The aim of this study is to examine the effects of a kindergarten-based, parent-involved intervention during the upper kindergarten year (K3) on physical activity and physical fitness in preschool children.

This study is a two-arm cluster randomized controlled trial. Kindergartens will be randomly allocated to two groups: the usual care group and the intervention group. The usual care group will continue with their usual curriculum, which includes 30 minutes of daily physical activity stipulated by the Hong Kong SAR Government's Education Bureau. The intervention group will receive an additional 2.5 hours of physical activity per week in addition to the stipulated 30 minutes of daily physical activity. Outcome measures will be examined at baseline, 10 months (post-intervention), and 16 months (follow-up).

Inclusion Criteria

1. Children aged 5-6 years (limited number of children may be between 4-5 and 6-7 years)
2. Able to communicate in Chinese
3. Able to participate in physical activity in a standard kindergarten setting

Exclusion Criteria:

1. Inherent or serious disease limiting participation in physical activity (e.g., congenital heart disease, pediatric cancer, Down syndrome).
2. Diagnosed mental illness impairing daily behavior and performance (e.g., anxiety disorder, depression, attention deficit hyperactivity disorder, psychotic disorders, autism spectrum disorder).
3. Physical disability (e.g., physical handicap, assistive device to walk).
4. Visual or hearing impairment.
5. Cognitive deficit or intellectual disability that requires special care and educational needs (e.g., handicapped children with learning difficulties).

The data of individual participants that underlie the results reported in this trial, after de-identification including text, tables, figures, and appendices, as well as study protocol and statistical analysis plan, will be shared after 3 months of study publication. Data will be shared with researchers who provide a methodologically sound proposal for academic purposes. Proposals should be directed to pmsiu@hku.hk to gain access and for data request, a data-access agreement needs to be signed.

Beginning 3 months and ending 3 years following the publication of the article.

Data will be shared with researchers who provide a methodologically sound proposal for academic purposes. Proposals should be directed to pmsiu@hku.hk to gain access and for data request, a data-access agreement needs to be signed.