Evaluation of a Pilot School-Based Physical Activity Clustered Randomised Controlled Trial—Active Schools: Skelmersdale

Medicine &Amp; Science in Sports &Amp; Exercise

Yates

et al. 2019

The physical activity profile can be described from accelerometer data using two population-independent metrics: average acceleration (ACC, volume) and intensity gradient (IG, intensity). This paper aims to: 1) demonstrate how these metrics can be used to investigate the relative contributions of volume and intensity of physical activity for a range of health markers across datasets; and 2) illustrate the future potential of the metrics for generation of age and sexspecific percentile norms. Methods: Secondary data analyses were carried out on five diverse datasets using wrist-worn accelerometers (ActiGraph/GENEActiv/Axivity): children (N=145), adolescent girls (N=1669), office workers (N=114), pre-(N=1218) and post-(N=1316) menopausal women, and adults with type 2 diabetes (T2D) (N=475). Open-source software (GGIR) was used to generate ACC and IG. Health markers were: a) zBMI (children); b) %fat (adolescent girls and adults); c) bone health (pre-and post-menopausal women); and d) physical function (adults with T2D). Results: Multiple regression analyses showed the IG, but not ACC, was independently associated with zBMI/%fat in children and adolescents. In adults, associations were stronger and the effects of ACC and IG were additive. For bone health and physical function, interactions showed associations were strongest if IG was high, largely irrespective of ACC. Exemplar illustrative percentile 'norms' showed the expected age-related decline in physical activity, with greater drops in IG across age than ACC. Conclusion: The ACC and IG accelerometer metrics facilitate investigation of whether volume and intensity of physical activity have independent, additive or interactive effects on health markers. Future, adoption of data-driven metrics would facilitate the generation of age-and sexspecific norms that would be beneficial to researchers.

Section: Samplesmentioning

confidence: 99%

Activity Intensity, Volume, and Norms: Utility and Interpretation of Accelerometer Metrics

Medicine &Amp; Science in Sports &Amp; Exercise

Yates

et al. 2019

“…Phase 1 was a cross-sectional observation study, 18 Phase 2 tested the feasibility of PA intervention components, 20 and Phase 3 was a pilot multicomponent PA intervention. 17 Data from Phases 1 and 3 (baseline only) were included in the present study. Data collection took place between October and December 2016 (Phase 1) and between September and October 2017 (Phase 3).…”

Section: Participantsmentioning

confidence: 99%

Cut‐point‐free accelerometer metrics to assess children’s physical activity: An example using the school day

Scandinavian Med Sci Sports

Taylor

et al. 2019

Self Cite

Funding informationEdge Hill University; West Lancashire Sport PartnershipThe aims were to (a) investigate associations between a novel accelerometer metric: the minimum acceleration value above which the most active 30-minutes were accumulated during the school day (M30 ACC ), and health indicators, and (b) demonstrate that applying an equivalent cut-point to the M30 ACC metric gives comparable prevalence results as a moderate-to-vigorous physical activity (MVPA) cut-point approach. Two hundred and ninety-six children (age 9-10-years) wore wrist-mounted accelerometers for 7-days. School day MVPA and M30 ACC were calculated. Body mass index (BMI), waist-to-height ratio (WHtR), and cardiorespiratory fitness (CRF) were also measured. Mixed linear models investigated associations between M30 ACC and health indicators. Agreement between ranked MVPA and M30 ACC values was assessed using percent agreement, kappa, sensitivity, and specificity statistics. M30 ACC thresholds associated with health indicators were 213 mg (BMI), 206 mg (WHtR), and 269 mg (CRF) for girls. The equivalent values for boys were 234 mg (BMI), 230 mg (WHtR), and 327 mg (CRF). Less than half of girls and 75% of boys accumulated 30 minutes of school day MVPA. Just <50% of girls and >80% of boys had M30 ACC values ≥200 mg, which is equivalent to brisk walking. Agreement between MVPA and M30 ACC tertiles was high, reflected by the sensitivity and specificity values of >90%. Results demonstrate the utility of M30 ACC as a PA metric that is not heavily influenced by researcher decisions. M30 ACC has potential as an accelerometer-specific metric for generating PA guidelines related to health indicators and easily understood forms of activity such as brisk walking. K E Y W O R D Sacceleration, accelerometer, children, cut-points, guidelines, physical activity, school 118 | FAIRCLOUGH et AL.

“…Application of different cutpoints can result in vastly different estimates of PA (5), which is confusing for interpretation and translation of data for surveillance and intervention evaluation. Most of the studies that have used raw accelerations to describe PA outcomes (6)(7)(8)(9) have employed the Euclidean norm minus one g (ENMO) metric to summarise the raw acceleration signal vector magnitude (10). They have also applied acceleration cutpoints from the laboratory calibration study of Hildebrand et al (2014) (2), which involved a convenience sample of 30, 7-11 year old children.…”

Section: Introductionmentioning

confidence: 99%

Average acceleration and intensity gradient of primary school children and associations with indicators of health and well-being

Taylor

Journal of Sports Sciences

et al. 2019

Self Cite