Background: The incidence of melanoma increased rapidly throughout the last decades, with overexposure to ultraviolet (UV) radiation being an established risk factor. Due to their intensive sun exposure, many student athletes (SAs) have an increased risk for skin cancer. The Clever in Sun and Shade Program (CSSP) aims at enforcing positive attitudes toward UV protection (UVP) and at supporting sports schools in establishing UVP strategies. Methods: CSSP was developed in 2019 using participatory program planning (PPP) as well as following WHO recommendations for UVP at schools. After drafting first material, within a PPP groups were conducted at a partner school (convenience sample 1) with students (n = 20), teachers (n = 5), school administration (n = 2), and coaches (n = 5). Materials were then adapted. Program acceptance and feasibility were tested at two further schools (convenience sample 2) with PPP groups of students (n = 95) and school administration (n = 2). Content analyses and descriptive statistics were conducted. Results: Less than 50% of SAs and coaches of sample 1 expressed positive attitudes toward UVP, less than 10% reported appropriate UVP behavior. By using PPP, program material was adapted to the target groups' needs, i.e., by including specific barriers and solutions. Only the most accepted video drafts were produced. The majority of SAs of sample 2 (80-86%) used predominantly positive adjectives such as "important" and "positive" to describe the completed videos and the behavior self-check poster. Conclusions: PPP process has greatly influenced concept and materials of CSSP for sports schools. Integration of future program participants has proven to be an important component in creating a fitting and feasible program. CSSP for sports schools is a program free of charge that enables sports schools to integrate UVP into their daily routine. It will be disseminated in cooperation with German Olympic Sports Confederation and German Cancer Aid in 2021.

Skin cancer is one of the most common types of cancer and UV radiation is one of the main risk factors. Therefore, sun protection, especially in childhood, is strongly recommended. We examined the effectiveness of the ‘Clever in Sun and Shade for Preschools’ program (CLEVER) in promoting sun protection behavior among preschool staff (trial registration: DRKS00023468) and describe its dissemination. Within a cluster randomized trial with 24 preschools (n = 273 staff members) stating a high need for sun protection measures, an educational workshop for preschool staff and a project kit with materials applicable in preschool groups was provided. Staff members of preschools taking part in CLEVER report significantly stronger sun protection behavior to avoid the sun (effect size [ES] 0.70, 95% confidence interval [CI] 0.04 0.71, p < 0.05) and less perceived impediments to avoid the sun (ES −0.56, CI −0.82 −0.17, p < 0.01) after 12 months as well as higher self-efficacy to avoid the sun (ES 1.09, CI 0.39 1.07, p < 0.001) and to use sunscreen (ES 0.71, CI 0.03 0.88, p < 0.05) after 1 month. Compared to the control group, there was no significant effect on sunscreen use and further psychosocial outcomes. The effectiveness of CLEVER may be underrated due to a high drop-out rate. Within three years, an enhanced free-of-charge program kit, including a media-based workshop and materials, had reached over 4000 preschools, i.e., 7.1% of all daycare centers in Germany. The results show that CLEVER can strengthen sun protection, offer high-quality information at low cost, and is easily disseminable.