The study addressed a pressing public health problem. Globally, only 27 to 33 percent of children and adolescents meet the recommendation of at least one hour of moderate-to-vigorous physical activity per day, and Hong Kong fares worse, with just 20 to 26 percent of children aged 5 to 17 reaching that threshold. Among children aged five and under, fewer than 30 percent meet the recommended three hours of daily physical activity, of which at least one hour should be moderately vigorous. These figures matter because physical inactivity in early life is associated with elevated risks of obesity, poorer cardiometabolic health and weaker motor and cognitive development. Because health behaviours formed in early childhood tend to track through adolescence and into adulthood, and because physical activity tends to decline as children move through primary school, the early years represent a critical window for intervention — one that, once missed, becomes progressively harder to reopen.

The World Health Organization launched guidelines on physical activity, sedentary behaviour and sleep for children under five in 2019, concluding that optimal combinations of these movement behaviours reduce risks of adiposity and injury while supporting motor, cognitive, cardiometabolic, skeletal and psychosocial development. The guidelines marked a shift in thinking: rather than treating activity, sitting and sleep as separate concerns, they framed the whole 24-hour day as an integrated pattern of movement behaviours that jointly shape health. Hong Kong’s health authorities adopted these guidelines but modified them to suit the local context, applying them to children aged two to six. Adoption alone, however, is not enough: guidelines must be deliberately and strategically disseminated so that parents and teachers understand them and are equipped with practical strategies for behaviour change. Implementation science has repeatedly shown that a document published on a government website does little on its own; the challenge lies in translating its recommendations into the everyday decisions of the adults who structure children’s days.

The research team, led by Catherine Capio and colleagues, built their dissemination strategy on formative work showing that Hong Kong parents had limited awareness of the guidelines while teachers were aware but often held inaccurate knowledge of the specifics. Stakeholders had also flagged space limitations, time constraints and the high social priority placed on academic achievement as likely obstacles — concerns that resonate with the lived realities of many Hong Kong families, who often occupy compact flats and enrol children in intensive early academic preparation. Drawing on successful dissemination work in South Africa and on the Expert Recommendations for Implementing Change framework, the team designed a three-pronged approach: two-hour in-person workshops delivered separately for parents and teachers at each kindergarten; printed booklets, posters and flyers summarising the guidelines; and weekly practical tips shared through WhatsApp groups over the course of the 2021–2022 school year. All content covered the specifications and rationale behind the guidelines, the benefits of meeting each one, and concrete strategies tailored to classrooms and homes. The choice of WhatsApp was deliberate in a setting where the platform is near-universal, allowing the team to deliver small, actionable nudges at low cost rather than relying on one-off contact.

To evaluate the effort, the researchers used the RE-AIM framework, which examines Reach, Effectiveness, Adoption, Implementation and Maintenance. The framework is widely used in implementation research precisely because it forces evaluators to look beyond average effects and ask who was reached, how faithfully a programme was delivered, and whether gains persist. Eight kindergartens from districts with middle socioeconomic backgrounds received the full dissemination package, while six comparable kindergartens served as a comparison group, participating only in outcome measurement before receiving workshops afterwards. The evaluation used a mixed-methods triangulation design, combining workshop audits, online surveys, focus groups conducted over Zoom, and device-based physical activity monitoring using validated pedometers worn by children for seven days. This combination allowed the team to capture both the measurable outcomes of the programme and the contextual detail that explains them.

The reach of the programme was substantial. Seventeen workshops were held — eight for parents and nine for teachers — attended by 158 parents and 91 teachers, each of whom received printed resource materials. Of the 199 participants who completed the audit questionnaire, 92 percent provided contact details to join the WhatsApp messaging groups, an uptake rate that suggests the messaging component reached well beyond the workshop rooms. Participants rated the workshops highly, with parents scoring the informative value at 6.25 out of 7 and teachers at 5.92. Ratings of the social media content’s helpfulness and usefulness were similarly positive for both groups, indicating that the sustained drip of weekly tips was not merely tolerated but valued.

The process evaluation also surfaced the conditions that helped or hindered implementation. Teachers reported that understanding the rationale behind the guidelines led them to prioritise and integrate movement into teaching — for example, through warm-up activities at the start of class, movement woven into learning themes, music and rhythm, and storytelling. Improved play areas and increased equipment such as bicycles and balls supported adoption. Siblings and friends emerged as social motivators, with siblings helping to reduce gadget-related sedentary time and friends encouraging outdoor play — a reminder that children’s activity levels are embedded in family and peer systems rather than resting solely on adult instruction.

The barriers, however, were more structural. Teachers described how mandated academic learning areas filled the schedule, and they felt pressure from an education system that provides clear guidelines for numeracy and language but not for physical fitness and health. Time constraints, the researchers found, were better understood not as a simple shortage of hours but as a consequence of policy expectations — a finding consistent with the examination-oriented character of many Asian education systems, where early academic achievement is often treated as the primary currency of future success. Parents, meanwhile, struggled with limited access to reliable information about community sports classes and activity clubs, and described community physical environments as inconsistent, with open spaces varying greatly even within the same districts. These barriers matter because they lie largely outside the control of individual parents and teachers; no workshop can create a playground where none exists.

The outcome evaluation told a largely encouraging story. At the end of the school year, teachers in the implementation group were significantly more likely than their comparison-group peers to hold correct knowledge of the guidelines for physical activity, sedentary behaviour and sleep, with logistic regression confirming the effect for physical activity and sleep after controlling for education and experience. Parents in the implementation group showed significantly greater awareness and knowledge across all three guideline areas, even after accounting for living space and educational attainment. Among children, 35 percent of those in implementation kindergartens met the physical activity guidelines compared with just 4 percent in comparison kindergartens, and pedometer data showed mean daily step counts of 10,204 in the implementation group versus 7,960 in the comparison group — a difference driven by weekdays rather than weekends. The weekday pattern is telling: it points to the kindergarten, not the home, as the site where the programme moved the needle, since children in both groups presumably faced similar weekend conditions. Compliance with sleep guidelines was high in both groups, and while more children in the implementation group met the sedentary behaviour guidelines, this difference was not significant once family factors were controlled, suggesting that parental education and home living space play a substantial role in sedentary time.

Six months after implementation, the majority of teachers and parents in the implementation kindergartens remained aware and knowledgeable of the guidelines, indicating that the knowledge gains were maintained over time — a crucial test, since single-dose interventions frequently show rapid decay.

The study was conducted during the COVID-19 pandemic, which shaped its course in important ways. Pandemic-related school suspensions meant that most kindergartens received only two in-person workshops instead of the planned six, and participants reported greater difficulty integrating the guidelines during suspension periods, when teachers could only provide activities for parents to deliver at home. Yet awareness and knowledge still rose, likely because social media delivery continued uninterrupted. The researchers note that the pandemic experience also demonstrated how social media can sustain engagement when in-person interaction is restricted — a lesson with ongoing relevance for programmes serving dispersed or hard-to-reach communities.

The authors are candid about limitations. The samples did not respond repeatedly across all surveys, limiting more robust statistical analysis; teacher survey and pedometer samples were relatively small and prone to type II errors; and the pandemic context may have influenced both experiences and outcomes in ways that would differ in more stable conditions. They recommend longitudinal designs with adequately powered intact samples for future work.

The implications reach beyond Hong Kong. The researchers argue that enablers and barriers to implementing movement guidelines are often rooted in policies and social expectations — in Hong Kong’s case, an academically oriented education system that leaves little room for physical health. Their findings suggest that integrating movement into academic subjects such as mathematics and language offers a practical workaround that satisfies curricular requirements while promoting healthier behaviour. They also call for sustained dissemination, greater involvement of policymakers in health and education sectors, and re-evaluation of education policies affecting young children’s health. For societies with comparable circumstances — such as Singapore, Macau or mainland China — the kindergarten-based model, combining tailored information, practical strategies and consistent social media engagement, may offer a transferable template for turning adopted guidelines into changed behaviour.