Moderate and vigorous physical activity show intensity specific familial and interpersonal association patterns in 9-12-year-olds: A cross-sectional DE-PASS study.

BACKGROUND: Research on children's physical activity often examines interpersonal associations but commonly aggregates MPA and VPA into a single MVPA outcome. This approach may obscure intensity-specific association patterns, particularly in intergenerational analyses. METHODS: This cross-sectional study used harmonized data from the European DE-PASS project, including children aged 9-12 years and one of their parents. Waist-worn accelerometry was used to assess MPA and VPA. Perceived parental, peer, and teacher support were measured using validated questionnaires. Intensity-specific associations between parent and child physical activity and between interpersonal support variables and children's activity were examined, including sex-stratified and socioeconomic sensitivity analyses. RESULTS: Parent-child associations differed by activity intensity. Parent-child resemblance was numerically larger for MPA than for VPA, although the difference between intensities was not statistically significant when formally compared; associations involving VPA were weaker and less consistent. Parental co-participation support showed a weak positive association (which did not survive correction for multiple testing) with children's MPA, whereas peer and teacher support showed limited or no associations with children's activity at either intensity. Sex-stratified analyses indicated similar MPA associations across boys and girls, while associations for VPA were not observed among girls. Aggregating MPA and VPA into MVPA may obscure these intensity-specific patterns. CONCLUSIONS: These findings indicate that interpersonal associations with children's physical activity differ by intensity and support examining MPA and VPA as intensity-specific outcomes in intergenerational analyses. Family-based approaches focusing on MPA may represent a pausible direction for future longitudinal and intervention research, while different strategies may be needed to address VPA.