schools are optimal environments for implementing interventions targeting these behaviors (Sevil et al., 2019). Moreover, eHealth interventions offer enhanced engagement, fidelity, and scalability (Champion et al., 2019). However, ensuring the sustainability of these interventions relies on schools nurturing knowledgeable senior leaders capable of navigating changing circumstances (Herlitz et al., 2020). Therefore, there is a pressing need for teacher training in health education to enhance the success of school-based interventions.