Correlates of physical activity in 0- to 5-year-olds: a systematic umbrella review and consultation of international researchers

Many children aged 0–5 years do not meet the WHO physical activity guidelines. To develop effective, evidence-based interventions, it is necessary to understand which factors are associated with physical activity in early childhood.

The objective of this studie is to summarize the current evidence on correlates of physical activity in 0- to 5-year-old children.

Methods
First, a systematic umbrella review was conducted following PRISMA guidelines. PubMed, Embase, PsycINFO, and SPORTDiscus were searched up to May 2020 for systematic reviews examining the association between potential correlates and quantitatively measured physical activity in children aged 0–5.9 years. Included reviews were assessed on methodological quality, and results were categorized according to the socio-ecological model.

Second, 31 international researchers of physical activity in young children participated in an expert panel to reflect on the outcomes of the umbrella review and propose directions for future research.

Results
Twenty-one reviews were included that examined a total of 98 potential correlates. When synthesizing all reviews, 23 correlates were found with consistent evidence for an association with a physical activity outcome. For most other potential correlates there was inconsistent evidence across reviews for associations with physical activity in young children.

Although there was little overlap between the correlates identified in the umbrella review and determinants suggested by the expert panel, both confirmed the importance of socio-cultural, policy, and physical environmental factors in general.

Conclusion
Multiple correlates of young children’s physical activity were identified. However, various methodological challenges (e.g., measurement instruments) and the large heterogeneity (e.g., study samples, correlates, and outcome measures) hindered formulating definitive conclusions. Moreover, none of the reviews reported on the interrelatedness between correlates, which would align with more holistic understandings of behavior.

Our findings indicate the urgent need for establishing a common ground in definitions, assessment methods, and analytical methods to further the field of physical activity research in this tremendously important age group.