The macro-policies and micropolitics influencing pre-service secondary school physical education teachers’ interpretations of pedagogy, when using a gymnastics interactive mobile website at one university in England

This study reports on the use of a purposefully designed bespoke mobile website, as part of a gymnastics module of work (10 weeks), on a Post Graduate Certificate of Education course in 2014. This involved 23 (f = 13 / m = 10) secondary physical education (PE) pre-service teachers, a teacher educator (female) and me (researcher, website designer and teacher educator). Additionally, a pilot study was conducted in 2013 (2 weeks), involving 24 PE pre-service teachers, with the aim of testing the mobile website’s usability. The intent of the mobile website was to support the development of pedagogical content knowledge and constructivist pedagogies of PE pre-service teachers, as they learnt to teach gymnastics. [Continues.

Associations of objectively and subjectively measured physical activity with trabecular and cortical bone properties in prepubertal children

Objectives. To compare the relationship between peak bone strain scores (PBSSs) calculated from physical activity (PA) questionnaires and accelerometry measures of PA with trabecular and cortical bone properties in prepubertal children. Methods. We compared PBSSs calculated from the bone-specific component of PA questionnaires with accelerometry and bone mass measures in 38 prepubertal children (mean 9.9 (standard deviation 1.3) years). Dual energy X-ray absorptiometry (DXA) and peripheral quantitative computed tomography (pQCT) were used to assess bone content and structure, and to estimate bone strength at the radial and tibial diaphysis and radial metaphysis. Results. The PBSS was reliable and reproducible with significant (p<0.001) intraclass correlation coefficients. There were significant correlations between PBSS and moderate (r=0.38; p=0.02), vigorous (r=0.36; p=0.03) and combined moderate- to vigorous-intensity activity counts (r=0.38; p=0.02). PBSS was significantly correlated to body size-adjusted bone mineral content at all sites scanned by DXA (r=0.33 - 0.48; p<0.05). Positive correlations were observed between PBSS and area, density and strength at the radius and tibia (r=0.40 - 0.64; p<0.05). Only vigorous activity was correlated to cortical area at the radial diaphysis (r=0.37; p=0.03) and bone strength at the tibial diaphysis (r=0.32; p=0.05). Activity as assessed by the PBSS explained a greater amount of variance in bone variables as measured by DXA and pQCT than accelerometer-measured PA. Conclusion. Accelerometer-measured moderate and vigorous habitual PA is associated with indices of cortical bone size and geometry in children, whereas light PA has no detectable association. Furthermore, the bone-specific questionnaire appears to be more strongly associated with bone outcomes than accelerometer-derived measures of PA

The Positive Psychology of Maritime Health

The remote, isolated, confined, and safety-critical environment of seafaring exposes seafarers to a very specific assortment of stressors. Research suggests that seafarers as a professional group are amongst those at high risk for stress and associated mental health conditions. This article explores positive psychology as an approach to supporting wellbeing at sea. Positive psychology may support health, positive attitudes and productive work behaviour; however it cannot and should not be employed as a means of inoculating seafarers against the negative consequences of fundamentally unreasonable work practices. Rather, positive psychology can help seafarers thrive in an overall context that recognises and enacts the benefits of a positive and reasonable work environment. Recommendations are made for future research regarding online or computer-based positive psychology interventions and training, and research on maritime health at the systems level

The Positive Psychology of Maritime Health

The remote, isolated, confined, and safety-critical environment of seafaring exposes seafarers to a very specific assortment of stressors. Research suggests that seafarers as a professional group are amongst those at high risk for stress and associated mental health conditions. This article explores positive psychology as an approach to supporting wellbeing at sea. Positive psychology may support health, positive attitudes and productive work behaviour; however it cannot and should not be employed as a means of inoculating seafarers against the negative consequences of fundamentally unreasonable work practices. Rather, positive psychology can help seafarers thrive in an overall context that recognises and enacts the benefits of a positive and reasonable work environment. Recommendations are made for future research regarding online or computer-based positive psychology interventions and training, and research on maritime health at the systems level

Comparison of Compliance and Intervention Outcomes Between Hip- and Wrist-Worn Accelerometers During a Randomised Crossover Trial of an Active Video Game Intervention in Children.

Background: There are several practical issues when considering the use of hip-worn or wrist-worn accelerometers. This study compared compliance and outcomes between hip- and wrist-worn accelerometers worn simultaneously by children during an active video games intervention. Methods: As part of a larger randomized crossover trial, participants (n=73, age 10-12 years) wore 2 Actical accelerometers simultaneously during waking hours for 7 days, on the hip and wrist. Measurements were repeated at 4 timepoints: 1) at baseline, 2) during traditional video games condition 3) during active video games condition 4) during no video games condition. Compliance and intervention effects were compared between hip and wrist. Results: There were no statistically significant differences at any timepoint in percentage compliance between hip (77-87%) and wrist (79-89%). Wrist-measured counts (difference of 64.3 counts per minute, 95% CI 4.4, 124.3) and moderate-to-vigorous physical activity (MVPA) (12 min/day, 95% CI 0.3, 23.7) were higher during the no video games condition compared to the traditional video games condition. There were no differences in hip-measured counts per minute or MVPA between conditions or sedentary time for hip or wrist. Conclusions: There were no differences in compliance between hip- and wrist-worn accelerometers during an intervention trial, however, intervention findings differed between hip and wrist

The association of environmental and lifestyle factors with bone mass acquisition in South African children by sex, race and age

While osteoporosis is a major public health concern in the developed world, little research regarding factors influencing bone mineral accrual in children has been conducted in developing countries. South Africa is of particular interest since the incidence of hip fractures in South African Blacks has been reported to be amongst the lowest in the world (32; 253). In this thesis, the association of lifestyle factors; in particular physical activity (PA), socio economic status (SES) and dietary calcium intakes on the growing skeleton of Black and White South African children is investigated. After using accelerometry to validate a physical activity questionnaire (PAQ), in a convenience sample of South African Black, White, male and female children (n=30), fitness levels were assessed in a larger group (n=69) of similarly aged children, stratified by race and gender. Fittest subjects had significantly greater physical activity scores (p=0.022) as reported on the PAQ, lower body mass index’s (BMI) (p=0.001) and least percentage body fat (p=0.001) (as assessed using Dual Energy X-ray Absorptiometry (DXA), than least fit subjects. White males who reported to be significantly more active than all other groups on the PAQ were significantly fitter (p<0.001) than White females and Black males and females. The next study sought to determine whether differences observed in physical activity levels between groups showed an association with bone mineral content (BMC), density (BMD) and area (BA) (as assessed using DXA). PA was analyzed in terms of a metabolic (METPA; weighted metabolic score of intensity, frequency, and duration) and a mechanical (MECHPA;sum of all ground reaction forces multiplied by duration) component for 386 children aged 9.5 (0.04) years recruited from a longitudinal birth cohort study. White children expended a significantly greater energy score (METPA of 21.7 (2.9)) than Black children (METPA of 9.5 (0.5), p< 0.001). When children were divided into quartiles according to the amount and intensity of sport played, the most active White children had significantly higher (p<0.05) whole body BMD and higher hip and spine BMC and BMD after adjustment for body size than less active children. White children in the highest MECHPA quartile also showed significantly higher (p<0.05) whole body, hip, and spine BMC and BMD after adjustment for body size than those children in the lowest quartile. No association between PA and bone mass of Black children was found. No significant differences between METPA and MECHPA quartiles and BA were observed for any group. Given the disparate backgrounds from which many South African children come, the next study sought to determine whether differences in socio-economic status between Black and White South African children influence PA patterns. This study explored the relationship between socio-economic status, PA anthropometric and body composition (via DXA) variables in 381 children aged (9.5 (0.04) years) recruited from a longitudinal birth cohort study . Children falling into the highest socio-economic status quartile had mothers with the highest educational levels, generally came from dual parent homes, were most physically active, watched less television, weighed more and had greater lean tissue than children in lower socio-economic quartiles (p<0.001). Significantly greater levels of lean mass (p<0.001) with increased activity level were observed after controlling for television watching time and fat mass. There were high levels of low physical activity and high television watching time among lower socio-economic status groups. White children were found to be more active than Black children, more likely to be offered physical education and to participate in physical education classes at school and watched less television than Black children. The final study sought to investigate the association between habitual PA patterns and dietary calcium intakes with bone mass acquisition over a one year period in 321 pre-pubertal South African children recruited from a longitudinal birth cohort study. Data were analyzed by regressing change in BMC and BA from age nine to ten years, against BA (for BMC), height and body weight. The residuals were saved and called residualized BMCGAIN and BAGAIN. Residualized values provide a good indication of weight, height and BA-matched accumulation rates. White children had significantly higher PA levels and calcium intakes than Black children. Most active White males had significantly higher residualized BMCGAIN and BAGAIN at the whole body, hip and spine but not at the radius, than those who were less active. Most active White females had significantly higher residualized BAGAIN at all sites except the radius than less-active girls. No such effects were seen in Black children. There was no interactive effect on residualized BMCGAIN or BAGAIN for calcium intake and PA in boys or Black girls, but an interactive and possible synergistic effect of calcium and physical activity was observed at the spine, radius and hip in White girls. In this population, PA has an osteogenic association with White children, but not Black children, which may be explained by the lower levels of PA in the Black children. Despite this, Black children had significantly greater bone mass at the hip and spine (girls only) (p< 0.001) even after adjustment for body size.In conclusion, differences between White and Black children’s PA levels were observed, with White children reporting higher PA levels and exhibiting higher fitness levels than Black children. Physical fitness correlated well with self reported physical activity levels on the PAQ and objectively measured body composition. Socio-economic status differences between White and Black children are highly related to differences in physical activity patterns and body composition profiles. Bone mass and area gain is accentuated in pre- and early-pubertal children with highest levels of habitual physical activity. Limited evidence of an effect of dietary calcium intakes on bone mass in boys and Black girls was found. The role of exercise in increasing bone mass may become increasingly critical as a protective mechanism against osteoporosis in both South African race groups, especially because the genetic benefit exhibited by Black children to higher bone mass may be weakened with time, as environmental influences become stronger

Trajectories of television watching from childhood to early adulthood and their association with body composition and mental health outcomes in young adults

Introduction: Prior studies examining longitudinal patterns of television (TV) watching have tended to use analytical approaches which do not allow for heterogeneity in the variation of TV watching over time. In the current study, we used latent class analysis (LCA) to examine the relationships between television watching (from childhood to early adulthood) and body fat percentage (%) and mental health. Methods: Data were collected from 2411 participants (50% female) from the Raine Study, a prospective birth cohort study in Australia. Participants were followed up over 15 years and answered questions about hours of TV watching per week at six time-points (5, 8, 10, 14, 17 and 20yrs). Trajectories of television watching were estimated using LCA and appropriate regression models used to test the association of television watching class with percentage body fat (measured by DXA) and mental health (DASS-21) at age 20. Physical activity was used as a covariate. Results: Three distinct trajectories of TV watching were identified. Class 1 (47.4%) had consistently high (>14 hrs/wk) levels of TV watching, Class 2 (37.9%) was characterised by an increase in TV watching over adolescence and Class 3 (14.7%) had consistently lower (0.05). Conclusions: TV watching from childhood to young adulthood appears to be a relatively stable behaviour for around two thirds of participants, but not everyone tracks consistently. This study identified a subset of participants with low levels of TV watching in childhood and also that this group, despite an increase in TV watching over adolescence, maintained a lower level of body fat in young adulthood

It's A-bout Time: Detailed Patterns of Physical Activity in Obese Adolescents Participating in a Lifestyle Intervention.

BACKGROUND: The detailed patterns of physical activity and sedentary behaviors of overweight and obese adolescents are unknown, but may be important for health outcomes and targeted intervention design. METHODS: Participants completed Curtin University's Activity, Food and Attitudes Program (CAFAP), an 8-week intervention with 12 months of maintenance intervention. Physical activity and sedentary time were assessed at 6 time periods with accelerometers and were analysed by 1) time and type of day 2) intensity bout patterns using exposure variation analysis, and 3) individual case analysis. RESULTS: Participants (n=56) spent a lower percentage of time at baseline in light activity during school days compared to weekend days (24.4% vs 29.0%, p=.004). The majority of time was in long uninterrupted sedentary bouts of greater than 30 minutes (26.7% of total time, 36.8% of sedentary time at baseline). Moderate activity was accumulated in short bouts of less than 5 minutes (3.1% of total time, 76.0% moderate time). Changes varied by individuals. CONCLUSIONS: Exposure variation analysis revealed specific changes in activity patterns in overweight and obese adolescents who participated in a lifestyle intervention. A better understanding of these patterns can help to design interventions that meaningfully affect specific behaviors, with unique health consequences