Lisa S. Olive

Physical Education, Obesity, and Academic Achievement: A 2-Year Longitudinal Investigation of Australian Elementary School Children

OBJECTIVES We determined whether physical education (PE) taught by specialists contributed to academic development and prevention of obesity in elementary school children. METHODS Our 2-year longitudinal study involved 620 boys and girls initially in grade 3 in Australia, all receiving 150 minutes per week of PE. One group (specialist-taught PE; n = 312) included 90 minutes per week of PE from visiting specialists; the other (common-practice PE; n = 308) received all PE from generalist classroom teachers. Measurements included percentage of body fat (measured by dual-emission x-ray absorptiometry) and writing, numeracy, and reading proficiency (by government tests). RESULTS Compared with common-practice PE, specialist-taught PE was associated with a smaller increase in age-related percentage of body fat (P = .02). Specialist-taught PE was also associated with greater improvements in numeracy (P < .03) and writing (P = .13) scores. There was no evidence of a reading effect. CONCLUSIONS The attenuated age-related increases in percentage of body fat and enhanced numeracy development among elementary school children receiving PE from specialists provides support for the role of PE in both preventive medicine and academic development.

Why Are Girls Less Physically Active than Boys? Findings from the LOOK Longitudinal Study

Background A gender-based disparity in physical activity (PA) among youth, whereby girls are less active than boys is a persistent finding in the literature. A greater understanding of the mechanisms underlying this difference has potential to guide PA intervention strategies. Methods Data were collected at age 8 and 12 years (276 boys, 279 girls) from 29 schools as part of the LOOK study. Multilevel linear models were fitted separately for boys and girls to examine effects of individual, family and environmental level correlates on pedometer measured PA. Cardio-respiratory fitness (multi-stage run), percent fat (DEXA), eye-hand coordination (throw and catch test) and perceived competence in physical education (questionnaire) were used as individual level correlates. At the family level, parent’s support and education (questionnaire) were used. School attended and extracurricular sport participation were included as environmental level correlates. Results Girls were 19% less active than boys (9420 vs 11360 steps/day, p<0.001, 95%CI [1844, 2626]). Lower PA among girls was associated with weaker influences at the school and family levels and through lower participation in extracurricular sport. School attended explained some of the variation in boys PA (8.4%) but not girls. Girls compared to boys had less favourable individual attributes associated with PA at age 8 years, including 18% lower cardio-respiratory fitness (3.5 vs 4.2, p<0.001, CI [0.5,0.9]), 44% lower eye-hand coordination (11.0 vs 17.3, p<0.001, CI [5.1,9.0]), higher percent body fat (28% vs 23%, p<0.001, CI [3.5,5.7]) and 9% lower perceived competence in physical education (7.7 vs 8.4, p<0.001, CI [0.2,0.9]). Participation in extracurricular sport at either age 8 or 12 years was protective against declines in PA over time among boys but not girls. Conclusion Girls PA was less favourably influenced by socio-ecological factors at the individual, family, school and environmental levels. These factors are potentially modifiable suggesting the gap in PA between boys and girls can be reduced. Strategies aiming to increase PA should be multicomponent and take into consideration that pathways to increasing PA are likely to differ among boys and girls.

The influence of sport club participation on physical activity, fitness and body fat during childhood and adolescence: The LOOK Longitudinal Study

OBJECTIVES To investigate the longitudinal effect of sport participation in physical activity, fitness and body fat changes during childhood and adolescence. DESIGN Longitudinal study (134 boys, 155 girls) of Australian youth aged 8-16 years. METHODS Physical activity was assessed by pedometers and accelerometers, fitness by the 20m shuttle-run, body fat by DEXA and club sport participation by questionnaire. Linear mixed models were used to determine the effects of sport participation and gender differences. RESULTS Sports club participants were more physically active at all age groups than non-participants; boys took an extra 1800 steps (p<0.001) and girls 590 steps per day (p<0.01) and boys engaged in an extra 9min and girls 6min more moderate to vigorous PA per day (both p<0.05). Fitness was higher among sports participants (boys 27% and girls 20% higher, both p<0.001) and sport participant girls had 2.9% less body fat (p<0.05). Higher fitness scores were maintained over time by sports participants but their greater PA diminished during adolescence, this being more evident among girls. Only 20% of sports club participants met the recommended daily average of 60min MVPA. CONCLUSIONS Sport participants were more active, fitter and had less body fat (girls only) than non-sports participants. However, the associated benefits of sport with PA diminished during adolescence and the majority of sports participants did not meet recommended levels of PA. Strategies aiming to maximise the benefits of sports participation may be enhanced by providing special attention to the early adolescent period particularly among girls.

Physical Education and Blood Lipid Concentrations in Children: The LOOK Randomized Cluster Trial

Background and Objectives Elevated blood lipids during childhood are predictive of dyslipidemia in adults. Although obese and inactive children have elevated values, any potentially protective role of elementary school physical education is unknown. Our objective was to determine the effect of a modern elementary school physical education (PE) program on the blood lipid concentrations in community-based children. Methods In this cluster-randomized controlled trial, 708 healthy children (8.1±0.3 years, 367 boys) in 29 schools were allocated to either a 4-year intervention program of specialist-taught PE (13 schools) or to a control group of the currently practiced PE conducted by generalist classroom teachers. Fasting blood lipids were measured at ages 8, 10, and 12 years and intervention and control class activities were recorded. Results Intervention classes included more fitness work and more moderate and vigorous physical activity than control classes (both p<0.001). With no group differences at baseline, the percentage of 12 year-old boys and girls with elevated low density lipoprotein cholesterol (LDL-C, >3.36mmol.L−1,130 mg/dL) was lower in the intervention than control group (14% vs. 23%, p = 0.02). There was also an intervention effect on mean LDL-C across all boys (reduction of 9.6% for intervention v 2.8% control, p = 0.02), but not girls (p = 0.2). The intervention effect on total cholesterol mirrored LDL-C, but there were no detectable 4-year intervention effects on high-density lipoprotein cholesterol or triglycerides. Conclusions The PE program delivered by specialist teachers over four years in elementary school reduced the incidence of elevated LDL-C in boys and girls, and provides a means by which early preventative practices can be offered to all children. Trial Registration Australia New Zealand Clinical Trial Registry ANZRN12612000027819 https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=347799.

Physical education can improve insulin resistance: the LOOK randomized cluster trial.

PURPOSE As impaired glucose metabolism may arise progressively during childhood, we sought to determine whether the introduction of specialist-taught school physical education (PE) based on sound educational principles could improve insulin resistance (IR) in elementary school children. METHODS In this 4-yr cluster-randomized intervention study, participants were 367 boys and 341 girls (mean age = 8.1 yr, SD = 0.35) initially in grade 2 in 29 elementary schools situated in suburbs of similar socioeconomic status. In 13 schools, 100 min·wk-1 of PE, usually conducted by general classroom teachers, was replaced with two classes per week taught by visiting specialist PE teachers; the remaining schools formed the control group. Teacher and pupil behavior were recorded, and measurements in grades 2, 4, and 6 included fasting blood glucose and insulin to calculate the homeostatic model of IR, percent body fat, physical activity, fitness, and pubertal development. RESULTS On average, the intervention PE classes included more fitness work than the control PE classes (7 vs 1 min, P < 0.001) and more moderate physical activity (17 vs 10 min, P < 0.001). With no differences at baseline, by grade 6, the intervention had lowered IR by 14% (95% confidence interval = 1%-31%) in the boys and by 9% (95% confidence interval = 5%-26%) in the girls, and the percentage of children with IR greater than 3, a cutoff point for metabolic risk, was lower in the intervention than the control group (combined, 22% vs 31%, P = 0.03; boys, 12% vs 21%, P = 0.06; girls, 32% vs 40%, P = 0.05). CONCLUSIONS Specialist-taught primary school PE improved IR in community-based children, thereby offering a primordial preventative strategy that could be coordinated widely although a school-based approach.

Benefits of early development of eye–hand coordination: Evidence from the LOOK longitudinal study

We investigated longitudinal and cross‐sectional relationships between eye–hand coordination (EHC) and cardiorespiratory fitness (multistage run), physical activity (pedometers), percent body fat (%BF, dual energy x‐ray absorptiometry), body image, and organized sport participation (questionnaires) in 406 boys and 384 girls at 8 and 10 years of age. EHC was measured by a throw and wall‐rebound catch test involving 40 attempts of increasing difficulty. Median EHC improved during two years from 18 to 32 (boys) and 9 to 24 (girls), and gender differences and improvements were both significant (P < 0.001). Cross‐sectional analyses showed that boys and girls with better EHC were fitter (P < 0.001), and a longitudinal relationship showed that girls who improved their EHC over the two years became fitter (P < 0.001). There was also evidence that children with better EHC possessed a more positive body image (P = 0.05 for combined sex data), but there was no evidence of any relationships between EHC and %BF or PA (both P > 0.3). Finally, even at age 8 years, boys and girls participating in organized sport possessed better EHC than non‐participants. These data provide evidence for the premise that early acquisition of this single motor skill promotes the development of a childs fitness, body image, and participation in sport.

Symptoms of stress and depression effect percentage of body fat and insulin resistance in healthy youth: LOOK longitudinal study

Objective: This study examined the longitudinal and cross-sectional effects of both psychosocial stress and depressive symptoms on insulin resistance and percentage body fat in a cohort of healthy Australian children, following them from childhood into adolescence. Method: Participants were 791 healthy, initially Grade 2 children (7–8 years; 394 girls), selected from the general community. Psychosocial stress was assessed using the Children’s Stress Questionnaire, while depressive symptoms were assessed using the Children’s Depression Inventory. Fasting blood samples for serum insulin and plasma glucose were collected to calculate the homeostasis model assessment—insulin resistance (HOMA-IR). Other measurements were height, weight, percentage body fat (dual energy x-ray absorptiometry), physical activity (pedometers), and pubertal maturation (Tanner score). Results: Boys who reported more symptoms of depression had higher insulin resistance, irrespective of adiposity (p = .016); and longitudinally, we found a trend for boys who developed more depressive symptoms to develop higher insulin resistance (p = .073). These findings did not extend to girls. Furthermore, boys and girls with higher depressive symptoms had a higher percentage of body fat (p = .011 and .020, respectively); and longitudinally, boys whose depressive symptoms increased became fatter (p = .046). Conclusion: Our data provide evidence that early symptoms of depression increase insulin resistance, independent of adiposity. Our evidence that early symptoms of depression may lead to overweight, and obesity provides further reason to suggest that early attention to children with depression, even in preclinical stages, may reduce risk of chronic disease in later life.

Do self-reported stress and depressive symptoms effect endothelial function in healthy youth? The LOOK longitudinal study

Background and aims Endothelial dysfunction is thought to be an early indicator of risk for cardiovascular disease and has been associated with both stress and depression in adults and adolescents. Less is known of these relationships in younger populations, where the origins of CVD is thought to manifest. This study examined the effects of questionnaire derived psychosocial stress and depressive symptoms on endothelial function among children, following them through to adolescence. Method Participants were 203 grade 2 children (111 girls; M age = 7.6 ± 0.3 years) from the LOOK longitudinal study, who were followed through to adolescence (16 years). Self-reported psychosocial stress and depression were assessed using the validated Children’s Stress Questionnaire and a modified and validated version of the Children’s Depression Inventory respectively; endothelial function was assessed using EndoPAT 2000 system at follow-up only; and adjustments were made for fitness, pubertal development and socioeconomic status. Results Although all relationships occurred in the hypothesised direction, no cross-sectional or prospective evidence of early symptoms of psychological stress or depression being associated with endothelial dysfunction was found among our asymptomatic cohort of adolescents (all p > .05). Conclusions In contrast to previous findings in adolescents, our data provided little evidence of any relationship between current or previous psychosocial stress or depression and endothelial function in 16-year-old boys and girls. However, our data need to be interpreted alongside the potential limitations in the sensitivity associated with self-report methods for detecting psychological distress of children.

Impact of cultural background on fundamental movement skill and its correlates

ABSTRACT Children’s fundamental movement skill levels (FMS) predict moderate-to-vigorous physical activity (MVPA). Asian children have been reported as less active than English-Europeans, possibly due to poorer skills. This study compared the FMS of children from Culturally and Linguistically Diverse (CALD) backgrounds and examined FMS correlates. A total of 261 children (122 males) aged 9-to-11 years were divided based on language spoken at home: English-European (n = 105) and Asian (n = 156). Height, mass, FMS (Test of Gross Motor Development-2), MVPA (accelerometer) and cardio-respiratory fitness (20m multistage shuttle run) were directly measured. Sex, age, language and perceived sport competence (CY-PSPP) were self-reported. Independent sample t-tests assessed age, BMI, FMS and perception by CALD group. Linear mixed models examined FMS correlates. Asian-speaking children had lower object control skill (35.5 v 37.2; CI [0.17, 3.18]; p < 0.03) compared to English-European- children, but no between-group differences in locomotor skills were observed. Fitness, physical activity and sport competence perception were positively associated with object control, yet adjusting for these variables (and age and BMI) did not remove the CALD effect (B = −2.02, SE = 0.69, p = 0.004). Cultural factors may affect object control competence in Asian-Australian children.