Physical activity is essential for children’s and adolescents’ physical and mental health, wellbeing, learning, and development. Yet globally most young people do not meet the recommended average of at least 60 minutes of moderate‑to‑vigorous physical activity a day, with even lower levels among girls and young people from disadvantaged backgrounds. This blog explores reasons why so many children struggle to meet physical activity guidelines and highlights growing evidence that system‑level change, rather than individual behaviour change alone, is needed to help young people live active lives. Physical activity behaviours in adolescence: current evidence and opportunities for intervention – The Lancet
Schools play a central role in young people’s opportunities for physical activity. They provide multiple daily opportunities for movement, from active travel and break time play to sport, PE, and informal activity. Yet school environments, routines, and expectations unintentionally restrict movement. Research shows that school‑based interventions improve physical activity only modestly and effects often fade beyond six months, suggesting that contextual factors limit sustained behavioural change. Frontiers | Rethinking children’s physical activity interventions at school: A new context-specific approach; Interventions for promoting physical activity among adolescents in school settings: systematic review and meta-analysis — JOGH
For years, strategies to increase young people’s physical activity have focused on changing individual behaviours, encouraging children to be more motivated, confident, or knowledgeable. But evidence consistently shows that such programmes yield only small improvements in moderate physical activity and do not reliably reduce sedentary time. Crucially, these approaches assume that young people have choice and opportunity, yet these are often constrained by factors outside their control. When school rules, clothing, space, or social norms limit movement, even highly motivated children cannot act on that motivation. Frontiers | Are school-based behavioural interventions an effective strategy for improving physical activity and sedentary behaviour in children and adolescents? A meta-analysis
School uniform is one example of a systemic barrier. Although often seen as unrelated to physical activity, uniforms are worn all day, every day, shaping comfort, movement, identity, and inclusion. International evidence shows that in contexts with more traditional or restrictive uniforms, fewer children, especially girls, meet activity guidelines. In primary schools, restrictive designs can widen gender disparities by limiting everyday active play. Among adolescents, patterns are less clear, reflecting an important evidence gap at an age when activity levels decline most rapidly. Physical activity behaviours in adolescence: current evidence and opportunities for intervention – The Lancet
Experiences from Australia show how uniform reform can support more active lifestyles. Trials where students were permitted to wear sports uniforms throughout the day have shown reductions in sedentary time and increases in light physical activity among girls, alongside strong support from students, teachers, and parents for more comfortable, practical clothing. Cluster randomised controlled trial to determine the impact of an activity enabling uniform on primary school student’s fitness and physical activity: study protocol for the Active WeAR Everyday (AWARE) study – PubMedThese findings illustrate how simple structural changes can enable movement at scale, without requiring additional lessons, equipment, or programmes. The growing interest in inclusive sportswear reflects increasing recognition that clothing matters. ‘We shouldn’t feel insecure in our school PE kit’ – BBC News Young people report that flexible, comfortable clothing helps them feel more confident being active. Focusing on PE kit is a fantastic start to this conversation, but risks missing the bigger systemic opportunity. Everyday uniform policies, skirts, formal trousers and shoes, tights, shirts, and blazers shape young people’s comfort, willingness and opportunities to move across the whole day. A whole‑uniform approach is therefore more likely to lead to lasting, meaningful change for more young people.
Why is it important?
Childhood and adolescence are critical periods for establishing lifelong health behaviours, yet these are also the phases where physical activity drops off most sharply. In today’s society, young people are spending more time than ever in sedentary pursuits, including screen-based entertainment and online socialising. At the same time, opportunities to be active are increasingly the harder choice with reduced active play, more time indoors, safety concerns, and school environments that unintentionally constrain movement all contributing to an everyday reality where it’s easier not to be active.
This is why systemic change is essential. When the environment does not support movement, expecting young people to rely on factors such as motivation, knowledge and intentions is unrealistic. Global evidence highlights the urgent need for supportive systems to enable children to be active throughout the day. Reviews show that school‑based interventions are most effective when they involve multi-component, system‑level strategies, rather than volitional‑focused individual level approaches. [bjsm.bmj.com] In other words: we need to make physical activity the easy, obvious, accessible choice, not an extra effort.
Uniform reform is a practical, equitable, and scalable strategy that can help achieve this. Flexible, comfortable, movement friendly uniforms can reduce gender disparities, normalise daily movement, and remove barriers related to comfort, identity, body image, and changing in front of peers. Because uniforms are universal part of school life, changes have the potential to reach all students, not only those already confident or motivated to be active. Evidence from students, teachers, and parents shows broad support for more active uniform policies, demonstrating that this is both a feasible and welcome shift within schools. Active School Uniforms – Youth Sport Trust
As the evidence shows, supporting young people to move more requires changing the systems around them, not relying on individual motivation in environments that restrict choice, opportunity, and comfort. If we want children to be active, we must create systems with activity at the heart.
Take Home Messages
- Most young people do not meet physical activity guidelines, with girls particularly affected.
- Behaviour‑change programmes targeting individual level factors such as knowledge and motivation aren’t enough; lasting impact requires system‑wide changes that remove everyday barriers.
- Rethinking whole‑school uniform policies can support daily movement and promote greater inclusion and equity.
Reader in Behavioural Epidemiology and Public Health
This blog was originally published by ISPAH for World Physical Activity Day 2026. Read the original article.