Levels and patterns of physical activity and sedentary time among superdiverse adolescents in East London: a cross-sectional study

Objectives: Little is known about the physical activity (PA) and sedentary time (ST) habits of adolescents from superdiverse communities in the UK. The objectives of this study are to examine and report the patterns of PA/ST among adolescents in East London living in superdiverse communities, to identify opportunities/barriers to PA and inform policy/practice. Design: 1,260 young people (aged 11-13) young people from 7 secondary schools in East London completed a questionnaire on PA/ST over the past 7 days as part of the Newham's Every Child a Sports Person (NECaSP) intervention. Socio-demographic and anthropometric data were obtained. Significance tests were conducted to determine differences between socio-demographic and anthropometric predictors and PA/ST. Multinomial logit regression was used to explore the effects of ethnicity, sex and BMI on PA levels. Results: Males were significantly more likely to engage in PA at least 5 times during school in the past week (U=5.07, z= -11.76, p< .05). Obese participants were less likely to report engaging in PA 5 times in the past week (U=4.11, z= -1.17, p< .05). Black Caribbean girls (U=5.08, z= -1.92, p< .05) were significantly more likely to report engaging in no activity. Multinomial logit regression analyses revealed that girls with higher BMI were less likely to engage in PA at least 4 times after school in the last week than boys (b=.11, Wald X2(1)=9.81, p< .01). Walking (36.4%), jogging/running (29.9%), and football (28%) were the most frequently reported activities. Conclusion: Engaging girls in PA during and after school is important and making sports clubs and activities available and attractive to this target group may help increase engagement in PA and reduce ST. Findings support the need for more sex-specific and culturally responsive pedagogy in schools with curricula that respects diversity and individuality and has meaning and value amongst superdiverse young people. Finally, we need to extend current work presented and provide substantial evidence of the ways young people from minority ethnic groups process and act on the public health policy and the ways they understand and enact physical activity

A Sex-Specific Metabolite Identified in a Marine Invertebrate Utilizing Phosphorus-31 Nuclear Magnetic Resonance

Hormone level differences are generally accepted as the primary cause for sexual dimorphism in animal and human development. Levels of low molecular weight metabolites also differ between men and women in circulating amino acids, lipids and carbohydrates and within brain tissue. While investigating the metabolism of blue crab tissues using Phosphorus-31 Nuclear Magnetic Resonance, we discovered that only the male blue crab (Callinectes sapidus) contained a phosphorus compound with a chemical shift well separated from the expected phosphate compounds. Spectra obtained from male gills were readily differentiated from female gill spectra. Analysis from six years of data from male and female crabs documented that the sex-specificity of this metabolite was normal for this species. Microscopic analysis of male and female gills found no differences in their gill anatomy or the presence of parasites or bacteria that might produce this phosphorus compound. Analysis of a rare gynandromorph blue crab (laterally, half male and half female) proved that this sex-specificity was an intrinsic biochemical process and was not caused by any variations in the diet or habitat of male versus female crabs. The existence of a sex-specific metabolite is a previously unrecognized, but potentially significant biochemical phenomenon. An entire enzyme system has been synthesized and activated only in one sex. Unless blue crabs are a unique species, sex-specific metabolites are likely to be present in other animals. Would the presence or absence of a sex-specific metabolite affect an animal's development, anatomy and biochemistry

The effectiveness of school-based physical activity interventions for adolescent girls: a systematic review and meta-analysis

Physical activity (PA) decreases during the transition from childhood to adolescence, with larger declines observed in girls. School-based interventions are considered the most promising approach for increasing adolescents' PA levels although, it is unclear which types of school-based interventions have the greatest impact. The objective of this systematic review is to assess the impact and design of school-based PA interventions targeting adolescent girls. A systematic search was conducted using four electronic databases (PubMed, Web of Science, SPORTDiscus and PsychInfo). This systematic review was registered with PROSPERO (Registration number: CRD42016037428) and PRISMA guidelines (2009) were followed throughout. Twenty studies were identified as meeting the inclusion criteria and were included in a narrative synthesis. Seventeen studies were eligible for inclusion in a meta-analysis. There was a significant small positive treatment effect for school-based PA interventions for adolescent girls (k = 17, g = 0.37, p < 0.05). After an outlier was removed (residual z = 7.61) the average treatment effect was significantly reduced, indicating a very small positive effect (k = 16, g = 0.07, p = 0.05). Subgroup analysis revealed very small significant effects for multi-component interventions (k = 7, g = 0.09, p < 0.05), interventions underpinned by theory (k = 12, g = 0.07, p < 0.05), and studies with a higher risk of bias (k = 13, g = 0.09, p < 0.05). Intervention effects were very small which indicates that changing PA behaviors in adolescent girls through school-based interventions is challenging. Multi-component interventions and interventions underpinned by theory may be the most effective approaches to positively change adolescent girls' PA

A non-equivalent group pilot trial of a school-based physical activity and fitness intervention for 10–11 year old english children: born to move

Background: PE lessons are the formal opportunity in schools for promotion of physical activity and fitness. This study aimed to evaluate the effectiveness of a pilot PE intervention on physical activity, fitness, and psychosocial outcomes. Methods: Participants were 139 children aged 10–11 years from four schools. For six weeks children in two schools received a twice-weekly pilot ‘Born to Move’ (BTM) physical activity (PA) and fitness intervention alongside one regular PE lesson. Children in the two comparison (COM) schools received their regular twice weekly PE lessons. Outcomes were lesson time and whole-day light (LPA), moderate (MPA), vigorous (VPA), and MVPA, and sedentary time, muscular fitness, cardiorespiratory fitness (CRF), and lesson-specific perceived exertion, enjoyment, and perceived competence. Outcomes were assessed at baseline (T0), midway through the intervention (T1), and at the end (T2) using ANOVAs and ANCOVAs. Intervention fidelity was measured using child and teacher surveys at T2 and analysed using Chi-square tests. Results: The BTM group engaged in moderate PA for significantly more lesson time (29.4 %) than the COM group (25.8 %; p = .009, d = .53). The amount of moderate-to-vigorous PA (MVPA) during the T1 BTM lesson contributed 14.0 % to total MVPA, which was significantly more than the COM group’s T1 PE lesson (11.4 %; p < .001, d = .47). The BTM group were significantly more active during the whole-day (p < .05) and the school-day (p < .01). In both groups push-up test performance increased (p < .001) and CRF test performance decreased (p < .01). Perceived exertion, enjoyment, and perceived competence increased in both groups (p < .05), but the BTM group rated their enjoyment of the T1 BTM lesson higher than the COM group rated their PE lesson (p = .02, d = .56). The children’s and teachers’ responses to the intervention indicated that the delivery aims of enjoyment, engagement, inclusivity, and challenge were satisfied. Conclusions: The BTM pilot programme has potential to positively impact on physical activity, fitness, and psychosocial outcomes. Further, BTM was enjoyed by the children, and valued by the teachers. This study can inform the design of a modified larger-scale cluster RCT evaluation

Predictors of segmented school day physical activity and sedentary time in children from a northwest England low-income community

Background: Schools have been identified as important settings for health promotion through physical activity participation, particularly as children are insufficiently active for health. The aim of this study was to investigate the child and school-level influences on children0s physical activity levels and sedentary time during school hours in a sample of children from a low-income community; Methods: One hundred and eighty-six children (110 boys) aged 9–10 years wore accelerometers for 7 days, with 169 meeting the inclusion criteria of 16 h day1 for a minimum of three week days. Multilevel prediction models were constructed to identify significant predictors of sedentary time, light, and moderate to vigorous physical activity during school hour segments. Child-level predictors (sex, weight status, maturity offset, cardiorespiratory fitness, physical activity self-efficacy, physical activity enjoyment) and school-level predictors (number on roll, playground area, provision score) were entered into the models; Results: Maturity offset, fitness, weight status, waist circumference-to-height ratio, sedentary time, moderate to vigorous physical activity, number of children on roll and playground area significantly predicted physical activity and sedentary time; Conclusions: Research should move towards considering context-specific physical activity and its correlates to better inform intervention strategies

Acceptability and feasibility of single-component primary school physical activity interventions to inform the AS:Sk project

Multi-component school-based interventions provide physical activity (PA) opportunities for children but are often difficult for schools to execute and may not be implemented as intended. The primary aim of this study was to explore the acceptability and feasibility of three brief single component primary school PA interventions targeting 9–10-year-old children. The secondary aim was to examine the effectiveness of the interventions on increasing PA levels and reducing sedentary time. The single-component interventions included active classroom breaks (AB; 3 schools; n = 119 children) Born to Move (BTM) exercise videos (2 schools; n = 50 children), and playground supervisory staff training (2 schools; n = 56 children). Qualitative data from participating children (n = 211), class teachers (n = 6), and playground supervisory staff (n = 8) explored the experiences, acceptability, and feasibility of each intervention component. Accelerometers were worn by 225 children during the last week of implementation. Teachers reported that they were able to implement ABs daily, but BTM videos were more difficult to implement daily because of accessing sufficient space. Playground staff reported difficulties in implementing activities due to children’s age and competing responsibilities on the staffs’ time. Children reported that the ABs and BTM videos were enjoyable. During half hour time windows, including the ABs and BTM videos, children engaged in 4.8 min and 8.6 min of moderate to vigorous PA (MVPA) on average, respectively. ABs and BTM videos positively affected MVPA. ABs were feasible to implement; however, teachers faced some barriers in implementing the BTM videos. Feasibility of playground interventions may be dependent on staff responsibilities and age of the children

The feasibility of a novel school peer-led mentoring model to improve the physical activity levels and sedentary time of adolescent girls: the girls peer activity (G-PACT) project

Regular physical activity (PA) is associated with numerous physical and psychological health benefits. Adolescents, specifically girls, are at risk of physical inactivity. To date, there is limited research on PA interventions involving peers, which could encourage more adolescent girls to engage in PA. The investigation aimed to evaluate the feasibility of a novel school three-tier peer-led mentoring model designed to improve PA levels and reduce sedentary time (ST) of adolescent girls. Two-hundred and forty-nine Year 9 adolescent girls (13–15 years old) from three UK secondary schools were invited to participate in a peer-led mentoring intervention (Girls Peer Activity (G-PACT) project). The peer-led mentoring model was delivered in all three schools. Two of the schools received an additional after-school PA component. PA and ST were assessed through wrist-worn accelerometry. Girls who received an exercise class after-school component significantly increased their whole day moderate-to-vigorous PA (MVPA) (3.2 min, p = 0.009, d = 0.33). Girls who received no after-school component significantly decreased their MVPA (3.5 min, p = 0.016, d = 0.36) and increased their ST (17.2 min, p = 0.006, d = 0.43). The G-PACT intervention demonstrated feasibility of recruitment and data collection procedures for adolescent girls. The peer-led mentoring model shows promise for impacting girls’ MVPA levels when combined with an after-school club PA opportunity

Fitness, fatness and the reallocation of time between children’s daily movement behaviours: an analysis of compositional data

Background: Movement behaviours performed over a finite period such as a 24 h day are compositional data. Compositional data exist in a constrained simplex geometry that is incongruent with traditional multivariate analytical techniques. However, the expression of compositional data as log-ratio co-ordinate systems transfers them to the unconstrained real space, where standard multivariate statistics can be used. This study aimed to use a compositional data analysis approach to examine the adiposity and cardiorespiratory fitness predictions of time reallocations between children’s daily movement behaviours. Methods: This study used cross-sectional data from the Active Schools: Skelmersdale study, which involved Year 5 children from a low-income community in northwest England (n = 169). Measures included accelerometer-derived 24 h activity (sedentary time [ST], light physical activity [LPA], moderate-to-vigorous physical activity [MVPA], and sleep), cardiorespiratory fitness determined by the 20 m shuttle run test, objectively measured height, weight and waist circumference (from which zBMI and percent waist circumference-to-height ratio (%WHtR) were derived) and sociodemographic covariates. Log-ratio multiple linear regression models were used to predict adiposity and fitness for the mean movement behaviour composition, and for new compositions where fixed durations of time had been reallocated from one behaviour to another, while the remaining behaviours were unchanged. Predictions were also made for reallocations of fixed durations of time using the mean composition of three different weight status categories (underweight, normal-weight, and overweight/obese) as the starting point. Results: Replacing MVPA with any other movement behaviour around the mean movement composition predicted higher adiposity and lower CRF. The log-ratio model predictions were asymmetrical: when time was reallocated to MVPA from sleep, ST, or LPA, the estimated detriments to fitness and adiposity were larger in magnitude than the estimated benefits of time reallocation from MVPA to sleep, ST or LPA. The greatest differences in fitness and fatness for reallocation of fixed duration of MVPA were predicted at the mean composition of overweight/obese children. Conclusions: Findings reinforce the key role of MVPA for children’s health. Reallocating time from ST and LPA to MVPA in children is advocated in school, home, and community settings