A Randomized Controlled Trial of a Blended Physical Literacy Intervention to Support Physical Activity and Health of Primary School Children.

Background: The concept of physical literacy (PL) has been advocated as the need to create environments fostering sustainable engagement in PA. This study adopted ecological approach to evaluate the effectiveness of a blended PL intervention embedded into the school day to support children's PA and health.

Method: Designed as a three-arm randomized controlled trial, a total of 79 participants (59.5% girls) were randomly assigned to: the "Quantity + Quality" blended PL group combining sit-stand desks and play-based recess (SSPlay), the "Quality" group with play-based recess only (Play) or the control group. The intervention lasted for 13 weeks, and all the variables were collected at baseline, post-intervention and 3-month follow-up.

Results: SSPlay and Play group significantly improved on two of the embodied PL domains, Physical Competence (- 2.96 vs - 5.15, p < 0.05) and Knowledge and Understanding (- 2.35 vs - 2.00, p < 0.05), total errors of cognitive flexibility (24.00 vs 12.92, p < 0.05), and this difference was maintained at follow-up (p < 0.05). Whilst there was no interaction effect between groups, and time effects were found for PA and planning from baseline to post-intervention.

Conclusion: This was the first to adopt an ecological approach as an innovative strategy to provide the emergence of PA for children in Hong Kong. The blended intervention design that embedded both quantity and quality of PA into children's school day has shown promise in supporting children's all round development. PL intervention where environments are designed to increase the "Quantity + Quality" of children's everyday interactions has led to improvements in PA and health outcomes, which may provide insights for future studies to adopt cost-friendly and feasible measures for promoting children's PA in the school settings.

Trial registration: ChiCTR, ChiCTR2000035038. Registered 29 July 2020-Retrospectively registered. http://www.chictr.org.cn/hvshowproject.aspx?id=46038 .