Post natal expression of Prx1 labels appendicular restricted progenitor cell populations of multiple tissues.

Currently, there is no consensus whether there is a single or multiple postnatal stem cell population(s) that contribute to skeletal homeostasis and postnatal bone formation. A known population of cells that express Prx1 contributes to postnatal bone formation. Prx1 expression also connotes calvaria and appendicular tissues during embryonic development. A transgenic tamoxifen inducible Prx1 reporter mouse was used for lineage tracking, to characterize the postnatal contribution of Prx1 expressing cells in skeletal homeostasis and bone formation. Under homeostatic conditions Prx1 labeling gave rise to a transient yet rapid turnover cell population at the periosteal and endosteal surfaces, along muscle fibers, and within the medial layers of vessels both within the muscle and marrow compartments of the appendicular skeleton. Fracture and ectopic bone formation of both fore and hind limbs showed recruitment and expansion of Prx1-derived cells in newly formed bone tissues. Prx1 labeled cells were limited or absent at axial skeletal sites during both homeostasis and after induction of bone formation. Last, Prx1-derived cells differentiated into multiple cell lineages including vascular smooth muscle, adipose, cartilage, and bone cells. These results show that Prx1 expression retained its embryonic tissue specification and connotes a stem/progenitor cell populations of mesenchymal tissue progenitors.

Co-participation in physical activity: perspectives from Australian parents of pre-schoolers.

Co-participation in physical activity may be important for helping families with young children meet physical activity recommendations. Yet, little is known about what families perceive to be the benefits, barriers and facilitators of co-participation. This study explored (i) parents' perceptions about physical activity and possible benefits of family-based co-participation in physical activity, (ii) their perceived facilitators and barriers to co-participation and (iii) their recommendations for improving co-participation within their community. Fifteen parents (14 mothers, 1 father) of 2- to 4-year-old children residing in Western Sydney, Australia, participated in one-on-one interviews between September 2016 and January 2017. Interviews were audio-recorded and transcribed verbatim. Four main themes and seven sub-themes emerged from the thematic analysis of the interview data. When parents were asked to reflect on their understanding of physical activity, they discussed a range of well-known activities (e.g. active play, active transport) and also reported 'anything but screen time'. The major benefits parents reported about co-participation were spending quality time together, improving children's general health and well-being and the development of physical skills. Social (e.g. social networks, negative stereotypes) and environmental (e.g. home space, neighbourhood design, shading) facilitators and barriers were identified, yet their impact on co-participation often varied depending on the presence (or lack thereof) of other factors in the physical or social environment. Key recommendations suggested by parents included improvements to home outdoor spaces, neighbourhood design and play spaces and community services.

An internet-supported school physical activity intervention in low socioeconomic status communities: results from the Activity and Motivation in Physical Education (AMPED) cluster randomised controlled trial.

OBJECTIVE: Quality physical education (PE) is the cornerstone of comprehensive school physical activity (PA) promotion programmes. We tested the efficacy of a teacher professional learning intervention, delivered partially via the internet, designed to maximise opportunities for students to be active during PE lessons and enhance adolescents' motivation towards PE and PA. METHODS: A two-arm cluster randomised controlled trial with teachers and Grade 8 students from secondary schools in low socioeconomic areas of Western Sydney, Australia. The Activity and Motivation in Physical Education (AMPED) intervention for secondary school PE teachers included workshops, online learning, implementation tasks and mentoring sessions. The primary outcome was the proportion of PE lesson time that students spent in moderate-to-vigorous physical activity (MVPA), measured by accelerometers at baseline, postintervention (7-8 months after baseline) and maintenance (14-15 months). Secondary outcomes included observed PE teachers' behaviour during lessons, students' leisure-time PA and students' motivation. RESULTS: Students (n=1421) from 14 schools completed baseline assessments and were included in linear mixed model analyses. The intervention had positive effects on students' MVPA during lessons. At postintervention, the adjusted mean difference in the proportion of lesson time spent in MVPA was 5.58% (p<0.001, approximately 4 min/lesson). During the maintenance phase, this effect was 2.64% (p<0.001, approximately 2 min/lesson). The intervention had positive effects on teachers' behaviour, but did not impact students' motivation. CONCLUSIONS: AMPED produced modest improvements in MVPA and compares favourably with previous interventions delivered exclusively face-to-face. Online teacher training could help facilitate widespread dissemination of professional learning interventions. TRIAL REGISTRATION NUMBER: ACTRN12614000184673.

An Internet-supported Physical Activity Intervention Delivered in Secondary Schools Located in Low Socio-economic Status Communities: Study Protocol for the Activity and Motivation in Physical Education (AMPED) Cluster Randomized Controlled Trial.

BACKGROUND: School-based physical education is an important public health initiative as it has the potential to provide students with regular opportunities to participate in moderate-to-vigorous physical activity (MVPA). Unfortunately, in many physical education lessons students do not engage in sufficient MVPA to achieve health benefits. In this trial we will test the efficacy of a teacher professional development intervention, delivered partially via the Internet, on secondary school students' MVPA during physical education lessons. Teaching strategies covered in this training are designed to (i) maximize opportunities for students to be physically active during lessons and (ii) enhance students' autonomous motivation towards physical activity. METHOD: A two-arm cluster randomized controlled trial with allocation at the school level (intervention vs. usual care control). Teachers and Year 8 students in government-funded secondary schools in low socio-economic areas of the Western Sydney region of Australia will be eligible to participate. During the main portion of the intervention (6 months), teachers will participate in two workshops and complete two implementation tasks at their school. Implementation tasks will involve video-based self-reflection via the project's Web 2.0 platform and an individualized feedback meeting with a project mentor. Each intervention school will also complete two group peer-mentoring sessions at their school (one per term) in which they will discuss implementation with members of their school physical education staff. In the booster period (3 months), teachers will complete a half-day workshop at their school, plus one online implementation task, and a group mentoring session at their school. Throughout the entire intervention period (main intervention plus booster period), teachers will have access to online resources. Data collection will include baseline, post-intervention (7-8 months after baseline) and maintenance phase (14-15 months after baseline) assessments. Research assistants blinded to group allocation will collect all data. The primary outcome will be the proportion of physical education lesson time that students spend in MVPA. Secondary outcomes will include leisure-time physical activity, subjective well-being, and motivation towards physical activity. DISCUSSION: The provision of an online training platform for teachers could help facilitate more widespread dissemination of evidence-based interventions compared with programs that rely exclusively on face-to-face training. TRIAL REGISTRATION: Australia and New Zealand Clinical Trials Registry- ACTRN12614000184673 . Registration date: February 19, 2014.

Scaling-up an efficacious school-based physical activity intervention: Study protocol for the 'Internet-based Professional Learning to help teachers support Activity in Youth' (iPLAY) cluster randomized controlled trial and scale-up implementation evaluation.

BACKGROUND: Despite the health benefits of regular physical activity, most children are insufficiently active. Schools are ideally placed to promote physical activity; however, many do not provide children with sufficient in-school activity or ensure they have the skills and motivation to be active beyond the school setting. The aim of this project is to modify, scale up and evaluate the effectiveness of an intervention previously shown to be efficacious in improving children's physical activity, fundamental movement skills and cardiorespiratory fitness. The 'Internet-based Professional Learning to help teachers support Activity in Youth' (iPLAY) study will focus largely on online delivery to enhance translational capacity. METHODS/DESIGN: The intervention will be implemented at school and teacher levels, and will include six components: (i) quality physical education and school sport, (ii) classroom movement breaks, (iii) physically active homework, (iv) active playgrounds, (v) community physical activity links and (vi) parent/caregiver engagement. Experienced physical education teachers will deliver professional learning workshops and follow-up, individualized mentoring to primary teachers (i.e., Kindergarten - Year 6). These activities will be supported by online learning and resources. Teachers will then deliver the iPLAY intervention components in their schools. We will evaluate iPLAY in two complementary studies in primary schools across New South Wales (NSW), Australia. A cluster randomized controlled trial (RCT), involving a representative sample of 20 schools within NSW (1:1 allocation at the school level to intervention and attention control conditions), will assess effectiveness and cost-effectiveness at 12 and 24 months. Students' cardiorespiratory fitness will be the primary outcome in this trial. Key secondary outcomes will include students' moderate-to-vigorous physical activity (via accelerometers), fundamental movement skill proficiency, enjoyment of physical education and sport, cognitive control, performance on standardized tests of numeracy and literacy, and cost-effectiveness. A scale-up implementation study guided by the RE-AIM framework will evaluate the reach, effectiveness, adoption, implementation, and maintenance of the intervention when delivered in 160 primary schools in urban and regional areas of NSW. DISCUSSION: This project will provide the evidence and a framework for government to guide physical activity promotion throughout NSW primary schools and a potential model for adoption in other states and countries. TRIAL REGISTRATION: Australia and New Zealand Clinical Trials Registry ( ACTRN12616000731493 ). Date of registration: June 3, 2016.

A systematic review and meta-analysis of interventions designed to increase moderate-to-vigorous physical activity in school physical education lessons.

OBJECTIVES: Physical education (PE) that allows students to engage in moderate-to-vigorous physical activity (MVPA) can play an important role in health promotion. Unfortunately, MVPA levels in PE lessons are often very low. In this review, we aimed to determine the effectiveness of interventions designed to increase the proportion of PE lesson time that students spend in MVPA. METHODS: In March 2012, we searched electronic databases for intervention studies that were conducted in primary or secondary schools and measured the proportion of lesson time students spent in MVPA. We assessed risk of bias, extracted data, and conducted meta-analyses to determine intervention effectiveness. RESULTS: From an initial pool of 12,124 non-duplicate records, 14 studies met the inclusion criteria. Students in intervention conditions spent 24% more lesson time in MVPA compared with students in usual practice conditions (standardized mean difference=0.62). CONCLUSIONS: Given the small number of studies, moderate-to-high risk of bias, and the heterogeneity of results, caution is warranted regarding the strength of available evidence. However, this review indicates that interventions can increase the proportion of time students spend in MVPA during PE lessons. As most children and adolescents participate in PE, these interventions could lead to substantial public health benefits.

A cluster randomized controlled trial of strategies to increase adolescents' physical activity and motivation in physical education: results of the Motivating Active Learning in Physical Education (MALP) trial.

OBJECTIVE: Physical education (PE) programs aim to promote physical activity (PA) and reach most school-aged youth. However, PA levels within PE lessons are often low. In this cluster-randomized controlled trial, we examined the effects of three self-determination theory-based motivational strategies on PA and sedentary behavior, as well as their hypothesized antecedents during PE lessons. METHODS: Data were collected in Sydney, Australia (October-December 2011). After baseline testing, teachers (n=16) and their classes (n=288 students; M=13.6 years, 50.4% male) were randomly assigned to one of four teaching strategy conditions: (1) explaining relevance; (2) providing choice; (3) complete free choice; or (4) usual practice. Teachers then delivered the assigned strategy. Primary outcomes were accelerometer-assessed PA and student motivation during lessons. Secondary outcomes included sedentary behavior, perceptions of teachers' support and psychological needs satisfaction. RESULTS: The 'free choice' intervention increased PA (p<.05). 'Providing choice' and 'free choice' interventions decreased sedentary behavior (p<.05). The interventions did not influence motivation, but students' autonomy increased during both choice-based interventions (p<.05). CONCLUSIONS: Promoting choice can produce short-term increases in PA and decreases in sedentary behavior, as well as increased perceived autonomy during PE lessons.

A cluster-randomized controlled trial of strategies to increase adolescents' physical activity and motivation during physical education lessons: the Motivating Active Learning in Physical Education (MALP) trial.

BACKGROUND: The physical activity (PA) levels of many children and adolescents in Australia are currently insufficient to promote health benefits. Physical education (PE) programs aim to promote PA and reach nearly all school-aged children, but PA levels within PE lessons are often low. PE teachers may influence children's motivation to be physically active in PE lessons, but little is known about teacher strategies that effectively motivate children to participate in PA, and few intervention studies have examined motivational strategies in PE. The purpose of this study was to compare the effect of three motivational strategies, each based on Self-Determination Theory (SDT), on PA levels, and their hypothesized antecedents, during year 8 PE lessons. METHODS/DESIGN: This study employed a cluster-randomized controlled trial design. Following a familiarization session, PA levels and hypothesized PA antecedents were measured during a baseline lesson and a post-intervention or control lesson. Teachers (n = 16) and their classes from five secondary schools in Sydney, Australia were randomly assigned into four blocks and instructed to provide one of four 20-min lesson teaching strategy conditions: (1) explaining the relevance of activities; (2) providing choice from PA options selected by the teacher; (3) providing equipment and free choice of activities; or (4) usual practice. The primary outcomes were lesson time spent in moderate-to-vigorous PA, and motivation towards the lesson. Secondary outcomes were perceptions of teacher behavior, psychological needs satisfaction, and lesson time spent in sedentary behavior. PA and sedentary behavior were measured during baseline and post-intervention lessons with waist-mounted Actigraph GT3X accelerometers. Teacher behavior, psychological needs satisfaction, and motivation were assessed via questionnaires at the end of each lesson. Linear mixed-model analyses will be run on all outcomes, with students nested within teachers as a random effect. DISCUSSION: Study findings will inform the development of effective SDT-based teaching strategy interventions to enhance students' psychological needs satisfaction, motivation, and PA levels. More effective teaching strategies may be identified that are capable of improving adolescents' PA levels, and thereby provide beneficial population health outcomes. TRIAL REGISTRATION: This trial is registered with Current Controlled Trials and is traceable as ISRCTN07038258.

Effectiveness of Adult Health Promotion Interventions Delivered Through Professional Sport: Systematic Review and Meta-Analysis.

BACKGROUND: Researchers are capitalising on the strong connections that sport fans have with their teams for health promotion programmes, yet no existing systematic reviews have evaluated the effectiveness of interventions delivered through professional sport. OBJECTIVE: The aim of this study was to systematically collate, evaluate, and synthesise the evidence on health promotion interventions implemented in professional sport settings. METHODS: Randomised controlled trials reporting on adult health promotion initiatives delivered in professional sport settings were identified through electronic database searches in CINAHL, MEDLINE, SPORTDiscus, Scopus, the Cochrane Central Register of Controlled Trials (CENTRAL), and Google Scholar. Data on health-related outcomes (e.g., weight, physical activity, dietary intake) were extracted and synthesised, and random effects meta-analyses were conducted to examine effects for weight and waist circumference. Risk of bias was examined using the Cochrane risk-of-bias tool for randomised controlled trials (RoB 2). RESULTS: Six studies reporting on five unique interventions met the inclusion criteria, and all included studies were gender-sensitised and exclusively targeted men. Intervention effects were observed for several health outcomes, including physical activity, dietary intake, and psychosocial health. All studies aimed to reduce weight, and for most studies (n = 4), weight was a primary outcome, either of the included study or to inform a future definitive trial. Findings from the meta-analysis revealed an overall significant difference in change in weight of - 3.2 kg (95% confidence interval [CI] - 4.6 to - 1.8) and waist circumference of - 3.9 cm (95% CI - 4.9 to - 2.8), both in favour of the intervention group at 12 weeks. Intervention effects were also reported for several other health outcomes (e.g., physical activity, dietary intake, psychosocial health); however, they were not consistently measured across the studies and thus were not meta-analysed. CONCLUSION: Health promotion interventions delivered through professional sporting organisations can significantly improve weight- and lifestyle-related health outcomes. Representation across the socioeconomic spectrum and across culturally and linguistically diverse groups was limited. As only a limited number of studies met the inclusion criteria for this review, a need exists for rigorously designed interventions, standardised intervention approaches, with long-term follow-up, and the potential for scalability. PROSPERO REGISTRATION NUMBER: CRD42019123295.

Exploring the Experiences and Well-Being of Australian Rio Olympians During the Post-Olympic Phase: A Qualitative Study.

Research about the Olympic Games has primarily focused on preparing athletes for competition. Less attention has been paid to the post-Olympic-phase (POP) and athlete well-being during this time. This study explored Australian Olympic athletes' experiences following the conclusion of the 2016 Rio Olympic Games, including the factors that may have contributed to or challenged their well-being during this time. Eighteen athletes participated in semi-structured interviews and thematic analysis revealed that when Olympic performance appraisal met prior expectations, when athletes planned for a return to work or study, and when support from a variety of sources was readily available, this positively influenced athletes' well-being during the POP. When these factors were not in place, more challenging post-Games experiences were present, and well-being was compromised. The findings contribute to the broader literature on elite athlete well-being and at an applied level, may be used to inform targeted programs that focus on supporting athletes after an Olympic campaign.

Effect of a Scalable School-Based Intervention on Cardiorespiratory Fitness in Children: A Cluster Randomized Clinical Trial.

Importance: Cardiorespiratory fitness is an important marker of childhood health and low fitness levels are a risk factor for disease later in life. Levels of children's fitness have declined in recent decades. Whether school-based physical activity interventions can increase fitness at the population level remains unclear. Objective: To evaluate the effect of an internet-based intervention on children's cardiorespiratory fitness across a large number of schools. Design, Setting, and Participants: In this cluster randomized clinical trial, 22 government-funded elementary schools (from 137 providing consent) including 1188 students stratified from grades 3 and 4 in New South Wales, Australia, were randomized. The other schools received the intervention but were not included in the analysis. Eleven schools received the internet-based intervention and 11 received the control intervention. Recruitment and baseline testing began in 2016 and ended in 2017. Research assistants, blinded to treatment allocation, completed follow-up outcome assessments at 12 and 24 months. Data were analyzed from July to August 2020. Interventions: The internet-based intervention included standardized online learning for teachers and minimal in-person support from a project mentor (9-10 months). Main Outcomes and Measures: Multistage 20-m shuttle run test for cardiorespiratory fitness. Results: Of 1219 participants (49% girls; mean [SD] age, 8.85 [0.71] years) from 22 schools, 1188 students provided baseline primary outcome data. At 12 months, the number of 20-m shuttle runs increased by 3.32 laps (95% CI, 2.44-4.20 laps) in the intervention schools and 2.11 laps (95% CI, 1.38-2.85 laps) in the control schools (adjusted difference = 1.20 laps; 95% CI, 0.17-2.24 laps). By 24 months, the adjusted difference was 2.22 laps (95% CI, 0.89-3.55 laps). The cost per student was AUD33 (USD26). Conclusions and Relevance: In this study, a school-based intervention improved children's cardiorespiratory fitness when delivered in a large number of schools. The low cost and sustained effect over 24 months of the intervention suggests that it may have potential to be scaled at the population level. Trial Registration: http://anzctr.org.au Identifier: ACTRN12616000731493.

School Physical Activity Intervention Effect on Adolescents' Performance in Mathematics.

PURPOSE: The primary aim of this study was to test the effect of a school-based physical activity intervention on adolescents' performance in mathematics. A secondary aim was to explore potential mechanisms that might explain the intervention effect. METHODS: The Activity and Motivation in Physical EDucation intervention was evaluated using a two-arm cluster randomized controlled trial in 14 secondary schools located in low socioeconomic areas of Western Sydney, Australia. Study participants (n = 1173) were grade 8 students (mean age = 12.94 yr, SD = 0.54). The multicomponent intervention was designed to help teachers maximize students' opportunities for moderate-to-vigorous physical activity (MVPA) during physical education (PE) and enhance students' motivation toward PE. Mathematics performance was assessed as part of national testing in grade 7, which was the year before the trial began and then again in grade 9. Potential mediators were: (i) proportion of PE lesson time that students spent in MVPA and leisure time MVPA (%), measured using Actigraph GT3X+ accelerometers, and (ii) students' self-reported engagement (behavioral, emotional, and cognitive) during mathematics lessons. Mediators were assessed at baseline (grade 8) and follow-up (grade 9, 14-15 months after baseline). RESULTS: The effect of the intervention on mathematics performance was small-to-medium (ß = 0.16, P < 0.001). An intervention effect was observed for MVPA% in PE (ß = 0.59, P < 0.001), but not for leisure time MVPA or any of the engagement mediators. There were no significant associations between changes in potential mediators and mathematics performance. CONCLUSIONS: The Activity and Motivation in Physical EDucation intervention had a significant positive effect on mathematics performance in adolescents. However, findings should be interpreted with caution as the effect was small and not associated with changes in hypothesized mediators.

Do Natural Experiments of Changes in Neighborhood Built Environment Impact Physical Activity and Diet? A Systematic Review.

Physical activity and diet are major modifiable risk factors for chronic disease and have been shown to be associated with neighborhood built environment. Systematic review evidence from longitudinal studies on the impact of changing the built environment on physical activity and diet is currently lacking. A systematic review of natural experiments of neighborhood built environment was conducted. The aims of this systematic review were to summarize study characteristics, study quality, and impact of changes in neighborhood built environment on physical activity and diet outcomes among residents. Natural experiments of neighborhood built environment change, exploring longitudinal impacts on physical activity and/or diet in residents, were included. From five electronic databases, 2084 references were identified. A narrative synthesis was conducted, considering results in relation to study quality. Nineteen papers, reporting on 15 different exposures met inclusion criteria. Four studies included a comparison group and 11 were pre-post/longitudinal studies without a comparison group. Studies reported on the impact of redeveloping or introducing cycle and/or walking trails (n = 5), rail stops/lines (n = 4), supermarkets and farmers' markets (n = 4) and park and green space (n = 2). Eight/15 studies reported at least one beneficial change in physical activity, diet or another associated health outcome. Due to limitations in study design and reporting, as well as the wide array of outcome measures reported, drawing conclusions to inform policy was challenging. Future research should consider a consistent approach to measure the same outcomes (e.g., using measurement methods that collect comparable physical activity and diet outcome data), to allow for pooled analyses. Additionally, including comparison groups wherever possible and ensuring high quality reporting is essential.