The use of the intensity gradient and average acceleration metrics to explore associations with BMI z-score in children

ABSTRACT

This study used the intensity gradient (IG) and average acceleration metrics to describe children’s activity profiles and explore associations with body mass index (BMI) z-score. Two hundred and forty-six children (n = 138 girls) aged 9.6 ± 1.4 years wore a wrist-mounted ActiGraph wGT3X-BT accelerometer for 7 days on their non-dominant wrist. Physical activity (PA) metrics captured included: the IG which describes the intensity distribution of accelerations across the 24 h monitoring period; average acceleration which provides a measure of the volume of activity; total moderate-to-vigorous PA (MVPA) and inactive time. Acceleration was averaged over 5s epochs. Finally, BMI z-score was calculated for each participant. Average acceleration was negatively associated with BMI z-score (p < 0.05) independent of age and gender but not IG. The IG was negatively associated with BMI z-score independent of potential correlates and average acceleration. Total MVPA was not associated with BMI-z score. The IG and average acceleration metrics may be used to explore the independent or cumulative effects of the volume and intensity distribution of activity upon measures of health and well-being in children to inform specific activity recommendations.     

In Pursuit of School Ethos

The purpose of this paper is to examine the linkages and relationships between the officially prescribed school ethos and that which emerges from social interaction. Qualitative data drawn from one Grant-Maintained-Integrated and one Catholic primary school in Northern Ireland show how school ethos, defined as the observed practices and interactions of school members, often departs considerably from school ethos defined as those values and beliefs which the school officially supports. On the basis of the data it is argued that much of what we understand of school ethos is superficial and contradictory. With this in mind the paper concludes by presenting a new angle on ethos which, when taken in conjunction with the other perspectives, further enhances our understanding of how schools work.