Is the type of school uniform related with physical activity levels and physical fitness in schoolchildren? A systematic review including 1,098,972 children and adolescents

Jorge Olivares-Arancibia^1,2Arturo Prat-Lopicich³Rodrigo Yáñez-Sepúlveda⁴Joaquín González⁵Boryi Alexander Becerra-Patiño⁶Júlio Brugnara Mello⁷Javier Sanchez-Martinez⁸Paulo Henrique Guerra⁹José Francisco López-Gil^10*Anelise Reis Gaya¹¹

• ¹Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
• ²Universidad de Las Américas, Santiago, Chile
• ³Metropolitan University of Educational Sciences, Ñuñoa, Santiago Metropolitan Region (RM), Chile
• ⁴Andres Bello University, Santiago, Santiago Metropolitan Region (RM), Chile
• ⁵University of La Serena, La Serena, IV Coquimbo Region, Chile
• ⁶National Pedagogic University, Bogotá, Cundinamarca, Colombia
• ⁷Pontificia Universidad Católica de Valparaíso, Valparaiso, V Valparaíso Region, Chile
• ⁸University of Granada, Granada, Spain
• ⁹Universidade Estadual Paulista, Sao Paulo, Brazil
• ¹⁰University of the Americas, Quito, Pichincha, Ecuador
• ¹¹Federal University of Pelotas, Pelotas, Rio Grande do Sul, Brazil

Introduction: School uniforms play a crucial role in promoting physical activity among children and adolescents during school hours. This increased activity can help reduce the risk of metabolic and noncommunicable diseases, with physical inactivity and a sedentary lifestyle acting as mediators in the development of these conditions. This systematic review aimed to explore the differences in physical activity levels and physical fitness based on the type of uniform worn by schoolchildren. Materials and Methods: The search strategy was performed in eight databases—PubMed, Web of Science, SPORTDiscus, ScienceDirect, Embase, CINAHL, Scopus, and LILACS—following PRISMA guidelines. They were selected on the basis of the following criteria: they were children and adolescents in school and used traditional schools or sports uniforms with their levels of physical activity and physical condition. Additionally, a manual search was performed on Google Scholar to include gray literature. Results: From 1,703 initially identified studies, five studies met inclusion criteria. Sports uniforms were consistently associated with higher physical activity levels compared to traditional uniforms, with girls showing 14.5 additional minutes of playtime and significantly greater activity during recess and lunch periods (p<0.05). Two studies demonstrated improved cardiorespiratory and muscular fitness indicators in adolescents wearing sports uniforms. Population-level data from 135 countries confirmed these individual-level findings, showing reduced physical activity compliance in countries with mandatory traditional uniform policies. Conclusions: The available scientific evidence suggests that sports uniforms facilitate higher levels of physical activity, increased playtime, and improved physical fitness indicators among school-aged children and adolescents, with particularly pronounced benefits for girls. Schools should consider adopting more flexible uniform policies that prioritize comfort and movement to support students' overall health outcomes.