The stakes are surprisingly high for such a young age group. International guidelines recommend that toddlers accumulate at least 180 minutes of physical activity per day, including structured activity, while limiting restraint and screen time and securing 11 to 14 hours of good-quality sleep within every 24-hour period. Yet the evidence suggests most toddlers fall dramatically short. In an Australian study cited by the research team, fewer than 9 percent of toddlers met the full suite of national 24-hour movement guidelines for the early years. While 96.5 percent met the physical activity target and 79.7 percent met the sleep target, a mere 11.4 percent stayed within recommended sedentary screen time limits. Data from Singapore tell a similar story: around 82 percent of toddlers met sleep recommendations, but only about half met physical activity guidelines and fewer than 39 percent stayed within screen time limits. Canadian studies echo the pattern, with adherence to sleep and activity guidelines generally high but the majority of two-year-olds exceeding screen time recommendations.

Why does this matter so much? Because the early years are a period of extraordinary neural plasticity, when the foundations of motor competence, cognition, and emotional regulation are laid down. Research shows that toddlers’ gross motor skills are positively associated with cognitive development, and that shorter naps combined with a higher proportion of nighttime sleep correlate with better cognitive outcomes. Conversely, the prevalence of below-average motor skills in young children appears to be higher than normative samples would predict—a red flag that targeted developmental programmes can potentially address, since studies have shown such programmes can improve gross motor skills in toddlers. Music, meanwhile, is far more than entertainment at this age. When caregivers receive music training, children in their care show increased visual, vocal, and physical engagement, and music training in kindergartens has been shown to improve inhibitory control, a core executive function. Musical workshops built around sound-producing objects have been found to enhance toddlers’ natural exploratory drive.

Despite this converging evidence, no study to date has evaluated a holistic programme in early childhood education and care settings that integrates physical activity, sedentary behaviour, sleep, and motor and musical skills simultaneously. That gap is what MoviMusi is designed to fill. The trial will run over 24 months in the capital cities of three Spanish regions—Valencia, Murcia, and Toledo—chosen because they reflect the diversity of the Spanish educational system. In total, 24 public early childhood education and care centres will participate, split evenly between an intervention group and a control group: five centres per arm in Valencia, four per arm in Murcia, and three per arm in Toledo. With an average class size of 13 toddlers, this translates to roughly 312 children, distributed as 130 toddlers in Valencia, 104 in Murcia, and 78 in Toledo.

The trial’s design reflects the statistical realities of studying children in group settings. Because children within the same classroom behave more similarly to one another than to children in other classrooms—an effect quantified by an intraclass correlation—the researchers used cluster-randomisation formulas to calculate their sample. They powered the study to detect an expected increase of 8 minutes of moderate-to-vigorous physical activity per school day, building on their own previous accelerometry work showing that children aged two to three accumulate about 40 minutes of such activity during childcare hours. With a significance level of 5 percent, 90 percent statistical power, and an intraclass correlation of 0.35, 24 centres emerged as the required sample. Randomisation will occur only after baseline measurements are complete, at the end of the first year, performed by an independent researcher using a computer-generated sequence—a blinded procedure that protects against allocation bias.

What makes MoviMusi genuinely distinctive is its participatory philosophy. Rather than imposing a rigid, top-down curriculum, the researchers will work with each intervention centre’s principals, educators, and families to co-design a programme tailored to that centre’s specific realities. Previous research suggests these horizontal, dialogic interventions are more effective at changing school culture around physical activity than vertical, prescriptive ones. The programme unfolds along three axes. First, training: educators and families attend seminars and workshops on promoting physical activity as healthy behaviour and using music as a didactic resource. Second, participation: over two months, each institution designs its own movement and music programme, supported by baseline data on the personal, social, and environmental correlates of the children’s movement behaviours. Third, implementation: the specific actions run for six months, after which the team evaluates effectiveness against the control group, whose centres continue their usual curriculum.

The measurement toolkit is remarkably comprehensive for a population so young. Children will wear ActiGraph wGT3X-BT accelerometers on their right hip for one full week, from waking to bedtime, with data processed in 15-second epochs and scored using validated cutoffs for two-year-olds. Sleep will be captured through the Spanish-adapted Brief Infant Sleep Questionnaire, supplemented by teacher-recorded nap times during school hours. Motor skills will be assessed with the Peabody Developmental Motor Scales, third edition, a standardised instrument validated for Spanish children from six months to five years. Musical skills will be measured with MUSKITO—a new scale the research team itself is developing—covering listening, singing, instrumental interpretation, improvisation or composition, and movement. Direct observation during unstructured outdoor play will use a modified version of the OSRAC-P system, in which trained coders record a child’s activity state every 25 seconds in five-second observation windows, with intercoder reliability verified using Cohen’s kappa.

Beyond the child-level outcomes, the study casts a wide net across the entire educational ecosystem. Researchers will assess the quality of each centre using the Infant/Toddler Environment Rating Scale, measure playground area and density using satellite imagery and geographic information systems, and classify playgrounds as low or high density based on free space per child. Parents will complete validated questionnaires on their children’s after-hours activity, screen time, and modes of transport to school, alongside a dedicated scale measuring barriers to active commuting. Focus groups with educators and families, conducted at baseline and after implementation, will probe perceptions of barriers and facilitators to embedding movement and music in daily practice. The team will even analyse official curriculum documents to understand how public authorities promote—or fail to promote—movement and music in early childhood education, and will invite education authorities to result-dissemination meetings.

The researchers are candid about the challenges ahead. Interventions must respect each centre’s internal culture rather than dictate activities; family engagement with questionnaires cannot be taken for granted; accelerometer data will inevitably be lost to the absences that are common in toddler classrooms; and coordinating a project across three cities with different administrative rhythms demands dedicated local leads. The statistical plan anticipates these realities, using mixed-effects longitudinal models that adjust for baseline values, age, sex, and body mass index, with random effects for cities, groups, and participants, and multiple imputation for missing data handled by a blinded analyst. Ethical approval has been granted by the University of Valencia’s ethics committee, and written informed consent will be required from all participating families.

If MoviMusi succeeds, the implications could ripple well beyond the 24 participating nurseries. The team plans to share results at three levels—within each centre, at public events in the three cities, and through an open conference—culminating in a set of good-practice guidelines for promoting movement and music opportunities that could inform curriculum design and teacher training nationally and internationally. The study also answers a call from leading movement-behaviour researchers, who have identified interventions for children under three as a critical frontier. In a world where toddler screen time is quietly eroding the building blocks of healthy development, the idea that songs and structured play, delivered through the everyday curriculum, could shift the trajectory of an entire generation is a proposition worth testing rigorously. MoviMusi is now positioned to deliver exactly that test.

Subject of Research: A cluster-randomised controlled trial of a movement and music programme on movement behaviours and motor and musical skills in toddlers

Article Title: Effectiveness of a movement and music programme on activity, sedentary, and sleep behaviours and motor and musical skills in young children: protocol for the MoviMusi cluster randomised controlled trial

Article References: del Mar Bernabé-Villodre, M., Martínez-Bello, V. E., Vega-Perona, H., Díaz-Barahona, J., García-Ochoa, Y. C., Molines-Borrás, S., Gértrudix-Barrio, F., Montoya-Rubio, J. C., Fernández-Vilar, M. Á., Azorín-Delegido, J. M., Filenko, N., Martínez-Rojas, Á., & Martínez-Bello, D. A. (2024). Effectiveness of a movement and music programme on activity, sedentary, and sleep behaviours and motor and musical skills in young children: protocol for the MoviMusi cluster randomised controlled trial. Journal of Activity, Sedentary and Sleep Behaviors, 3(1), Article 28. https://doi.org/10.1186/s44167-024-00065-5

Image Credits: AI Generated

DOI: 10.1186/s44167-024-00065-5

Keywords: early childhood education, physical activity, sedentary behaviour, sleep, motor skills, musical skills, cluster randomised controlled trial, toddlers, MoviMusi, accelerometry, 24-hour movement guidelines, Spain

The study, published in the Journal of Activity, Sedentary and Sleep Behaviors by researchers at Stanford University School of Medicine, drew on four consecutive cycles of the National Health and Nutrition Examination Survey (NHANES) collected between 2011 and 2018. From that continuous national monitoring program, the team assembled an analytic sample of 2,812 adults aged 65 and older, the fastest-growing demographic in the country, now numbering nearly 62 million and projected to reach 84 million by 2054.

The guidelines at the heart of the study were developed by the Canadian Society for Exercise Physiology and adapted for adults 65 and older. They specify three thresholds: seven to eight hours of sleep per night, at least 150 minutes per week of moderate-to-vigorous physical activity (MVPA), and less than eight hours per day of sedentary behavior. Participants self-reported their sleep duration and their sitting time, while MVPA was estimated using the validated Global Physical Activity Questionnaire, which captures occupational, transportation, and leisure-time activity. In line with US national physical activity guidelines, one minute of vigorous activity was counted as two minutes of moderate activity when tallying weekly totals.

Depression was screened using the Patient Health Questionnaire-9, or PHQ-9, a nine-item instrument based on diagnostic criteria for major depressive disorder. Each item rates the frequency of a depressive symptom over the previous two weeks on a scale from zero to three, producing a total score from 0 to 27. A score of 10 or greater was used to classify a participant as depressed. The researchers then used logistic regression, adjusted for age, sex, race and ethnicity, poverty income ratio, marital status, education, smoking history, and body mass index, to estimate the odds of depression associated with failing to meet the guidelines, alone and in every combination. Survey weights were applied throughout to reflect the US population.

The headline finding was clear: compared with older adults who met all three guidelines, those who met none had 1.7 times higher odds of depression after adjustment. Only 12.5 percent of participants with depression adhered to all three movement behavior guidelines, versus 20.4 percent of those without depression. Conversely, 13.2 percent of those with depression failed to meet any of the three guidelines, compared with just 4.9 percent of those without depression. When the researchers examined pairs of behaviors, non-adherence to the combined sedentary behavior and sleep guidelines was associated with 1.8 times higher odds of depression, and non-adherence to the combined sleep and MVPA guidelines with 1.9 times higher odds.

The most striking single-behavior result concerned sleep. Older adults who did not get seven to eight hours of sleep per night had 2.1 times higher odds of depression than those who did, a highly significant association. By contrast, failing to meet the sedentary behavior or MVPA guidelines alone was not significantly linked to depression in the full sample. This suggests that physical activity and reduced sitting may only confer measurable mental health protection when sleep duration is also adequate, a pattern the authors describe as pointing to sleep as a potential cornerstone of the movement behavior triad in later life.

When the analysis was stratified by sex, most of these associations survived only among men. Older males who met none of the three guidelines had 2.5 times higher odds of depression than those who met all three, while the equivalent estimate for women was statistically indistinguishable from no association. Non-adherence to the combined sedentary and sleep guidelines was linked to 2.1 times higher odds in men, and non-adherence to the combined sleep and MVPA guidelines to 2.7 times higher odds, with neither reaching significance in women. Notably, the sleep guideline itself remained significant for both sexes, with roughly twofold higher odds of depression among non-adherent men and women alike, suggesting that adequate sleep matters for everyone while the compound effects of the full guideline package may be sex-specific.

One unexpected result deserves attention: among older women, meeting the combined sedentary behavior and MVPA guidelines was marginally associated with lower odds of depression in the non-adherent group, meaning that adherence appeared tentatively linked to higher odds. The authors caution against over-interpreting this finding, but they offer several plausible explanations. Older women may accumulate their activity through caregiving or occupational demands rather than enjoyable leisure pursuits, which research suggests confer weaker psychological benefits. Sedentary time, too, differs in quality: hours spent relaxing are not the same as hours spent under the strain of caregiving. Biological and psychosocial stressors specific to older women, along with residual confounding by social roles, could also shape the relationship in ways that crude guideline thresholds cannot capture.

Why might men be more vulnerable to the mental health consequences of falling short on the full movement package? The authors point to possible sex differences in physiological stress responses, including altered hypothalamic-pituitary-adrenal axis activity and inflammatory processes that have been implicated in depression risk. Men may also possess fewer protective psychosocial resources, such as strong social support networks, to buffer the impact of reduced activity, and they may rely more heavily on physical activity as a coping mechanism for stress. If movement disappears from a man’s daily routine, the psychological scaffolding it provides may collapse with it.

The study has limitations that temper causal claims. Its cross-sectional design cannot establish whether movement behaviors predict depression or whether depression drives people to sleep poorly, sit more, and move less. All behaviors and depression status were self-reported, and unmeasured confounders such as sleep medication use, chronic illness, and medical history could influence the results. The binary adherence thresholds also raise a subtle measurement issue: an older adult logging 149 minutes of weekly activity is classified as non-adherent despite being functionally indistinguishable from someone at 151 minutes. Still, the nationally representative, racially diverse sample and the comprehensive treatment of all three behaviors give the findings considerable weight. For clinicians and public health planners, the message is provocative: interventions promoting physical activity in older adults may work best when paired with non-pharmacological sleep support, and older men in particular may benefit from programs that target movement, sitting, and sleep simultaneously rather than one behavior at a time.

Subject of Research: Associations between adherence to 24-hour movement behavior guidelines and depression risk in older US adults

Article Title: Adherence to the 24-hour movement behavior guidelines and depression risk among older adults from the United States

Article References: Adherence to the 24-hour movement behavior guidelines and depression risk among older adults from the United States. (n.d.). https://doi.org/10.1186/s44167-024-00071-7

Image Credits: AI Generated

DOI: 10.1186/s44167-024-00071-7

Keywords: older adults, depression, 24-hour movement behavior, sleep duration, sedentary behavior, physical activity, MVPA, NHANES, sex differences, mental health, PHQ-9, aging

The PLAYCE cohort was established to address a fundamental gap in child health research. Childhood is a critical period for establishing movement behaviours, including regular physical activity, adequate sleep and limited sedentary time, and these behaviours provide the foundation for lifelong health. They influence weight status, cardiorespiratory fitness, the musculoskeletal system, and cognitive and psychosocial development. Yet most research on children’s movement behaviours has been cross-sectional, capturing a single moment in time rather than tracking how behaviours change and interact as children grow. Australia and Canada were the first countries to release integrated 24-hour movement guidelines for young children in 2018, treating physical activity, sedentary behaviour and sleep as three co-dependent behaviours rather than isolated targets. Meeting all three recommendations together is considered optimal for child health, but until now it has been unclear whether children who achieve this balance in their early years sustain it as they move into middle childhood, or what that trajectory means for their health and development.

The scale of the measurement challenge is considerable. Between April 2015 and April 2018, researchers recruited 1,918 children aged 2 to 5 years through early childhood education and care services across Perth, Western Australia. Services were randomly sampled and evenly distributed across low, medium and high socio-economic areas and across service sizes. Of 273 services invited, 126 directors consented, a response rate of 46.2 percent. At the first wave, the median age of participating children was 3.3 years and 53 percent were male. The cohort has since been followed through junior primary school at ages 5 to 7, middle childhood at ages 8 to 10, and a fourth wave of data collection at ages 11 to 13 is underway and expected to be completed in early 2026. In total, 434 children have participated at all three completed waves, providing the kind of sustained individual tracking that longitudinal behavioural science depends on.

The technical core of the study is its use of ActiGraph GT3X+ accelerometers, small devices worn on the right hip that record acceleration in three dimensions. Children wore the devices for seven consecutive days, initially excluding water activities and sleep, and from the second wave onward across the full 24-hour cycle to capture sleep as well as waking movement. Valid wear time was defined as a minimum of eight hours on at least three weekdays and one weekend day. Rather than relying on traditional cut-point methods, which classify activity intensity using fixed thresholds, the researchers applied a random forest machine learning model to the raw tri-axial acceleration signals. This algorithm classifies behaviour into sedentary activity, light-intensity games, walking, running and moderate-to-vigorous activity with an overall accuracy exceeding 80 percent, agreeing more closely with measured intensity than cut-point approaches and showing equivalence with direct observation. The distinction matters because young children’s activity is notoriously sporadic and difficult to categorise, and more accurate classification yields a sharper picture of the actual doses and combinations of movement linked to health outcomes.

The environmental measurement is equally ambitious. A subset of 237 children at the first wave also wore Qstarz GPS devices on the same belt as their accelerometers, recording location coordinates, distance, speed and elevation with a median dynamic accuracy of 2.9 metres. Combining these spatial traces with Geographic Information Systems data allowed researchers to calculate measures around each child’s home and care centre, including outdoor space, vegetation, public open space quality, blue space, traffic exposure, public transport, street connectivity, residential density and access to child-relevant services, all within 500-metre and 1,600-metre buffers. Physical and policy audits of early childhood education and care centres assessed indoor and outdoor play spaces, play and media equipment, built and natural features, and the presence of service policies on physical activity, screen time and sun protection. Educator surveys captured staff practices, and parent surveys recorded structured and unstructured activity, sleep, screen time, diet, social-emotional development measured with the Strengths and Difficulties Questionnaire, motor development, and neighbourhood perceptions using the Neighbourhood Walkability Scale for Youth.

The baseline results are striking. On average, preschoolers in the cohort accumulated 373 minutes of total physical activity per day, of which just 39.1 minutes was energetic play such as running and vigorous games. They averaged 106.9 minutes of daily screen time and 11.5 hours of sleep. Individually, 42 percent met the physical activity guideline, 67 percent met the screen time recommendation and 92 percent met the sleep guideline, but only 8 percent satisfied all three simultaneously. Meeting all three recommendations was positively associated with social-emotional development in boys, consistent with emerging international evidence that the combination of behaviours, not any single behaviour alone, drives developmental benefit. Other analyses from the cohort have linked moderate-to-vigorous physical activity with self-regulation and cognitive school readiness, and shown that children from dog-owning households had reduced odds of social-emotional problems, with those who walked or played with their dog more often showing improved prosocial behaviours.

The environmental findings offer concrete design clues. Features of the home yard, including its size, the presence of play equipment and natural features, were positively associated with preschoolers’ outdoor play. At childcare centres, tree canopy in outdoor areas served both as sun protection and as an enabler of children’s outdoor time, while more portable play equipment was linked to greater outdoor activity. A novel analysis combining accelerometer, GPS and on-site audit data mapped physical activity hot spots within centres, finding them concentrated in open areas and adjacent outdoor play spaces where children could move freely between them. Air pollution monitoring revealed a troubling overlap: pollution concentrations at childcare centres were highest at exactly the times children were likely to be active outdoors, prompting a recommendation to avoid locating services in high-traffic areas. Neighbourhood perceptions mattered too, with parents’ positive views of traffic safety, crime safety and land use mix associated with lower odds of social-emotional difficulties in their children.

The study has not been without challenges. Retention fell to 39.9 percent of eligible and contactable participants at wave 2 and 38.7 percent at wave 3, reflecting the three-year recruitment window that left some children outside the age criteria for follow-up, the disruption of COVID-19 restrictions during wave 2 data collection, and the time burden of parental questionnaires. The researchers note, however, that the representativeness of the sample remained largely unaffected and the cohort remains sufficiently powered for longitudinal analyses. The study is limited to a single site in Perth and underrepresents families with lower relative socio-economic status, single-parent households, First Nations families and culturally and linguistically diverse communities, gaps the team identifies as priorities for future research. A community-based consumer reference group of parents now provides input into recruitment, methodology and the translation of findings, meeting at least three times a year.

As the fourth wave concludes, the team plans traditional longitudinal and compositional analyses to map in detail how movement behaviours shift across the transition from early childhood education to full-time school, a period when previous small studies have recorded increases of around 40 minutes of daily sedentary time and declines in physical activity. Whether those changes are permanent or transitional remains unknown, and the PLAYCE data should answer it. The findings are expected to inform future revisions of national and international 24-hour Movement Guidelines, which have called for more rigorous and consistent accelerometer processing methods, and to guide setting-specific and population-level interventions, from childcare policy to neighbourhood design, aimed at curbing childhood obesity and ensuring children have the opportunity to lead active, healthy lives from their earliest years through adolescence.

Subject of Research: A longitudinal cohort study of children's physical activity, sedentary behaviour and sleep across early to middle childhood in Western Australia

Article Title: Profile of the PLAY spaces & environments for children’s physical activity, sedentary behaviour and sleep (PLAYCE) cohort study, Western Australia

Article References: Christian, H., Nathan, A., Trost, S. G., Schipperijn, J., Boruff, B., Adams, E. K., George, P., Moore, H. L., & Henry, A. (2025). Profile of the PLAY spaces & environments for children’s physical activity, sedentary behaviour and sleep (PLAYCE) cohort study, Western Australia. Journal of Activity, Sedentary and Sleep Behaviors, 4(1), Article 7. https://doi.org/10.1186/s44167-025-00078-8

Image Credits: AI Generated

DOI: 10.1186/s44167-025-00078-8

Keywords: PLAYCE cohort study, children's physical activity, sedentary behaviour, sleep, 24-hour movement guidelines, accelerometry, built environment, early childhood education, child development, obesity, GPS tracking, Western Australia

The research team, led by Hilary Caldwell and Sarah Moore of Dalhousie University alongside collaborators from the University of British Columbia, the Children’s Hospital of Eastern Ontario Research Institute, and other Canadian institutions, surveyed two large independent national samples of parents. In October 2020, 1,568 parents of children and adolescents aged 5 to 17 completed detailed online questionnaires about their own movement behaviors and those of one of their children. In April 2021, a second sample of 1,600 parents answered the same questions. Participants were recruited through the market research company Maru/Matchbox from a panel designed to mirror the Canadian census in terms of age, gender, ethnicity, geography, and socioeconomic status, giving the results an unusually strong claim to national representativeness.

The study focused on the three pillars of the Canadian 24-Hour Movement Guidelines: moderate-to-vigorous physical activity, recreational screen time, and sleep. For children, the benchmarks were at least 60 minutes of heart-pumping activity on six or seven days per week, no more than two hours of daily recreational screen time, and age-appropriate sleep of nine to eleven hours for 5-to-13-year-olds or eight to ten hours for teenagers. Parents faced their own targets: at least 150 minutes of weekly moderate-to-vigorous activity, no more than three hours of daily recreational screen time, and seven to nine hours of nightly sleep. Meeting all three simultaneously is a demanding proposition, and the data showed just how rare it was.

The headline numbers were sobering. In October 2020, only 8 percent of parents met the combined 24-hour guidelines, rising marginally to 10 percent by April 2021. Children and adolescents fared worse still: just 4 percent met all three guidelines in fall 2020, improving only to 5 percent the following spring. Individual components told a more nuanced story. Most parents met the sleep recommendation, 66 percent in October and 68 percent in April, and a slim majority stayed within screen time limits. But physical activity was the weak link for adults, with only 20 percent meeting the MVPA target in fall 2020 before a recovery to 30 percent in spring 2021. Among children and adolescents, only 17 percent met the physical activity guideline in spring 2021, while 29 percent met the screen time limit and 71 percent slept enough.

Yet the most scientifically compelling results lay in the statistical relationships between parents and children. Using Spearman correlations suited to the non-normally distributed data, the team found consistent, positive associations between parental and child behavior in both waves. In October 2020, child and parent moderate-to-vigorous physical activity correlated at r = 0.171, child and parent screen time at r = 0.255, and child and parent sleep at r = 0.124, all statistically significant. Six months later the pattern held, with correlations ranging from 0.124 to 0.204. Fisher’s Z-tests confirmed that the strength of these parent-child links barely changed between the two timepoints, despite shifting public health restrictions across Canadian provinces.

The guideline-level analysis was even more striking. When a parent met an individual guideline, the incidence of their child meeting the same guideline rose substantially, with incidence rate ratios between 1.10 and 3.06 in October 2020 and 1.19 and 2.26 in April 2021. The strongest effect appeared for the combined 24-hour guidelines: children whose parents met all three recommendations were roughly three times as likely to meet them too in fall 2020 (IRR = 3.06, 95% CI: 1.55 to 6.04) and more than twice as likely in spring 2021 (IRR = 2.26, 95% CI: 1.34 to 3.83). According to the authors, this suggests that parental modeling or co-participation across the full sweep of the day, not just in a single behavior, exerts the greatest influence on a child’s entire 24-hour activity pattern.

The theoretical backbone of the study is Bandura’s Social Cognitive Theory, which holds that health behaviors emerge from the dynamic interplay of personal, behavioral, and environmental factors. Parents act as both models and gatekeepers: they encourage, facilitate, set expectations, and remove barriers to healthy movement. Before the pandemic, Canadian survey data showed that 73 percent of parents regularly supported their children’s sleep, 49 percent supported screen time management, 44 percent supported light activity, and only 23 percent supported vigorous activity. When lockdowns canceled sports leagues, closed recreation centers, and emptied playgrounds, those parental levers became almost the only ones left. Qualitative interviews cited in the paper described parents improvising walks and bike rides with their children when structured options vanished, making the family unit the primary behavioral environment for months on end.

Intriguingly, the parent-child link was not uniform across ages and genders. In October 2020, parental guideline compliance predicted higher incidence of guideline compliance among children aged 5 to 11 and among girls, but the associations were weaker or absent for adolescents and, in some analyses, boys. By April 2021, parental compliance predicted compliance among children and among adolescents for the physical activity and sleep guidelines, though not for screen time or the combined guidelines. After adjusting for age and gender, being younger consistently predicted better compliance with the activity, screen time, and combined guidelines at both timepoints, reflecting the well-documented decline in healthy movement as children enter adolescence. The researchers attribute this age gradient to teenagers’ growing independence and orientation toward peers, and to parents’ diminishing sense of control over adolescent screen time and activity choices.

The gender findings add another layer of complexity. In the adjusted April 2021 models, being a girl was associated with a lower incidence of meeting the physical activity and combined guidelines, yet in unadjusted analyses girls were more likely than boys to meet guidelines when their parents did. The authors note that their parent sample was predominantly women, and prior research suggests particularly strong behavioral connections between mothers and daughters, potentially reflecting closer emotional ties and more shared activity. Because so few fathers participated, the study could not disentangle whether mother-child and father-child associations differ, a limitation the team acknowledges alongside the self-reported nature of the data and the inability to compare behavior volumes directly between parents and children.

What emerges from this research is both a warning and an opportunity. Compliance with the 24-hour movement guidelines remained strikingly low for every age group throughout the pandemic’s first year, echoing pre-pandemic Canadian Health Measures Survey figures of 13.9 percent compliance in children, 4.8 percent in adolescents, and 19.1 percent in adults. But the tight coupling of parent and child behavior during lockdowns demonstrates that health promotion efforts aimed at families as units, rather than at children in isolation, could pay dividends precisely when external supports collapse. The authors argue that future public health emergencies should treat the household as the target: encouraging parents to model activity, manage screens, and protect sleep alongside their children. In a crisis that confined families together, the study found, parents did not just share their homes with their children. They shared their habits, for better and for worse.

Subject of Research: Parent-child associations in 24-hour movement behaviours during the COVID-19 pandemic in Canada

Article Title: Associations between parent and child 24-hour movement behaviours across the COVID-19 pandemic in Canada

Article References: Caldwell, H. A., Campbell, J. E., Preston, A., Bhamra, S., Kirk, S. F., Faulkner, G., Tremblay, M. S., & Moore, S. A. (2025). Associations between parent and child 24-hour movement behaviours across the COVID-19 pandemic in Canada. Journal of Activity, Sedentary and Sleep Behaviors, 4(1), Article 10. https://doi.org/10.1186/s44167-025-00081-z

Image Credits: AI Generated

DOI: 10.1186/s44167-025-00081-z

Keywords: physical activity, sedentary behaviour, screen time, sleep, COVID-19, parenting, children, adolescents, 24-hour movement guidelines, public health, Canada, family health

The research, led by Jelle Arts of Amsterdam UMC and colleagues, forms part of the My Little Moves study, a longitudinal observational cohort conducted across the Netherlands. Rather than treating physical activity, sedentary behavior, and sleep as isolated variables, the team embraced a concept that has been gaining momentum in the field: the twenty-four-hour movement composition. Because a child’s day is finite, every minute spent in one behavior is a minute taken from another. Analyzing these behaviors separately, the researchers argue, misses the essential trade-off structure of a young child’s day. Their solution was compositional data analysis, a statistical framework that treats the full daily allocation of time as a single, interdependent whole.

Data collection relied on an unusual tool: a smartphone application called the My Little Moves app, designed specifically for this cohort. Parents recorded their child’s daily activities for seven consecutive days using a time-use diary format, selecting from categories such as playing, sleeping, screen use, passive transport, and personal care. Depending on the activity chosen, the app prompted parents for additional details about intensity, posture, and context. Crucially, the app adapted its content to the child’s developmental stage, asking about motor milestones like crawling, sitting without support, and walking. Parents typically spent between ten and thirty minutes per day completing the diary, and preliminary validation against accelerometer data suggested the method yields reliable results when activities are reported for at least two full days.

The study drew on two sub-cohorts, each followed at two timepoints roughly nine months apart. One sub-cohort focused on social-emotional development, providing complete data for 101 children at baseline, whose average age was just under twenty-one months, and 62 children at follow-up. The other focused on gross motor development and growth, with 60 children at baseline and 46 at the second timepoint. Development was assessed with the Dutch version of the Bayley Scales of Infant and Toddler Development, Third Edition, a widely validated instrument. Researchers also measured children’s weight and height directly, using calibrated scales and stadiometers, to compute body mass index z-scores relative to World Health Organization growth standards.

To represent the movement behavior composition statistically, the team calculated isometric log-ratios, transformed coordinates that capture how much time one behavior occupies relative to the others. These coordinates were then entered into linear regression models for the cross-sectional analysis and linear mixed-effects models for the longitudinal analysis, with the child’s age and sex included as covariates. The mixed-model approach, which uses maximum likelihood estimation, allowed the researchers to include children with data from at least one timepoint without resorting to imputation of missing values. Outliers were screened and removed, and sensitivity analyses confirmed that the handling of influential measurements did not drive the main findings.

The headline result concerns gross motor development. The composition of the twenty-four hours was significantly associated with raw gross motor scores both cross-sectionally and longitudinally, with p-values below .001, although the additional variance explained by the movement composition was modest, at roughly four percent. When the researchers examined which behavior mattered most, a clear pattern emerged: more sedentary time, relative to physical activity and sleep, was linked to lower motor scores, while more sleep, relative to the other behaviors, was linked to higher scores. Physical activity itself, relative to the rest of the day, did not show a significant independent association, a finding that distinguishes this study from earlier work in preschoolers where moderate-to-vigorous activity often took center stage.

The most practically striking numbers came from the compositional isotemporal reallocation analysis, a technique that estimates what would happen to developmental scores if fixed slices of time were shifted between behaviors. Reallocating ten minutes from sedentary behavior to physical activity increased predicted raw gross motor scores by 0.22 points, with a 95 percent confidence interval of 0.11 to 0.33. Shifting the same ten minutes from sedentary behavior to sleep produced an even larger gain of 0.27 points. Conversely, sacrificing ten minutes of sleep in favor of sedentary time cost 0.26 points. In a sample where children spent roughly 55 percent of their day asleep, 30 percent in sedentary pursuits, and only about 14 percent in physical activity, these small per-minute effects accumulate meaningfully across a day, a week, and a childhood.

The growth findings were more surprising. The movement composition was associated with BMI z-scores in the cross-sectional analysis, explaining a medium-sized thirteen percent of additional variance, but the direction of the effects ran counter to expectations. Higher relative sleep was associated with higher BMI z-scores, and higher relative sedentary behavior with lower ones. Shifting ten minutes from sleep to sedentary behavior lowered predicted BMI z-scores by 0.04, while the reverse shift raised them by the same amount. The authors caution that these changes are small and may not be clinically relevant, and they note that the sample’s mean BMI z-scores of 0.7 to 1.0 were likely inflated by the light clothing children wore during measurements, for which no standardized correction exists in this age group. The apparent paradox may also reflect the fact that in very young children, greater physical activity can build fat-free mass, complicating any simple reading of BMI.

Perhaps the most sobering result was the null finding. The composition of movement behaviors showed no significant association with social-emotional development, whether measured as raw or norm-referenced scores, in either the cross-sectional or longitudinal analyses. This mirrors earlier compositional studies by Kuzik and colleagues and St. Laurent and colleagues, which also failed to detect links. The researchers suggest that the social context of activities may matter more than the broad behavioral category: being read to by an adult, for instance, is technically sedentary but may nurture emotional development, whereas unmonitored screen time, also sedentary, may do the opposite. Disentangling these qualitative differences is a task for future research.

The study’s limitations are candidly acknowledged. Dropout was considerable, with complete data available for only about half of the social-emotional sub-cohort at baseline, and the majority of participating parents were highly educated, limiting generalizability. The reliance on parent-reported diaries introduces potential recall and social desirability bias, and parents cannot report activities that occur at daycare. The nine-month follow-up interval may have been too short to capture meaningful developmental change, and limited statistical power meant the models could adjust only for age and sex, not for ethnicity, parental education, or income. Still, the consistency of the motor development findings across both cross-sectional and longitudinal analyses lends them weight. The authors conclude that evidence on the optimal distribution of movement behaviors in early childhood remains inconclusive, and that larger longitudinal studies, ideally incorporating objective measurement and longer follow-up, are essential before the WHO’s twenty-four-hour guidelines for the youngest children can rest on firmer empirical ground. For now, the message for parents is a modest but actionable one: in the economy of a toddler’s day, minutes traded away from stillness toward active play and sleep appear to buy measurable gains in motor development.

Subject of Research: Associations between 24-hour movement behaviors and growth, motor, and social-emotional development in children aged 0 to 4 years

Article Title: Cross-sectional and longitudinal associations between 24-hour movement behaviors and growth, motor, and social-emotional development in early childhood

Article References: Arts, J., Altenburg, T. M., Lettink, A., Verhoeff, A. P., Gubbels, J. S., & Chinapaw, M. J. M. (2025). Cross-sectional and longitudinal associations between 24-hour movement behaviors and growth, motor, and social-emotional development in early childhood. Journal of Activity, Sedentary and Sleep Behaviors, 4(1), Article 14. https://doi.org/10.1186/s44167-025-00085-9

Image Credits: AI Generated

DOI: 10.1186/s44167-025-00085-9

Keywords: early childhood, physical activity, sedentary behavior, sleep, motor development, social-emotional development, BMI, compositional data analysis, Bayley Scales, 24-hour movement guidelines, longitudinal study, My Little Moves

The study, led by Gunchmaa Nyam of Deakin University’s Institute for Physical Activity and Nutrition, drew on baseline data from the TransformUs Secondary effectiveness trial, collected between August 2023 and December 2024. Seven secondary schools across Victoria, Australia, were recruited to capture a diverse mix of government, independent and Catholic schools from metropolitan and regional areas. Of 545 students invited, 193 consented to participate, and after strict quality control of accelerometer data and questionnaire responses, the final analytical sample comprised 124 adolescents aged 13 to 17, with a mean age of 14.8 years. Roughly half of the participants were male, and participants wore wrist-mounted ActiGraph GT9X accelerometers for seven consecutive days, 24 hours a day, providing an objective record of how every minute of their day was spent.

The technical rigour of the measurement is central to the study’s credibility. Accelerometer data were processed using the GGIR package in R, which performed automatic calibration, detection of non-wear time, imputation of invalid data and sleep detection. Participants were only included if they provided at least 16 hours of valid wear time on at least three days, and sleep was estimated using an automated algorithm based on wrist movement variability. Movement intensities were classified using validated age-specific thresholds: sedentary time below 35.6 milligravities, light physical activity between 35.6 and 201.4, moderate activity up to 707.0, and vigorous activity above that. On average, participants accumulated 6.0 valid days of wear, with the devices covering 68 percent of each 24-hour period — a level of objective detail that sidesteps the recall errors and social desirability bias that plague self-reported activity questionnaires.

What the devices revealed was a portrait of modern adolescence that few families would find surprising. On average, the teenagers spent 680.9 minutes — nearly 11.3 hours, or 47.3 percent of the day — in sedentary behaviour. Sleep accounted for 473.0 minutes, or about 7.8 hours. Light physical activity filled 250.7 minutes, roughly four hours, while moderate-to-vigorous physical activity, the intensity most public health guidelines emphasise, occupied a mere 35.3 minutes — just 2.5 percent of the day, and well short of the 60 minutes daily recommended by the Australian 24-Hour Movement Guidelines. The authors note that fewer than 5 percent of Australian adolescents meet all three movement guidelines, a statistic that underscores how far typical routines have drifted from what health authorities consider optimal.

To assess wellbeing, the researchers used the EPOCH Measure of Adolescent Wellbeing, a validated 20-item questionnaire capturing five domains of positive psychological functioning: engagement, perseverance, optimism, connectedness and happiness. Unlike traditional mental health measures that focus on symptoms of illness, EPOCH captures flourishing — the hedonic dimensions of wellbeing such as happiness and optimism, and the eudaimonic dimensions such as engagement and perseverance. Students rated each item on a five-point scale from “Almost never” to “Almost always.” The sample reported moderate to high wellbeing overall, with connectedness scoring highest at 4.35, followed by happiness at 3.92, perseverance at 3.62, optimism at 3.61 and engagement at 3.39.

The analytical approach is where the study departs most sharply from previous work. Time-use data are inherently compositional: because there are only 24 hours in a day, an increase in one behaviour necessarily displaces another, and treating each behaviour in isolation — as most earlier studies did — ignores this interdependence. The researchers therefore applied compositional data analysis, or CoDA, transforming the movement behaviour data using isometric log-ratio (ILR) transformations with pivot coordinates before running compositional linear regression models. Each model was rotated so that every behaviour could be examined relative to all the others, and the models were adjusted for age, gender and school-level clustering. The team also performed a compositional time-reallocation analysis, modelling the hypothetical effect of shifting 30 minutes between pairs of behaviours while holding total daily time constant — a realistic, intervention-sized change.

The results were strikingly specific. Greater time spent in light physical activity relative to all other behaviours was significantly associated with higher happiness scores, while greater sedentary time relative to light activity was significantly associated with lower happiness. The reallocation models quantified the trade-off: shifting 30 minutes from sedentary time to light activity was associated with an increase in happiness scores of 0.128 (95 percent confidence interval: 0.034 to 0.222), while the reverse reallocation produced a significant decrease. Perhaps most unexpectedly, neither moderate-to-vigorous physical activity nor sleep showed significant associations with any of the five wellbeing domains, and no movement behaviour was linked to engagement, perseverance, optimism or connectedness.

The absence of an MVPA effect will raise eyebrows, given the extensive literature linking vigorous exercise to adolescent mental health. The authors urge caution in interpretation, however: the small sample size and low variability in MVPA — most participants managed only about half an hour a day — may have limited the statistical power to detect associations. Context may also matter. Evidence from ecological momentary assessment suggests that outdoor or social activity tends to boost positive affect, whereas indoor, solitary or obligatory activity may not, and competitive or compulsive forms of exercise can even induce stress. Accelerometers, for all their objectivity, cannot distinguish whether a burst of vigorous movement came from a joyful game of basketball or a pressured training session — a nuance the authors flag as critical for future research.

The light activity finding, by contrast, fits an emerging picture. Light-intensity movement such as tai chi or yoga has been associated with reductions in anxiety symptoms, and the authors suggest that gentle activity may represent an accessible, attainable and enjoyable form of movement that facilitates relaxation, casual social interaction and emotional regulation. Sedentary time, meanwhile, has been repeatedly linked to psychological distress and lower self-worth, particularly when it is screen-based — although the authors note that sedentary behaviour also encompasses reading and homework, whose effects may differ from passive screen time. A recent compositional meta-analysis found sleep showed the strongest positive relationship with social-emotional outcomes in children and adolescents, making the null sleep finding here another puzzle that only longitudinal work can resolve.

The study has clear limitations: it was cross-sectional, so causality cannot be established; more than 30 percent of the consenting sample was excluded for insufficient accelerometer data, raising the possibility of non-participation bias, although comparisons between included and excluded participants showed no significant differences in wellbeing or demographics; and there is no established threshold for what constitutes a clinically meaningful change in EPOCH scores. Yet the practical message is hard to ignore. If replacing half an hour of sitting with light movement is associated with even a modest happiness gain, then interventions as simple as encouraging movement during class breaks could support adolescent flourishing without demanding heroic feats of exercise. The authors call for longitudinal and intervention studies to confirm the findings — and to capture not just how much adolescents move, but where, why and with whom.

Subject of Research: Associations between 24-hour movement behaviours and domain-specific psychological wellbeing in adolescents

Article Title: Associations between 24-hour movement behaviours and psychological wellbeing in adolescents using compositional data analysis

Article References: Nyam, G., Lander, N., Ayala, A. M. C., Strugnell, C., & Salmon, J. (2025). Associations between 24-hour movement behaviours and psychological wellbeing in adolescents using compositional data analysis. Journal of Activity, Sedentary and Sleep Behaviors, 4(1), Article 21. https://doi.org/10.1186/s44167-025-00094-8

Image Credits: AI Generated

DOI: 10.1186/s44167-025-00094-8

Keywords: adolescent health, physical activity, sedentary behaviour, compositional data analysis, psychological wellbeing, happiness, EPOCH measure, accelerometer, sleep, MVPA, light physical activity, 24-hour movement guidelines

The 24-Hour Movement Guidelines for the Early Years represent an integrated approach to healthy development in early childhood, recognizing that sleep, physical activity, and sedentary behavior are not isolated habits but interlocking components of a single 24-hour cycle. For children aged 3 to 4 years, the guidelines recommend between 10 and 13 hours of good-quality sleep per day, at least 180 minutes of total physical activity spread across the day, of which at least 60 minutes should be moderate-to-vigorous intensity, no more than one hour of screen time, and no more than one hour of restrained sitting, such as being confined in a stroller, high chair, or car seat for extended periods. Meeting the recommendations individually is one matter; achieving all of them simultaneously on a consistent basis is substantially harder, and that is precisely where the new study focused its attention.

Measurement rigor distinguishes this surveillance effort from earlier surveys that relied largely on parental questionnaires. The research team, led by Sabrina Buchanan and Mark S. Tremblay of the Children’s Hospital of Eastern Ontario Research Institute, together with collaborators from institutions including Western University, Dalhousie University, the University of Alberta, the University of British Columbia, the University of Montreal, Acadia University, and the University of Wollongong, fitted each child with a waist-worn ActiGraph wGT3X+ accelerometer for seven consecutive days and nights. These devices captured objective data on movement intensity and sleep duration, while parents reported on their children’s screen time and time spent restrained in seats and strollers. The study formed part of the SUNRISE International Study of Movement Behaviours in the Early Years and was funded by the Canadian Institutes of Health Research.

Within the final analytic sample of 631 children, 29.0 percent met the overall movement guidelines when accelerometer-estimated measures were prioritized. That headline figure conceals a striking asymmetry in how children performed on each individual behavior. On the positive side, physical activity proved to be a genuine strength of this cohort: every child in the sample accumulated the recommended 180 minutes of total daily physical activity, and 92.4 percent achieved the more demanding threshold of at least 60 minutes of moderate-to-vigorous physical activity per day. Sleep was also largely on target, with between 74.6 percent and 92.0 percent of children meeting the sleep recommendation, depending on whether accelerometer estimates or parent reports were used.

The weak link in the 24-hour equation was sedentary behavior. Only 40.7 percent of children met the sedentary behavior recommendations overall, and the two components told divergent stories. Screen time was the more problematic of the pair, with just 57.1 percent of children staying within the one-hour daily limit, while 71.8 percent met the recommendation for restrained sedentary time. In an era when tablets, smartphones, and televisions are woven into daily family life, the finding that more than four in ten preschoolers exceed recommended screen limits will resonate with pediatricians and early childhood educators who have warned that early excessive screen exposure can displace active play, conversation, and sleep, all of which are critical to brain development during these years.

Beyond the headline prevalence figures, the study uncovered meaningful demographic patterns in who was meeting which guidelines. Girls were significantly less likely than boys to meet the moderate-to-vigorous physical activity recommendation, with an adjusted odds ratio of 0.37, meaning their odds were less than half those of boys. This gender gap, emerging as early as ages 3 and 4, suggests that differences in physical activity participation between males and females are established well before formal schooling begins, reinforcing calls from the study’s authors for targeted strategies to support young girls’ physical activity participation, including inclusive play environments and deliberate encouragement from parents and early childhood educators.

Geography also mattered, though in an unexpected direction. Children living in urban areas were more likely to meet sedentary behavior recommendations than their rural counterparts, with an adjusted odds ratio of 1.51. The authors note that systematic monitoring of preschool movement behaviors has often overlooked subgroups such as males versus females and urban versus rural residents, making these comparisons an important contribution. The rural disadvantage in sedentary time may reflect longer durations spent restrained in car seats during travel to childcare, services, and activities, though the study’s cross-sectional design cannot definitively establish the underlying causes.

Perhaps most intriguing were the age-related findings. Older children within the sample were less likely to meet the overall guidelines, with an adjusted odds ratio of 0.49 per unit increase in age, and less likely to meet sleep recommendations, with an odds ratio of 0.96. Yet the same older children were more likely to meet the moderate-to-vigorous physical activity recommendation, with an odds ratio of 1.08. This pattern suggests that as children approach kindergarten age, their waking hours become more active, but their sleep appears to erode, possibly reflecting later bedtimes, earlier morning routines, or the creeping influence of evening screen use. The net effect is that the delicate balance of the full 24-hour day tips away from the healthy profile as children grow older within the preschool window.

The authors are careful to frame these results within the limitations of a cross-sectional design, which captures a snapshot rather than trajectories over time, and within a sample drawn from childcare settings across five provinces. Methodological choices also mattered: the proportion meeting overall guidelines shifted depending on whether accelerometer-derived sleep estimates or parental reports were prioritized, a reminder that measurement modality can materially alter surveillance conclusions. Even so, the direction of the evidence is consistent with broader international literature showing that very young children are moving enough and sleeping reasonably well but sitting too much in front of screens.

The study’s conclusions point toward a clear public health priority. Because most children in the sample already met sleep and physical activity recommendations, the greatest gains lie in limiting sedentary time, particularly screen time, across the entire preschool population. At the same time, the authors emphasize that continued encouragement of healthy sleep and physical activity remains essential, and that specific, tailored strategies should be developed to support young girls’ physical activity participation. As part of the SUNRISE international surveillance network, this Canadian dataset also provides a benchmark against which future policy interventions, such as screen time guidance, active play programming in early childhood education and care settings, and provincial health promotion campaigns, can be evaluated. With early childhood representing a uniquely plastic developmental window, the difference between 29 percent and a far higher proportion of children meeting all four movement targets may ultimately be measured not in odds ratios but in lifelong health trajectories.

The SUNRISE initiative, of which this Canadian dataset forms a part, was designed to fill a conspicuous gap in global surveillance. While movement behavior monitoring has become routine for school-aged children and adolescents in many countries, comparable data for the early years have been sparse, and the SUNRISE network has sought to harmonize protocols so that preschool findings can eventually be compared across nations with very different childcare systems, climates, and cultural norms around sleep and screen use. The Canadian contribution, spanning five provinces and drawing participants through childcare centres, therefore serves both a national policy purpose and an international comparative one.

The integrated nature of the guidelines themselves reflects a relatively recent shift in thinking among exercise science and pediatric sleep researchers. Earlier guidance treated physical activity, sedentary behavior, and sleep as separate domains with separate targets, but time is inherently finite within a day, so gains in one behavior necessarily displace another. Modeling the full 24 hours as a single continuum allows researchers and practitioners to see trade-offs explicitly, and it explains why the proportion meeting all recommendations simultaneously is so much lower than the proportion meeting any single recommendation in this sample.

The accelerometer protocol also merits attention. Seven consecutive days of waist-worn monitoring captures both weekday and weekend behavior, which matters because preschoolers’ routines often differ markedly between childcare days and home days. Prioritizing device-based estimates over parental report reduces the social desirability bias that plagues questionnaire measures of screen time and sleep, though the divergence between accelerometer-estimated and parent-reported sleep prevalence in this study illustrates that even objective devices rest on assumptions about what constitutes sleep onset and wake.

Finally, the childcare setting through which families were recruited is itself a promising intervention lever. Early childhood education and care environments shape much of preschoolers’ daily movement, and provincial licensing standards governing active outdoor play and screen exposure could translate these surveillance findings into practical policy change.

Subject of Research: Compliance of 3- and 4-year-old Canadian children with 24-hour movement guidelines for sleep, physical activity, and sedentary behavior

Article Title: Proportion of 3- and 4-year-old children meeting individual and combinations of 24-hour movement guidelines across five Canadian provinces: a SUNRISE study

Article References: Buchanan, S., Bremer, E., Bruijns, B. A., Caldwell, H. A. T., Carson, V., Chong, K. H., Faulkner, G., Harandian, K., Hawthorne, M., Kuzik, N., Martins, R., Ong, M., Pagani, L., Potter, M., Tucker, P., & Tremblay, M. S. (2026). Proportion of 3- and 4-year-old children meeting individual and combinations of 24-hour movement guidelines across five Canadian provinces: a SUNRISE study. Journal of Activity, Sedentary and Sleep Behaviors. https://doi.org/10.1186/s44167-026-00113-2

Image Credits: AI Generated

DOI: 10.1186/s44167-026-00113-2

Keywords: 24-hour movement guidelines, preschool children, physical activity, sedentary behavior, screen time, sleep, SUNRISE study, accelerometry, public health surveillance, Canada, early childhood, health promotion

The review, led by Leigh M. Vanderloo of the University of Western Ontario and ParticipACTION, together with Alexandra A. Puchiele, Brianne A. Bruijns, Sarah Carsley, and Patricia Tucker, updates an earlier legislative scan conducted in 2018, before Canada released its first integrated 24-Hour Movement Guidelines for the Early Years. Those guidelines, introduced in 2017 and implemented from 2018 onward, recommend that children aged 0 to 4 accumulate at least 180 minutes of physical activity per day, including energetic play; limit recreational screen time to no more than one hour per day for children aged 2 to 4, and none at all for children under 2; and obtain sufficient nightly sleep ranging from 14 to 17 hours for newborns down to 10 to 13 hours for 3- and 4-year-olds. The World Health Organization followed with its own early years guidelines in 2019 and, in 2021, published global standards for healthy eating, physical activity, sedentary behaviour, and sleep specifically for early childhood education and care settings. The question the research team posed was simple: had Canadian child care legislation caught up?

The methodological approach was straightforward but laborious. In June 2023, the researchers collected the child care acts and regulations for all 13 provinces and territories—Nunavut adheres to the Northwest Territories’ legislature—directly from government websites, cross-checking their selections against the Childcare Resource and Research Unit’s online repository. They then screened every document for keywords covering physical activity and its proxies (gross motor play, energetic play, active play), sedentary behaviour and screen time, sleep and rest, outdoor time, indoor and outdoor space requirements, the 24-Hour Movement Guidelines, and disability or inclusion. Because outdoor play and active play are frequently used in the literature as proxies for physical activity—and because studies show preschoolers accumulate substantially more moderate-to-vigorous activity outdoors than indoors—the team treated these domains as critical indicators of legislative support for movement. Data were extracted into a structured table, verified by a second researcher, and compared across jurisdictions for frequencies, commonalities, and gaps.

The results paint a picture of legislative inconsistency. On the positive side, every province and territory requires daily outdoor play during favourable weather, and all but Saskatchewan embed some form of physical activity requirement tied to developmental milestones. But the specificity ends there. Of the 92 percent of jurisdictions that reference movement-promoting activities, 83 percent provide no requirement for duration, intensity, or method. Only four provinces explicitly use the term physical activity—British Columbia, the Northwest Territories, Nunavut, and Nova Scotia—and only two jurisdictions specify a daily dose: the Northwest Territories requires 30 minutes of physical activity per day, while British Columbia’s Director of Licensing Standard of Practice mandates 120 minutes daily, a target that, if met, would help children achieve two-thirds of the national guideline requirement during child care hours alone.

Screen time fares worse. Only three jurisdictions—British Columbia, New Brunswick, and Quebec—address sedentary behaviour or screen use in their regulations, and only British Columbia and New Brunswick explicitly prohibit screen time in defined circumstances. British Columbia’s rules are the most granular: a maximum of 30 minutes of screen time per day, restrictions on prolonged sedentary behaviour, a prohibition on screen activities in daily programs shorter than three hours or for children younger than two, a requirement that educators model healthy screen behaviour, and a mandate that each centre develop a formal Screen Use Policy. Sleep, by contrast, appears in the legislation of 62 percent of jurisdictions, with New Brunswick and Ontario specifying a maximum of two hours of rest for children and infants, several jurisdictions requiring uninterrupted rest periods, and most requiring consultation with parents about individual sleep patterns.

Perhaps the most consequential finding concerns the integration of the national guidelines themselves. Only one jurisdiction—British Columbia, through its supplementary Active Play Standard—explicitly references the 24-Hour Movement Guidelines in its child care framework, amounting to just 8 percent of provinces and territories. New Brunswick and Quebec independently mention physical activity, sedentary behaviour, and sleep without invoking the integrated framework. This matters because a recent survey found that only 44 percent of Canadian child care centres have a physical activity policy at the centre level, and just 29 percent address screen viewing—and most of those centres cited provincial regulations as the source of their policy. In the absence of clear provincial direction, individual centres are left to invent their own daily metrics, producing wide variability in the movement opportunities afforded to children depending simply on where they live.

The disability analysis is arguably the review’s most sobering contribution. Approximately 13.5 percent of Canadian children under 14 experience difficulty with activities of daily living, and about 62 percent of children aged 0 to 5 with disabilities—roughly 176,000 children—attend child care. Yet only six jurisdictions (Alberta, British Columbia, Newfoundland and Labrador, the Northwest Territories, Nunavut, and Ontario) mention children with disabilities in their regulations at all, and just three—the Northwest Territories, Nunavut, and Ontario—specifically require that activities and play spaces be adapted to support the movement behaviours of children with disabilities. No jurisdiction provided guidance on the meaningful inclusion of children with disabilities in physical activity. The gap is compounded by the fact that the national 24-Hour Movement Guidelines were themselves developed using evidence from children without disabilities, leaving educators without an evidence base tailored to this population. Research cited in the review indicates that children with disabilities are consistently less active than their peers, that achieving adequate movement behaviours is associated with higher school achievement and better self-regulation and emotional health, and that only one in five Canadian child care centres offers high-quality care for children with disabilities. Nearly 10 percent of families report their child was denied a child care space because of a condition.

Why has legislation lagged? The authors point to a persistent misconception that young children are naturally active and therefore need no policy attention—despite mounting evidence that children in child care are highly sedentary. They also note a genuine evidence gap: the Canadian guidelines were built on data from children without disabilities, and the effects of physical activity vary across disability types, meaning some children face barriers to certain activities while others thrive with adapted sports and play. Policymakers, the authors argue, must weigh both outcomes when drafting legislation. The economic stakes are considerable; the federal government has committed $30 billion to a Canada-wide early learning and child care system whose framework explicitly prioritizes the participation of children with disabilities.

The evidence that policy works is compelling. A meta-analysis by Saravanamuttoo and colleagues found that children attending centres with formalized physical activity policies engaged in significantly more activity than children in centres without them. In Australia, a pragmatic cluster randomized trial across 81 centres found that requiring policy implementation over three months significantly increased director-reported policy practices. Studies in New Zealand and the United States report similar patterns, while Australia’s state-based National Quality Framework demonstrates that federated systems can still standardize care—a relevant comparison for Canada’s 13 distinct legislative regimes. Experimental work also underscores the value of outdoor time: one study calculated that a preschooler needs only 3.8 minutes outdoors to accumulate one minute of moderate-to-vigorous physical activity, compared with 9.1 minutes indoors.

The authors acknowledge limitations. The existence of legislation does not guarantee implementation, enforcement, or quality, and educator training remains essential; Alberta’s 2017 accreditation standard, which lacks specific time requirements, produced no measurable change in children’s in-care activity in a subsequent evaluation. Generalizability beyond Canada is also limited. But the core message is unambiguous: at a moment of unprecedented federal investment and public attention, provinces and territories have a rare opportunity to legislate clear, evidence-based movement behaviour targets—and to pair them with training, resources, and inclusive programming—so that every child in care, with or without a disability, gets an equal start on a healthy trajectory.

The research team—co-first authors Zhiyong Yang and Jingjing Shao together with senior author Ying Shen, all affiliated with Nanjing Medical University and its hospitals in China—mined the National Survey of Children’s Health (NSCH), an annual, nationally representative survey administered by the U.S. Census Bureau under the direction of the Health Resources and Services Administration’s Maternal and Child Health Bureau. In each wave, a parent or caregiver completes an extensive questionnaire about one randomly selected child in the household, and the responses carry sampling weights that allow estimates to be projected onto the full U.S. child population. The investigators pooled the public-use topical files from 2018 through 2024, capturing 209,556 age-eligible children aged 6 to 17. Because the survey asks follow-up diagnostic questions only of families who flag relevant concerns, the team applied explicit rules for handling questionnaire-design skips and for children whose current diagnostic status could not be determined; 206,636 children carried a classifiable ADHD and learning-disability status. The fully adjusted models ultimately drew on 196,143 children for the school-functioning outcome and 197,776 for the school-contact outcome.

The exposure at the heart of the study is the 24-hour movement-behavior framework, an integrated way of thinking about a child’s entire day rather than a set of isolated habits. The framework divides the day into three interacting behaviors—physical activity, recreational screen time and sleep—and treats them as a package, on the logic that time spent in one behavior necessarily displaces time in another: an extra hour of evening screen time is an hour not spent asleep, and a sedentary afternoon is an afternoon without the energy expenditure that activity guidelines prescribe. The integrated guidelines typically call for at least 60 minutes of moderate-to-vigorous physical activity each day, recreational screen time held to roughly two hours or less, and nightly sleep in age-appropriate amounts. For each child, the researchers counted how many of the three guidelines were met, producing a score from 0 to 3. The simple count conceals eight possible behavior combinations, and the team separately probed whether particular patterns—such as pairing high activity with long sleep—carried distinct signatures, alongside component-specific models that tested each behavior on its own.

The study’s central methodological move is a cross-classification. Rather than lumping children with any neurodevelopmental diagnosis into a single contrast group, the team sorted children into four mutually exclusive categories: those with neither current ADHD nor a current learning disability, those with ADHD alone, those with a learning disability alone, and those with both conditions. The rationale is statistical as much as clinical. Children with co-occurring ADHD and learning disability start from a markedly lower baseline of school functioning, and merging them with other groups can mask or distort the relationship between movement behaviors and outcomes. By stratifying on diagnosis and then examining the guideline gradient within each stratum, the researchers could disentangle two distinct questions: whether meeting more movement guidelines is associated with better school functioning, and whether that association differs for children whose classroom difficulties arise from neurodevelopmental conditions.

Two caregiver-reported outcomes anchored the analysis. The first, higher school functioning, reflects parents’ assessments of how well their child is doing at school. The second captures whether the child’s school had initiated contact with the family about school problems—a signal, arguably closer to institutional reality, that classroom difficulties had risen to the level of formal attention. The team fitted survey-weighted logistic regression models, the standard tool for complex national samples in which each child carries a sampling weight and children drawn from the same household or primary sampling unit are statistically dependent, with covariate adjustment for demographic, socioeconomic, family-structure and survey-year factors. Compared with children meeting zero guidelines, those meeting all three had 3.87 times higher odds of higher school functioning (95% confidence interval, 3.50–4.28) and roughly half the odds of school-initiated contact about problems (odds ratio, 0.49; 95% confidence interval, 0.44–0.54). In survey-weighted analyses of this scale, narrow confidence intervals are typical, but the consistency of effect direction across models is the more telling signal.

An odds ratio of nearly four, estimated from a sample approaching a quarter of a million children, is striking in isolation; its consistency is what elevates the finding. The favorable, graded pattern for higher school functioning—each guideline met associated with a further step up in the odds—appeared across all four ADHD and learning-disability strata. Children with neither condition, those with ADHD only, those with a learning disability only, and those with both all showed the same directional climb, meaning the movement-behavior gradient operates in parallel with, not instead of, diagnosis. But the stratified lens also revealed what the gradient could not do: it did not lift children with co-occurring ADHD and learning disability out of their position on the lowest functional baseline. The authors present this as the clearest payoff of the cross-classification design—two phenomena, an overall gradient tied to healthy daily behaviors and persistent diagnostic differences in baseline burden, can be seen and quantified side by side, information that single-group analyses would have folded together and lost.

One subgroup result breaks the tidy pattern, and the researchers flag it with visible caution. In the ADHD-only group, the association between guideline attainment and school-initiated contact was non-monotonic: at the full three-guideline level, the expected decline in school contact did not follow the smooth, stepwise trajectory observed elsewhere. The team explicitly treats this as an exploratory signal requiring replication rather than a reliable subgroup effect. In observational epidemiology, non-monotonicity confined to a single stratum of a cross-sectional survey is exactly the kind of pattern that can arise from chance, sparse cell counts or residual confounding, and resisting the temptation to headline it reflects a deliberately conservative analytic posture. Notably, the authors state that the wider suite of component-specific, pattern-based, original-category and sequential-adjustment analyses did not materially alter the primary interpretation, meaning the headline association survived even as the odd subgroup signal was quarantined.

That conservatism is visible throughout the paper, which follows the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist for cross-sectional research and subjects the primary models to an unusually broad battery of sensitivity tests. Threshold sensitivity analyses asked whether the results depended on where cutoffs were drawn for each behavior. Age-split and period-split models—dividing children into younger and older bands, and the survey years into earlier and later windows—tested developmental and temporal stability across the 2018–2024 span. Pattern-based analyses examined whether particular combinations of the three behaviors outperformed the simple count of guidelines met, and sequential-adjustment models added covariate blocks stepwise to trace how the estimates moved as confounders accumulated. Component-specific models isolated each behavior in turn, and an original-category coding preserved the survey’s native response options rather than collapsing them. None of these alternatives overturned the central conclusion, lending the association a robustness that many single-model cross-sectional studies lack.

The design still imposes limits the authors are careful to acknowledge. As a pooled cross-sectional analysis, the study captures snapshots rather than trajectories; it can document association but cannot establish that adopting healthier movement habits improves school functioning, and reverse causation remains plausible—children who struggle academically may sleep less, move less and retreat further into screens. Every exposure and outcome rests on caregiver report, which can be shaped by parental perception, recall and, in some cases, by the very school difficulties under study; the survey’s skip design, though explicitly handled, means diagnostic status derives from parental report rather than clinical assessment. Even models rich in demographic, socioeconomic and family-structure covariates cannot exclude residual confounding by unmeasured factors such as symptom severity, parenting practices or neighborhood resources. Because the data are de-identified and publicly available, the analysis was exempt from institutional review board review under U.S. federal regulations governing research with human subjects data.

For clinicians, educators and families, the practical message is nonetheless concrete. Sleep, physical activity and recreational screen time are among the few modifiable, everyday behaviors within reach of most households, and the graded association observed here—if confirmed by longitudinal and intervention studies—would position the 24-hour framework as a low-cost complement to individualized educational and behavioral supports rather than a replacement for them. The work, supported by the Maternal and Child Health Research Project of Jiangsu Province, the Research Fund for the Career Development of Young and Mid-career Physicians in Child Development and Behavior of the China International Medical Foundation, and the Science and Technology Development Fund of Nanjing Medical University, was published open access on 29 August 2026. The authors’ own summary is deliberately measured: greater 24-hour movement-behavior guideline attainment was associated with more favorable school-related functioning among U.S. school-aged children, and the ADHD-by-learning-disability cross-classification added clinically relevant information by separating the movement gradient from persistent diagnostic differences in baseline burden. For the millions of children navigating both classrooms and neurodevelopmental diagnoses, the whole day—how they move, sleep and unplug—may matter as much as any single intervention.