Effects of a specialist-led, school physical education program on bone mass, structure and strength in primary school children: a 4-year cluster randomised controlled trial

This 4-year cluster randomised controlled trial of 365 boys and 362 girls (mean age 8.1 ± 0.3 years) from grade 2 in 29 primary schools investigated the effects of a specialist-taught physical education (PE) program on bone strength and body composition. All children received 150 min/week of common practice (CP) PE from general classroom teachers but in 13 schools 100 min/week of CP PE was replaced by specialized-led PE (SPE) by teachers who emphasized more vigorous exercise/games combined with static and dynamic postural activities involving muscle strength. Outcome measures assessed in grades 2, 4, and 6 included: total body bone mineral content (BMC), lean mass (LM) and fat mass (FM) by DXA, and radius and tibia (4% and 66% sites) bone structure, volumetric density and strength, and muscle cross-sectional area (CSA) by pQCT. After 4-years, gains in total body BMC, FM and muscle CSA were similar between the groups in both sexes, but girls in the SPE group experienced a greater gain in total body LM [mean (95%CI), 1.0kg (0.2, 1.9)]. Compared to CP, girls in the SPE group also had greater gains in cortical area (CoA) and cortical thickness (CoTh) at the mid-tibia [CoA, 5.0% (0.2, 1.9); CoTh 7.5% (2.4, 12.6)] and mid-radius [CoA, 9.3% (3.5, 15.1); CoTh 14.4% (6.1, 22.7)], while SPE boys had a 5.2% (0.4, 10.0) greater gain in mid-tibia CoTh. These benefits were due to reduced endocortical expansion. There were no significant benefits of SPE on total bone area, cortical density or bone strength at the mid-shaft sites, nor any appreciable effects at the distal skeletal sites. This study indicates that a specialist-led school-based PE program improves cortical bone structure, due to reduced endocortical expansion. This finding challenges the notion that periosteal apposition is the predominant response of bone to loading during the pre- and early-pubertal period. This article is protected by copyright. All rights reserved.

A systematic review of how researchers characterize the school environment in determining its effect on student obesity

BACKGROUND: Obesity in early childhood is a robust predictor of obesity later in life. Schools provide unparalleled access to children and have subsequently become major intervention sites. However, empirical evidence supporting the effectiveness of school-based interventions against childhood obesity is of limited scope and unknown quality. The aim of this systematic review is to critically assess how researchers have characterized the school environment in determining its effect on childhood weight status in order to improve the quality and consistency of research in this area. We conducted a narrative review with a systematic search of the literature in line with PRISMA guidelines (2009). Original peer-reviewed research articles in English were searched from Medline, EMBASE, CENTRAL, CINAHL and PsycINFO databases from earliest record to January 2014. We included empirical research that reported at least one measure of the primary/elementary school environment and its relationship with at least one objective adiposity-related variable for students aged 4-12 years. Two authors independently extracted data on study design, school-level factors, student weight status, type of analysis and effect. RESULTS: Five studies met the inclusion criteria. Each study targeted different parts of the school environment and findings across the studies were not comparable. The instruments used to collect school-level data report no validity or reliability testing. CONCLUSIONS: Our review shows that researchers have used instruments of unknown quality to test if the school environment is a determinant of childhood obesity, which raises broader questions about the impact that schools can play in obesity prevention.

Lesson study - Could it work for you?

1. Introduction Japanese Lesson Study first came to world-wide attention through Makoto Yoshida’s doctoral dissertation (Yoshida, 1999; Fernandez & Yoshida, 2004) and Stigler and Hiebert’s (1999) accounts of Lesson Study based on the Third International Mathematics and Science Study (TIMSS). By 2004, Lesson Study was taking place in the USA in at least 32 states and 150 lesson study clusters.Lewis (2002) describes the Lesson Study Cycle as having four phases: goal-setting and planning – including the development of the Lesson Plan; teaching the “research lesson” – enabling the lesson observation; the post-lesson discussion; and the resulting consolidation of learning, which has many far-reaching consequences (see, for example, Lewis & Tsuchida, 1998). It could be said that research lessons make participants and observers think quite profoundly about specific and general aspects of teaching.In Japan, Lesson Study occurs across many curriculum areas, mainly at the elementary school level, and to a lesser extent junior secondary. In mathematics, the research lesson usually follows the typical lesson pattern for a Japanese “structured problem solving lesson”.Major characteristics of such lessons include: the hatsumon – the thought-provoking question or problem that students engage with and that is the key to students’ mathematical development and mathematical connections; kikan-shido – sometimes referred to as the “purposeful scanning” that takes place while students are working individually or in groups, which allows teachers not only to monitor students’ strategies but also to orchestrate their reports on their solutions in the neriage phase of the lesson; neriage – the “kneading” stage of alesson that allows students to compare, polish and refine solutions through the teacher’s orchestration and probing of student solutions; and matome — the summing up and careful review of students’ discussion in order to guide them to higher levels of mathematical sophistication (see, for example, Shimizu, 1999).