A Cluster-Analytic Classification of Children's Physical Activity: The Change! Project

Introduction Physical activity is a major public health concern as trends show inadequate levels of physical activity for health and rising levels of obesity. A research priority is understanding key explanatory variables underpinning children’s physical activity participation. Despite this, there are few studies identifying “clusters” of children based on their physical activity classification levels. This study used cluster analysis in identifying physical activity patterns of children, examining whether different physical activity clusters differ on key explanatory variables.

Methods Two hundred and eighty-nine children (54.7% girls) aged 10-11 years old from 12 primary schools in North-West England completed the Children’s Physical Self-Perception Profile, items of Enjoyment, items of Self-Efficacy, and wore a physical activity monitor (GT1M ActiGraph) for seven consecutive days. Sample-specific cut points were generated using a ROC analysis approach in a sub-study based on the recommendations of Welk (2005). Anthropometric measures were completed to estimate maturity status. Cluster analysis was performed to identify homogeneous groups of children based on similar time spent in sedentary, light physical activity (LPA), moderate physical activity (MPA), moderate-to-vigorous physical activity (MVPA) and vigorous physical activity (VPA). Multivariate analyses of variance were then performed to examine differences between clusters on psychological variables and gender.

Results Cluster analysis yielded a four-cluster solution, reflecting low activity, average activity, moderate activity and vigorous activity groupings. There were significant differences in physical activity classifications between all clusters.

Discussion Children who spend more time in MPA and VPA have higher self-perceptions for sport competence, physical condition, body attractiveness, perceived strength, physical self-worth and global self esteem,but not for enjoyment or self-esteem. Notably, these results also indicate maturity status may differentially influence boys’ and girls’ physical self-perceptions.

References Welk, G.J. (2005). Med Sci Sports Exerc, 37, S501-S511.