The study, led by Johanna Hänggi of the Swiss Tropical and Public Health Institute and the University of Basel, set out to answer a deceptively simple question: does the way parents divide their waking hours between sitting, moving lightly, and exercising vigorously predict how their children divide the same hours? Previous evidence on this point has been inconclusive. Systematic reviews of children aged six to twelve support the idea that parents model activity for their offspring, particularly in father-son and mother-daughter pairs, but reviews restricted to device-based measurements found only weak positive correlations between parent and child activity. Longitudinal studies, which can reveal whether parental behavior actually shapes children’s behavior over time rather than merely coinciding with it, have been rare, and those that exist often relied on self-reported activity, which is vulnerable to recall errors and the human tendency to overstate virtuous behavior.

The SOPHYA team addressed these gaps with an unusually rigorous design. All children aged six to sixteen born and registered in Switzerland between 1998 and 2007 were eligible, and a random sample was drawn from the national population registry, stratified by birth year to ensure balanced age groups. Baseline assessments took place in 2013 to 2015 and follow-up assessments in 2019 to 2020. Rather than asking families to estimate their own activity, the researchers mailed pre-programmed ActiGraph accelerometers to participants, who wore the devices on the right hip for seven consecutive days while keeping diaries of non-wear periods. To be included, participants needed at least three weekdays of ten hours or more of wear time and at least one weekend day of eight hours, with weekday and weekend data weighted five to two to reflect a full week.

The baseline sample ultimately included 686 mother-child pairs and 373 father-child pairs with valid accelerometer and questionnaire data from the same measurement week, and 337 of those children provided valid follow-up data, yielding 263 mother-child and 149 father-child pairs for the longitudinal analysis. Sedentary behavior was defined as fewer than 100 counts per minute, while moderate-to-vigorous activity thresholds were age-adjusted for children and set at a level corresponding to four metabolic equivalents. Light activity occupied the range in between. From these raw counts the researchers computed each person’s waking movement composition: the proportions of wear time spent sedentary, in light activity, and in moderate-to-vigorous activity.

Analyzing those proportions required a statistical approach suited to compositional data. Because the three behavior categories must sum to the whole of wear time, an increase in one necessarily means a decrease in another, and standard regression techniques that treat each category separately can produce misleading results. The team instead applied Dirichlet regression, a method that preserves the compositional structure of the outcome and directly handles the skewness and heteroscedasticity typical of such data. Parental movement compositions were transformed into additive log-ratios, with sedentary behavior as the reference component, producing two intuitive predictors: the log-ratio of moderate-to-vigorous activity to sitting, and the log-ratio of light activity to sitting. Models were adjusted for the child’s age and sex, parental education, and language region, and the researchers tested whether the associations varied by the child’s age or sex.

The cross-sectional results were consistent across both parents. When mothers replaced sedentary time with moderate-to-vigorous activity, the ratio of that activity to sitting in their children rose in parallel, with a coefficient of 0.10 and a p-value below 0.001; the equivalent paternal coefficient was 0.09 with a p-value of 0.002. Replacing sitting with light activity produced even clearer associations: 0.13 for mothers and 0.09 for fathers, both statistically significant. In plain terms, when mothers or fathers traded sitting for movement of either intensity, their children tended to do the same. Notably, these associations did not depend on the child’s age or sex, suggesting that the link between parental and child movement patterns operates broadly across the six-to-sixteen age range and across both sexes.

The longitudinal findings, though based on a smaller sample, carried the analysis into territory few studies have reached. Five years after the baseline measurement, mothers’ replacement of sitting with light activity still predicted a similar shift in their children, with a coefficient of 0.12 and a p-value of 0.021. The paternal equivalent was directionally similar at 0.10 but fell short of conventional statistical significance at p equal to 0.108, likely reflecting the smaller number of father-child pairs. One intriguing exception emerged: a mother’s shift from sitting to moderate-to-vigorous activity was associated with a larger light-activity response in daughters than in sons, hinting at same-sex modeling dynamics that echo the team’s earlier SOPHYA findings of stronger mother-daughter and father-son activity associations independent of socioeconomic and neighborhood factors.

The effect sizes deserve careful interpretation. When the researchers modeled a parent cutting sedentary time by twenty percent and increasing light activity by the same amount, the predicted change in the child’s light-activity-to-sitting ratio was about eighteen times smaller than the mother’s actual observed shift and about twenty-nine times smaller than the father’s. Children, in other words, move part of the way with their parents but do not mirror them completely. Ternary plots, which display the three movement components as axes of a triangle, illustrated this graphically: parental trajectories from the most sedentary to the least sedentary compositions produced child trajectories in the same direction but of visibly smaller magnitude. The study also found that children’s sedentary share of wear time climbed from about sixty percent at baseline to seventy-three percent at follow-up, underscoring how strongly the adolescent years pull toward sitting.

For public health, the implications point toward family-level intervention design. Because mothers at the low end of sedentary time compensated almost entirely with light activity, while fathers at the low end increased both light and moderate-to-vigorous activity, the authors argue that interventions should not fixate exclusively on vigorous exercise. Light-intensity movement carries documented health benefits for adults and children alike, and the strong, consistent associations within both intensity domains suggest that simply getting parents off the couch and into gentle motion may pay dividends across the whole household. Meta-analytic evidence shows that dyadic interventions targeting shared goals can reduce sedentary behavior, yet programs that address compositional movement patterns remain scarce.

The authors are candid about limitations. The cross-sectional analysis cannot rule out reverse causation, in which active children encourage active parents, and the smaller longitudinal sample limited statistical power, particularly for detecting sex-specific effects among fathers. Sleep was not objectively measured, so the analysis captures only waking behavior rather than the full twenty-four-hour profile, and the findings may not generalize beyond Switzerland’s cultural and socioeconomic context. Attrition bias appears unlikely to distort the results, however, because follow-up participation was not associated with baseline movement composition of either parents or children. The overall message stands: parental movement patterns, and sedentary time in particular, may be effective targets for interventions that benefit parents and children simultaneously, with effects that persist over years rather than fading with the measurement week. As the researchers conclude, integrating family-based strategies into physical activity promotion could yield long-lasting benefits, even if each individual shift is modest.

Subject of Research: Cross-sectional and longitudinal associations between parental and youth movement compositions measured by accelerometry in the Swiss SOPHYA cohort

Article Title: Movement patterns of youth and their parents: cross-sectional and longitudinal associations

Article References: Hänggi, J., Lovison, G., Jeong, A., Dössegger, A., Taube, W., Kayser, B., Suggs, S. L., Bringolf-Isler, B., & Probst-Hensch, N. (2026). Movement patterns of youth and their parents: cross-sectional and longitudinal associations. Journal of Activity, Sedentary and Sleep Behaviors, 5(1), Article 2. https://doi.org/10.1186/s44167-025-00092-w

Image Credits: AI Generated

DOI: 10.1186/s44167-025-00092-w

Keywords: physical activity, sedentary behavior, parent-child dyads, accelerometry, compositional data analysis, SOPHYA cohort, longitudinal study, light physical activity, moderate-to-vigorous activity, youth health, behavioral modeling, Switzerland