Early physical activity provides sustained bone health benefits later in childhood

Impact of a multi-component implementation strategy to increase outdoor free play opportunities in early childhood education and care (ECEC) services: the get outside get active (GOGA) randomised controlled trial

BACKGROUND

Increased outdoor free play is associated with health and developmental benefits for preschool-aged children. It is therefore recommended that early childhood education and care (ECEC) services provide increased time for outdoor free play. This study seeks to understand the impact of a multi-component implementation strategy (Get Outside Get Active) on ECEC service provision of opportunities for outdoor free play.

METHODS

This was a parallel-group randomised controlled trial involving 84 ECEC services located in one region of New South Wales, Australia. Forty-one services were randomised to a 6-month multi-component implementation strategy or to a usual care group (n = 43). To increase total scheduled outdoor free play time, services were supported to modify their routines to increase provision of outdoor free play and/or indoor-outdoor free play opportunities (whereby children are allowed to move freely between indoor and outdoor spaces). The primary trial outcome, mean minutes per day of outdoor free play opportunities provided in ECEC services, was measured at baseline, 6-months (primary endpoint), and 18-months. Secondary outcomes were mean minutes of indoor-outdoor free play only and proportion implementing indoor-outdoor free play for the full day. The quality of the movement environment was assessed using direct observations in 30 ECECs at 6 months only.

RESULTS

At 6 months, the intervention group showed a significant increase in mean daily minutes of outdoor free play (61.3 min; 95% CI 2.5 to 120.01; p = 0.041) and indoor-outdoor free play (59.1 min; 95% CI 9.1 to 109.1; p = 0.021) relative to the control group. However, no significant between-group differences were observed at 18 months. The proportion implementing a full-day indoor-outdoor program (OR 1.97; 95% CI 0.81 to 4.78; p = 0.196) and the quality of movement environments did not differ between groups at 6 months.

CONCLUSIONS

The implementation strategy significantly increased outdoor free play opportunities in ECEC services post-intervention, though the between group effects were not sustained at 18 months. Future research should focus on ensuring the long-term impact of implementation strategies and understanding the factors driving changes in control group behaviour.

TRIAL REGISTRATION

This trial was prospectively registered with the Australian New Zealand Clinical Trials Registry (ACTRN12621000987864).

Playing sport as a central-line carrier: a survey to collect the European pediatric intestinal failure centers' view

BACKGROUND

The administration of home parenteral nutrition improves quality of life for patients with intestinal failure, thus fostering their will to actively participate to social activities. Nevertheless, sports participation can be risky for patients with a central venous catheter (CVC). Despite literature thoroughly proving the positive impact of sports on motor-psychosocial development, no consistent evidence assessing its role on central-line complications is available. This study aimed to report the European centers' approach to children with intestinal failure on home parenteral nutrition and interested in playing sports, further assessing complications and how to prevent them.

MATERIALS AND METHODS

A questionnaire focusing on children with intestinal failure regarding physical activity was circulated to 20 centers. Questions assessed the centers' policy for CVC management, the sports-related recommendations for patients on home parenteral nutrition and complication rates.

RESULTS

Sixteen (80%) centers filled in the questionnaire. Twelve centers reported not to have a standardized formal protocol for catheter care during sports. All centers encouraged patients to perform mild/moderate exercise, whereas high-contact sports were allowed by one center only. Specific dressings were suggested to protect the vascular access device, especially for water sports. Only one sports-related complication (rupture) was reported.

CONCLUSION

This survey emphasizes that sports should not be restricted in patients with intestinal failure and represents a blueprint for sports-related recommendations for these patients. Prospective studies assessing complication rates are advisable to ensure an improved access to sports for these patients.

The Cross-Sectional and Longitudinal Associations Between Adherence to 24-Hour Movement Behavior Guidelines and Bone Health in Young Children

BACKGROUND

Adherence to the World Health Organization's 24-hour movement behavior (24-HMB) guidelines is associated with various health outcomes. However, its relationship with bone mineral density (BMD) in young children has not been investigated. This study aimed to examine the cross-sectional and longitudinal associations between adherence to the 24-HMB guidelines and BMD in young children.

METHODS

A total of 120 children aged 3-5 years were recruited from three kindergartens in Changsha, Hunan, China. Physical activity (PA) was objectively measured using ActiGraph wGT3X-BT accelerometers, and BMD was assessed using the Sunlight Omnisense 7000P ultrasound device. Screen time (ST) and sleep duration (SD) were reported by parents. Logistic regression was used to analyze the associations between guideline adherence and BMD.

RESULTS

Only 5.5% of the participants met all three guidelines for PA, ST, and SD, while 16.5% did not meet any. In the cross-sectional analysis, young children who met both ST and SD guidelines (OR = 0.29, 95% CI: 0.09, 0.95) had a lower risk of insufficient BMD compared to those who met none. In the one-year cohort follow-up, young children who met the PA guideline at baseline (OR = 0.22, 95% CI: 0.07, 0.71), as well as those who met both the PA and ST guidelines (OR = 0.18, 95% CI: 0.04, 0.83) or all three (OR = 0.13, 95% CI: 0.03, 0.69), had a lower risk of insufficient BMD at one year.

CONCLUSIONS

Adherence to the 24-HMB guidelines may promote bone health in young children. Future research should prioritize achievable goals, such as limiting ST and ensuring adequate SD, while gradually increasing MVPA to optimize bone development.

Commemorating the monkey bars, catalyst of debate at the intersection of human evolutionary biology and public health

Play is an essential part of childhood, and growing attention has focused on the potential health benefits of 'risky' or 'thrill-seeking' play. Such play behavior is readily observed on any playground, where it can sometimes lead to injuries--most often from fall impacts--that require medical attention. Monkey bars account for ~7% of childhood arm fractures in the USA, an alarming statistic that raises difficult questions over its costs and benefits. Many authors view monkey bars as a public health hazard, but it is plausible that our childhood impulse toward thrill-seeking play is a result of selective pressures throughout our primate evolutionary history. Indeed, emerging evidence suggests that the developmental benefits of thrill-seeking play extend into adulthood, outweighing the occasional costs of injury. Disparate and consequential, these dueling perspectives have fueled debate among health professionals and policymakers, but with little attention to the work of biological anthropologists. Here we call attention to the hominin fossil record and play behaviors of non-human primates, providing a novel perspective that bolsters arguments for the adaptive significance of thrill-seeking play. The moment for such a review is timely, for it commemorates the centennial anniversaries of two playground icons: the jungle gym and monkey bars.

Per- and polyfluoroalkyl substances and bone mineral content in early adolescence: Modification by diet and physical activity

BACKGROUND

Per- and polyfluoroalkyl substance (PFAS) exposures may negatively impact bone mineral accrual, but little is known about potential mitigators of this relation. We assessed whether associations of PFAS and their mixture with bone mineral content (BMC) in adolescence were modified by diet and physical activity.

METHODS

We included 197 adolescents enrolled in a prospective pregnancy and birth cohort in Cincinnati, Ohio (2003-2006). At age 12 years, we collected serum for PFAS measurements and used dual-energy x-ray absorptiometry to measure BMC. We calculated dietary calcium intake and Health Eating Index (HEI) scores from repeated 24-h dietary recalls, physical activity scores using the Physical Activity Questionnaire for Older Children (PAQ-C), and average moderate to vigorous physical activity (MVPA) based on accelerometry. We estimated covariate-adjusted differences in BMC z-scores per interquartile range (IQR) increase of individual PFAS concentrations using linear regression and per simultaneous IQR increase in all four PFAS using g-computation. We evaluated effect measure modification (EMM) using interaction terms between each modifier and PFAS.

RESULTS

Higher serum perfluorooctanoic acid, perfluorooctanesulfonic acid, and perfluorononanoic acid concentrations and the PFAS mixture were associated with lower BMC z-scores. An IQR increase in all PFAS was associated with a 0.27 (-0.54, 0.01) lower distal radius BMC z-score. Associations with lower BMC were generally stronger among adolescents classified as < median for calcium intake, HEI scores, or MVPA compared to those ≥ median. The difference in distal radius BMC z-score per IQR increase in all PFAS was -0.38 (-0.72, -0.04) for those with

CONCLUSION

Healthy, calcium-rich diets and higher intensity physical activity may mitigate the adverse impact of PFAS on adolescent bone health.

Collapse

Key Words

• Adolescent health
• Bone mineral content
• Calcium
• Diet
• Perfluoroalkyl substances
• Physical activity

Collapse

MESH Headings

• Humans
• Female
• Fluorocarbons/blood
• Male
• Bone Density/drug effects
• Child
• Adolescent
• Diet
• Environmental Pollutants/blood
• Prospective Studies
• Ohio
• Alkanesulfonic Acids/blood
• Exercise
• Motor Activity/drug effects

Collapse

Grants

• R01 ES030078 NIEHS NIH HHS
• R01 ES033252 NIEHS NIH HHS
• R01 ES027224 NIEHS NIH HHS
• L40 ES032257 NIEHS NIH HHS
• P01 ES011261 NIEHS NIH HHS
• R01 ES032836 NIEHS NIH HHS
• R01 ES028277 NIEHS NIH HHS
• T32 ES007141 NIEHS NIH HHS
• R01 ES025214 NIEHS NIH HHS
• R01 ES020349 NIEHS NIH HHS

Collapse

Affiliation(s)

Jessie P Buckley Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
Junyi Zhou Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, USA
Katherine M Marquess Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, USA
Bruce P Lanphear Faculty of Health Sciences, Simon Fraser University, Vancouver, Canada
Kim M Cecil Department of Radiology, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, USA; Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, USA
Aimin Chen Department of Biostatistics, Epidemiology and Informatics, University of Pennsylvania Perelman School of Medicine, Philadelphia, USA
Clara G Sears Christina Lee Brown Envirome Institute, Department of Medicine, Division of Environmental Medicine, University of Louisville, KY, USA
Yingying Xu Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, USA
Kimberly Yolton Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, USA
Heidi J Kalkwarf Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, USA
Joseph M Braun Department of Epidemiology, Brown University, Providence, USA
Jordan R Kuiper Department of Environmental and Occupational Health, The George Washington University Milken Institute School of Public Health, Washington, D.C., USA

Collapse

Collaborators Collapse

Physical activity interventions among youth living in rural and remote areas: A systematic review

OBJECTIVES

Physical activity (PA) interventions have potential to improve health and social outcomes among youth. The aim of this study was to collate the evidence on the effectiveness of PA and sports-based interventions among youth living in rural and remote areas.

METHODS

We searched five databases and grey literature (HealthInfoNet). Search terms included PA, rural status, adolescents, and outcome measures. Studies were included if published in English, recruited 10- to 18-year olds, and were based in rural or remote communities (Modified Monash Model [MMM] area classification range of MMM 3-7). Quasi-experimental and pre-experimental and post-experimental PA interventions were included. Two authors evaluated the articles independently following the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines, and relevant data were extracted. International Prospective Register of Systematic Reviews (PROSPERO) (CRD42020199001).

RESULTS

Of the 11802 studies identified, 6 were included in the review. Most studies were excluded for not meeting MMM 3-7 criteria. Four of the included studies had sports-related interventions, and 2 had walking-based interventions. Outcomes included self-efficacy, mental health, and academic performance. One study reported a positive effect of PA on self-efficacy (β = 0.26, p=0.018, odds ratio = 1.43 [95% confidence interval: 1.07-1.92]).

CONCLUSION

Few community-based PA interventions have been evaluated in rural areas. There is a need for future evaluations in rural areas and include PA as an outcome measure.

IMPLICATIONS FOR PUBLIC HEALTH

The findings highlight the need for measurement of PA outcomes in PA interventions in rural and remote areas. The findings also highlight the need for research to utilise a standardised measure of rurality.

Cross-sectional and longitudinal associations between the 24-hour movement behaviours, including muscle and bone strengthening activity, with bone and lean mass from childhood to adolescence

BACKGROUND

This study aimed to assess whether moderate-to-vigorous physical activity (MVPA), sport and exercise as a proxy measure of muscle and bone strengthening activity, sedentary behaviour, and sleep were associated with total-body-less-head (TBLH) bone mineral content (BMC) and TBLH lean mass cross-sectionally and longitudinally from age 6 to 9 years and age 9 to 11 years to age 15 to 17 years.

METHODS

We used longitudinal data from a population sample of Finnish children from the Physical Activity and Nutrition in Children study (age 6 to 9 years: n = 478, 229 females; age 9 to 11 years: n = 384, 197 females; age 15 to 17 years: n = 222, 103 females). Linear regression analysed the cross-sectional and longitudinal associations between accelerometer-assessed MVPA, sedentary time and sleep, and questionnaire-assessed sport and exercise participation and screen time with dual-energy X-ray absorptiometry-assessed TBLH BMC and lean mass.

RESULTS

In females, MVPA at age 6 to 9 years was positively associated with TBLH BMC at age 15 to 17 years (β = 0.008, p = 0.010). Sport and exercise at age 9 to 11 years was positively associated with TBLH BMC (β = 0.020, p = 0.002) and lean mass (β = 0.343, p = 0.040) at age 15 to 17 years. MVPA at age 9 to 11 years was positively associated with TBLH lean mass (β = 0.272, p = 0.004) at age 15 to 17 years. In males, sleep at age 6 to 9 years was positively associated with TBLH lean mass (β = 0.382, p = 0.003) at age 15 to 17 years. Sport and exercise at age 9 to 11 years was positively associated with TBLH BMC (β = 0.027, p = 0.012) and lean mass (β = 0.721, p < 0.001) at age 15 to 17 years.

CONCLUSIONS

Promoting engagement in the 24-hour movement behaviours in childhood, particularly sport and exercise to strengthen muscle and bone, is important in supporting bone and lean mass development in adolescence.

TRIAL REGISTRATION

NCT01803776; first trial registration date: 04/03/2013.

Effects of the Type of Exercise Training on Bone Health Parameters in Adolescent Girls: A Systematic Review

Interventional studies offer strong evidence for exercise's osteogenic impact on bone particularly during growth. With rising osteoporosis rates in older women, enhancing bone strength early in life is crucial. Thus, investigating the osteogenic effects of different types of physical activities in young females is crucial. Despite varied findings, only two systematic reviews tried to explore this topic without examining how different types of exercise may affect bone health in adolescent girls. The first aim of this systematic review was to assess the impact of exercise training on bone health parameters in adolescent girls, and the second aim was to investigate whether the type of exercise training can modulate this effect. A systematic literature search was conducted using common electronic databases from inception - January 2023. Seven studies (355 participants) were eligible for inclusion in this systematic review. Two studies dealt with resistance training, 3 studies applied plyometric training, 1 study used team sports, and 1 study used dancing. Results indicate that plyometric training increases lumbar spine bone mass in adolescent girls. Well-designed randomized controlled trials with a proper training period (> 12 weeks) are needed to advocate a specific type of training which has the highest osteogenic effect.

Musculoskeletal health in children and adolescents

The purpose of this narrative review was to investigate the key determinants of musculoskeletal health in childhood and adolescence, with particular attention to the role of physical activity. First, we examined the importance of bone modeling and remodeling in maintaining the bone health and the integrity and mechanical characteristic of the skeleton. In addition, we reported the evidence on an appropriate calcium and vitamin D intake, as well as local load variation in achieving proper peak bone mass. Proteomic and transcriptomic studies identified the skeletal muscle "secretoma", consisting of several myokines involved in endocrine and paracrine functions. Among these, we explored the role of irisin, a myokine involved in the muscle-bone crosstalk, and in the regulation of metabolic pathways. It is known that physical activity during growing positively impacts on skeleton and can protect by bone loss in adulthood. However, there are still concerns about the optimal interval duration and exercise intensity, particularly at the pubertal growth spurt which represents a window of opportunity to increase skeletal strength. We reported data from clinical trials performed in the last 5 years analyzing the impact of the type and timing of physical activity during childhood on skeletal development. Finally, we reported recent data on the significance of physical activity in some rare diseases.

Impact of Seated Movement Incorporation on Middle School Classroom Physical Activity Levels and Academic Engagement

Purpose: Physical inactivity is linked with several chronic diseases and poor academic outcomes. This study aimed to examine the effect an under-the-desk band would have on middle school students' physical activity level, and academic engagement. Methods: Two local middle school classrooms (n = 42, M = 20, F = 22) participated in the study, which was conducted over 14 weeks. Physical activity was measured with accelerometry, and academic engagement was assessed using momentary time sampling. Enrolled participants were provided an accelerometer to wear upon entering the classroom. The baseline period lasted for 36 days. During the intervention period, which lasted for the next 30 days, an under-the-desk band was provided to students to freely fidget at their desks. After the study, 13 participants (M = 5, F = 8) in Class A were included in final physical activity analysis, and the 6 participants (M = 3, F = 3) in Class B were included in the academic engagement analysis. Results: Class A had significant increases in percentage of sedentary time (MD = -12.91%, ES = .88) in addition to significant decreases in the percentage of light (MD = 8.82%, ES = .67), moderate (MD = 3.08%, ES = .84), and vigorous (MD = -.04%, ES = .63) physical activity time during the intervention period compared to the baseline period. No significant or meaningful changes occurred in academic engagement with the use of the under-the-desk band. Conclusions: This study high- lights the importance of finding appropriate methods to increase physical activity for adolescents.

Age and school-segment difference in daily sedentary behavior and physical activity among student (9-23 years): a cross-sectional accelerometer-based survey

This study is cross-sectional in nature and aims to investigate and track sedentary behavior (SB) and physical activity among student (aged 9-23 years) for seven consecutive days using an accelerometer. It also intends to analyze the current status of the daily activities of students using age and school-segment differences. The study recruits a total of 384 students [age: 14.41 ± 3.52 years; body mass index (BMI): 19.66 ± 3.67] from four schools out of which 180 (46.88%) were male. The study uses the means and standard deviations for statistical analysis and independent sample t-tests to determine gender differences. Analysis of covariance is used to determine whether or not daily SB and physical activity were statistically significant students according to gender and school segment followed by LSD post hoc tests for multiple comparisons. The results demonstrate that students were less physically active [moderate- to vigorous-intensity physical activity (MVPA):60.4 ± 23.48 min/day] and more sedentary (598.47 ± 162.63 min/day). The sedentary time of the students displays an inverted U-trend, and their participation in MVPA exhibits a W-shape. After controlling for BMI, the results of ANCOVA point to a significant school-segment effect (p < 0.001) for SB (F = 83, η_p² = 0.4) and physical activity (low-intensity physical activity: F = 108.61, η_p² = 0.47; MPA: F = 401.65, η_p² = 0.76; high-intensity physical activity: F = 88.43, η_p² = 0.42; MVPA: F = 118.42, η_p² = 0.49). Based on the behavioral characteristics of students across school segments, this study concluded that interventions targeting students' physical activity and physical health should be school segment specific. The results of the study provide a basis for future analysis of factors influencing students' physical activity behaviors across school segments and for proposing targeted intervention strategies for the future.

The Influence of Accelerometer Epoch Length on Associations of Physical Activity Intensity and Volume with Bone Outcomes

Two accelerometer metrics (intensity-gradient and average-acceleration) can be used to determine the relative contributions of physical activity (PA) volume and intensity for health, but it is unknown whether epoch length influences the associations detected. This is important when considering bone health, as bone is particularly responsive to high intensity PA, which may be underestimated by longer epochs. This study aimed to assess the associations between average-acceleration, a proxy measure of PA volume, and intensity-gradient, reflective of PA intensity distribution, from PA data from 1-s to 60-s epochs at age 17 to 23 years with bone outcomes at age 23 years. This is a secondary analysis of 220 participants (124 females) from the Iowa Bone Development Study, a longitudinal study of bone health from childhood to early adulthood. Accelerometer-assessed PA data, captured at age 17 to 23 years, were summarised over 1-s, 5-s, 15-s, 30-s, and 60-s epochs, to generate average-acceleration and intensity-gradient from each epoch length, averaged across ages. Regression analysed associations between mutually adjusted average-acceleration and intensity-gradient with dual-energy X-ray absorptiometry assessed total-body-less-head (TBLH) bone mineral content (BMC), spine areal bone mineral density (aBMD), hip aBMD, and femoral neck cross-sectional area and section modulus at age 23 years. Intensity-gradient was positively associated with TBLH BMC in females, with spine aBMD in males, and with hip aBMD and geometry in both sexes, when a 1 to 5-s epoch was used. Average-acceleration was positively associated with TBLH BMC, spine aBMD and hip aBMD in males, generally when the adjustment for intensity-gradient was from > 1-s epochs. Intensity and volume were important for bone outcomes in both sexes and males, respectively. A 1 to 5-s epoch length was most appropriate to assess the mutually adjusted associations of intensity-gradient and average-acceleration with bone outcomes in young adults.

Peak Loads Associated With High-Impact Physical Activities in Children

Physical activities involving impact loading are important for improving bone strength and mineral density in children. There is little research quantifying impact loads associated with various high-impact activities.

PURPOSE

Examine the magnitude of peak ground reaction forces (pGRF) across different jumping activities in children.

METHODS

Eight children between 8 and 12 years (9.63 [1.49] y; 1.42 [0.08] m; 33.69 [4.81] kg), performed 5 trials of a broad jump, countermovement jump, jumping jack, leap jump, and drop jump on a force plate. The pGRF were determined during the landing phase of each activity and expressed in units of body weight (BW). A repeated-measures analysis of variance was employed to assess differences in pGRF across activities.

RESULTS

Drop jump exhibited the greatest pGRF (3.09 [0.46] BW) in comparison with the vertical jumping jack (2.56 [0.21] BW; P < .001) and countermovement jump (2.45 [0.22] BW; P = .001), as well as the horizontal broad jump (2.25 [0.2] BW; P = .003), and leap jump (2.01 [0.1] BW; P = .002).

CONCLUSION

Peak loads between 2 and 3.1 BW were exhibited across each jump activity, which is moderate compared with magnitudes in most jump interventions seeking to improve bone health. All conditions except drop jump exhibited loading <3 BW, suggesting these activities may not produce sufficient loads to improve bone outcomes.

A randomised controlled trial of an implementation strategy delivered at scale to increase outdoor free play opportunities in early childhood education and care (ECEC) services: a study protocol for the get outside get active (GOGA) trial

BACKGROUND

Increased outdoor play time in young children is associated with many health and developmental benefits. This study aims to evaluate the impact of a multi-strategy implementation strategy delivered at scale, to increase opportunities for outdoor free play in Early Childhood Education and Care (ECEC) services.

METHODS

The study will employ a parallel-group randomised controlled trial design. One hundred ECEC services in the Hunter New England region of New South Wales, Australia, will be recruited and randomised to receive either a 6-month implementation strategy or usual care. The trial will seek to increase the implementation of an indoor-outdoor routine (whereby children are allowed to move freely between indoor and outdoor spaces during periods of free play), to increase their opportunity to engage in outdoor free play. Development of the strategy was informed by the Behaviour Change Wheel to address determinants identified in the Theoretical Domains Framework. ECEC services allocated to the control group will receive 'usual' implementation support delivered as part of state-wide obesity prevention programs. The primary trial outcome is the mean minutes/day (calculated across 5 consecutive days) of outdoor free play opportunities provided in ECEC services measured at baseline, 6-months (primary end point) and 18-months post baseline. Analyses will be performed using an intention-to-treat approach with ECEC services as the unit of analysis, using a linear mixed effects regression model to assess between-group differences. A sensitivity analysis will be undertaken, adjusting for service characteristics that appear imbalanced between groups at baseline, and a subgroup analysis examining potential intervention effect among services with the lowest baseline outdoor free play opportunities.

DISCUSSION

Identifying effective strategies to support the implementation of indoor-outdoor routines in the ECEC setting at scale is essential to improve child population health.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry ( ACTRN12621000987864 ). Prospectively registered 27th July 2021, ANZCTR - Registration.

A lifespan approach to osteoarthritis prevention

Prevention is an attractive solution for the staggering and increasingly unmanageable burden of osteoarthritis. Despite this, the field of osteoarthritis prevention is relatively immature. To date, most of what is known about preventing osteoarthritis and risk factors for osteoarthritis is relative to the disease (underlying biology and pathophysiology) of osteoarthritis, with few studies considering risk factors for osteoarthritis illness, the force driving the personal, financial and societal burden. In this narrative review we will discuss what is known about osteoarthritis prevention, propose actionable prevention strategies related to obesity and joint injury which have emerged as important modifiable risk factors, identify where evidence is lacking, and give insight into what might be possible in terms of prevention by focussing on a lifespan approach to the illness of osteoarthritis, as opposed to a structural disease of the elderly. By targeting a non-specialist audience including scientists, clinicians, students, industry employees and others that are interested in osteoarthritis but who do not necessarily focus on osteoarthritis, the goal is to generate discourse and motivate inquiry which propel the field of osteoarthritis prevention into the mainstream.

Physical activity and fat-free mass during growth and in later life

BACKGROUND

Physical activity may be a way to increase and maintain fat-free mass (FFM) in later life, similar to the prevention of fractures by increasing peak bone mass.

OBJECTIVES

A study is presented of the association between FFM and physical activity in relation to age.

METHODS

In a cross-sectional study, FFM was analyzed in relation to physical activity in a large participant group as compiled in the International Atomic Energy Agency Doubly Labeled Water database. The database included 2000 participants, age 3-96 y, with measurements of total energy expenditure (TEE) and resting energy expenditure (REE) to allow calculation of physical activity level (PAL = TEE/REE), and calculation of FFM from isotope dilution.

RESULTS

PAL was a main determinant of body composition at all ages. Models with age, fat mass (FM), and PAL explained 76% and 85% of the variation in FFM in females and males < 18 y old, and 32% and 47% of the variation in FFM in females and males ≥ 18 y old, respectively. In participants < 18 y old, mean FM-adjusted FFM was 1.7 kg (95% CI: 0.1, 3.2 kg) and 3.4 kg (95% CI: 1.0, 5.6 kg) higher in a very active participant with PAL = 2.0 than in a sedentary participant with PAL = 1.5, for females and males, respectively. At age 18 y, height and FM-adjusted FFM was 3.6 kg (95% CI: 2.8, 4.4 kg) and 4.4 kg (95% CI: 3.2, 5.7 kg) higher, and at age 80 y 0.7 kg (95% CI: -0.2, 1.7 kg) and 1.0 kg (95% CI: -0.1, 2.1 kg) higher, in a participant with PAL = 2.0 than in a participant with PAL = 1.5, for females and males, respectively.

CONCLUSIONS

If these associations are causal, they suggest physical activity is a major determinant of body composition as reflected in peak FFM, and that a physically active lifestyle can only partly protect against loss of FFM in aging adults.

Development and Content Validity of the Physical Activity Questionnaire-Young Children (PAQ-YC) to Assess Physical Activity in Children between 5 and 7 Years

Childhood is a critical period in the development and consolidation of healthy habits, such as the practice of physical activity (PA). It is essential to have valid instruments to measure PA from an early age. The aim of this study was to design and evaluate the content validity of the Physical Activity Questionnaire-Young Children (PAQ-YC) to measure the PA level in children aged 5-7 years. The first version of the questionnaire was tested by a 2-round Delphi study. It was established as a consensus criterion that the relative interquartile range (RIR) and/or the coefficient of variation (CV) were ≤20%. The most significant discrepancies in the Delphi survey (n = 11-13) were observed for items about hours of Physical Education or similar activities at school (item 7: RIR = 20, CV = 38.73) and for items about participation in Physical Education (item 8: RIR = 25, CV = 15.45). The cognitive interviews (n = 5) confirmed the version agreed by the experts. The results show that the PAQ-YC presents adequate content validity in terms of relevance, comprehensiveness and comprehensibility.

Strategies for Teachers to Promote Physical Activity in Early Childhood Education Settings-A Scoping Review

Recent evidence has emphasized the importance of the early childhood years for developing lifelong physical activity patterns. As such, evidence-informed programs that create opportunities for young children to engage in physical activity are needed and education settings present an important context. This review aimed to identify strategies that are implemented by teachers to promote physical activity in early childhood education and care settings. This is a scoping review that followed the framework proposed by the Joanna Briggs Institute. Searches were conducted using the databases of PubMed, SCOPUS, PsycINFO, SPORT Discus, ERIC and Web of Science for publications up to September 2020. From a total of 8974 articles, 19 were deemed eligible. Ten types of strategies, performed by teachers with the intention to improve physical activity-related primary outcomes, were identified. Physical activity promotion by teachers in early childhood settings is recommended to take a multi-strategy approach, in conjunction with professional development training opportunities and continuous follow-up support for teachers. Future work is warranted to fill the evidence gap in other regions (e.g., Asia, Africa and South America) and strengthen the evidence base to establish best practice standards.

Association of objectively measured physical activity and bone health in children and adolescents: a systematic review and narrative synthesis

The influence of day-to-day physical activity on bone in adolescence has not been well characterized. Forty articles were identified that assessed the relationship between accelerometry-derived physical activity and bone outcomes in adolescents. Physical activity was positively associated with bone strength in peri-pubertal males, with less consistent evidence in females. Physical activity (PA) is recommended to optimize bone development in childhood and adolescence; however, the influence of day-to-day PA on bone development is not well defined. The aim of this review was to describe the current evidence for objectively measured PA on bone outcomes in healthy children and adolescents. MEDLINE, Embase, Cochrane Library, Scopus, Web of Science, CINAHL, PsycInfo, and ClinicalTrials.gov were searched for relevant articles up to April 2020. Studies assessing the relationship between accelerometry-derived PA and bone outcomes in adolescents (6-18 years old) were included. Two reviewers independently screened studies for eligibility, extracted data, and rated study quality. Forty articles met inclusion criteria (25 cross-sectional, 15 longitudinal). There was significant heterogeneity in accelerometry methodology and bone outcomes measured. Studies in males indicated a significant, positive relationship between moderate to vigorous PA (MVPA) and bone outcomes at the hip and femur, particularly during the peri-pubertal years. The results for MVPA and bone outcomes in females were mixed. There was a paucity of longitudinal studies using pQCT and a lack of data regarding how light PA and/or impact activity influences bone outcomes. The current evidence suggests that objectively measured MVPA is positively associated with bone outcomes in children and adolescents, especially in males. However, inconsistencies in methodology make it difficult to determine the amount and type of PA that leads to favorable bone outcomes. Given that the majority of research has been conducted in Caucasian adolescents, further research is needed in minority populations.

Physical activity, sedentary time, and longitudinal bone strength in adolescent girls

The association between baseline physical activity and sedentary time with 2-year longitudinal bone strength was evaluated. The effect of physical activity on bone depended on maturity status. Sedentary time did not negatively impact bone outcomes, regardless of maturity. Maturity should be considered when developing exercise interventions to improve bone outcomes.

INTRODUCTION

Physical activity during adolescence is important to obtain peak bone mass; however, adolescents are increasingly sedentary, potentially increasing risk for osteoporosis later in life. The aim of this study was to assess the association of physical activity and sedentary time with 2-year longitudinal bone outcomes in adolescent females (69% Hispanic/31% non-Hispanic).

METHODS

Bone strength was assessed at the 66% tibia, 20% femur, and 66% radius of 9- to 12-year-old girls (n = 131) using peripheral quantitative computed tomography at baseline and 2-year follow-up. Physical activity and sedentary time were assessed via accelerometry. Linear regression analyses were used to assess whether baseline vigorous physical activity (VPA), moderate physical activity (MPA), light physical activity (LPA), or sedentary time predict longitudinal bone outcomes, adjusting for relevant confounders.

RESULTS

Significant interactions were found between maturity offset and physical activity. In weight-bearing bones, significant interactions were primarily identified between VPA and maturity offset. Interactions indicated that VPA was associated with favorable bone outcomes at the tibia and femur in girls further past the age of PHV. However, this favorable effect was not observed in girls closer to the age of PHV. At the radius, interactions were primarily observed between LPA and maturity offset. Again, LPA was more beneficial for girls further past the age of PHV. Sedentary time did not significantly influence bone outcomes.

CONCLUSION

The effects of physical activity on bone may be dependent on maturity. Therefore, physical activity interventions, with attention to maturity status, may be required to optimize bone strength in girls.

Impact of physical activity, anthropometric, body composition, and dietary factors on bone stiffness in German university students

BACKGROUND

Bone density in the young-adult life is associated with risk for osteoporosis in later life. Next to genetic factors, lifestyle seems to play an important role for bone health. Aim of the study was to clarify the relationship between various lifestyle factors and bone parameters in university students.

METHODS

In 233 women and 52 men (age: 22.7±3.1 vs. 24.0±3.2 years; BMI: 22.2±2.9 vs. 24.2±3.1 kg∙m^-2) the following parameters were assessed: calcaneal Stiffness Index ([SI]; quantitative ultrasound), body composition (bioelectrical impedance analysis), actual and past physical activity level ([PAL]; standardized questionnaire), and food/nutrient intake (3-day dietary record). Sex differences (Mann-Whitney-U-tests), relationships between SI and lifestyle factors (Spearman's rank correlation), and the influence of the factors on the variance of SI (multiple linear regression) were tested (α=0.05).

RESULTS

6.9% of the women and 5.8% of the men were classified as osteopenic (-2.5< T score <-1). Significant correlations between SI and BMI, absolute fat mass and fat-free mass, actual PAL, and physical activity during adolescence were found in women (r=0.18-0.24, all P<0.05), but not in men. Food/nutrient parameters did not significantly correlate with bone outcomes (P>0.05). In multiple regression analysis physical activity during adolescence, actual PAL, and BMI explained 8% of the variance of SI (P<0.0001): SI=32.2+3.5∙physical activity during adolescence [1: very low, 2: low, 3: medium, 4: high, 5: very high] +28.5∙PAL+0.8∙BMI [kg∙m^-2].

CONCLUSIONS

Parameters of physical activity seem to be more important for bone health than nutrition factors. Therefore, high levels of physical activity during childhood, adolescence, and early-adult life are highly recommended to improve bone parameters.

How Physical Activity across the Lifespan Can Reduce the Impact of Bone Ageing: A Literature Review

Bone remodeling is a lifelong process, due to the balanced activity of the osteoblasts (OBs), the bone-forming cells, and osteoclasts (OCs), the bone-resorbing cells. This equilibrium is mainly regulated by the WNT-ß-cathenin pathway and the RANK-RANKL/OPG system, respectively. Bone ageing is a process which normally occurs during life due to the imbalance between bone formation and bone resorption, potentially leading to osteoporosis. Bone loss associated with bone ageing is determined by oxidative stress, the result of the increasing production of reactive oxygen species (ROS). The promotion of physical exercise during growth increases the chances of accruing bone and delaying the onset of osteoporosis. Several studies demonstrate that physical exercise is associated with higher bone mineral density and lower fracture incidence, and the resulting bone mineral gain is maintained with ageing, despite a reduction of physical activity in adulthood. The benefits of exercise are widely recognized, thus physical activity is considered the best non-pharmacologic treatment for pathologies such as osteoporosis, obesity, diabetes and cardiovascular disease. We reviewed the physiological mechanisms which control bone remodeling, the effects of physical activity on bone health, and studies on the impact of exercise in reducing bone ageing.

Quantifying Physical Activity in Young Children Using a Three-Dimensional Camera

The purpose of this study was to determine the feasibility and validity of using three-dimensional (3D) video data and computer vision to estimate physical activity intensities in young children. Families with children (2–5-years-old) were invited to participate in semi-structured 20-minute play sessions that included a range of indoor play activities. During the play session, children’s physical activity (PA) was recorded using a 3D camera. PA video data were analyzed via direct observation, and 3D PA video data were processed and converted into triaxial PA accelerations using computer vision. PA video data from children (n = 10) were analyzed using direct observation as the ground truth, and the Receiver Operating Characteristic Area Under the Curve (AUC) was calculated in order to determine the classification accuracy of a Classification and Regression Tree (CART) algorithm for estimating PA intensity from video data. A CART algorithm accurately estimated the proportion of time that children spent sedentary (AUC = 0.89) in light PA (AUC = 0.87) and moderate-vigorous PA (AUC = 0.92) during the play session, and there were no significant differences (p > 0.05) between the directly observed and CART-determined proportions of time spent in each activity intensity. A computer vision algorithm and 3D camera can be used to estimate the proportion of time that children spend in all activity intensities indoors.

Infants' and toddlers' physical activity and sedentary time as measured by accelerometry: a systematic review and meta-analysis

BACKGROUND

Early experiences in physical activity (PA) are important to shape healthy movement behaviours long-term; as such, it is critical that PA is promoted from infancy, and that detrimental behaviours (e.g., prolonged sedentary time [ST]) are minimized. The purpose of this systematic review and meta-analysis was to examine infants' and toddlers' movement behaviours across daytime hours.

METHODS

Seven online databases were searched for terms related to infants (< 12 months), toddlers (12-35.9 months), PA, ST, and accelerometry. Two independent reviewers examined 4873 articles for peer-reviewed original research, published in English, that assessed infants' (counts/min) and/or toddlers' PA or ST (min/day) using accelerometry across daytime hours. Infants' mean PA level (counts/min) was averaged across studies, and ranges were produced. Estimates of toddlers' movement behaviours were aggregated meta-analytically to produce average daily rates, and accelerometer placement, cut-point validity, device type, and epoch length were tested as a moderating variables.

RESULTS

Twenty-four studies from 16 countries (published 2011-2019), representing 3699 participants, were included in the systematic review. Five studies reported on infants' PA, which ranged from 78.2 to 2580.5 cpm. Across 20 studies, toddlers' total PA, light PA, moderate-to vigorous-intensity PA, and ST ranged from 72.9 to 636.5, 48.5 to 582.4, 6.5 to 89.9, and 172.7 to 545.0 min/day, respectively. After taking into account accelerometer placement, cut-point validity, device type, and epoch length, we found that toddlers engaged in 246.19 min/day (SE = 28.50; 95% CI: 190.34, 302.04) of total PA, 194.10 min/day (SE = 28.76; 95% CI: 137.73, 250.47) of light PA, and 60.16 min/day (SE = 5.88; 95% CI: 48.64, 71.69) of moderate-to vigorous-intensity PA. Toddlers engaged in 337.04 min/day (SE = 32.67; 95% CI: 273.01, 401.07) of ST.

CONCLUSIONS

With limited studies conducted in infants (n = 5), PA estimates are inconclusive and largely heterogeneous. Overall, toddlers tend to exceed the total PA recommendation of 180 min/day; however, very little of this time is spent at higher movement intensities. Even with high PA rates, toddlers still engage in substantial ST. More consistent and valid measurement protocols are needed to improve comparability across studies.

Neuromuscular Diseases and Bone

Neuromuscular diseases (NMDs) are inherited or acquired conditions affecting skeletal muscles, motor nerves, or neuromuscular junctions. Most of them are characterized by a progressive damage of muscle fibers with reduced muscle strength, disability, and poor health-related quality of life of affected patients. In this scenario, skeletal health is usually compromised as a consequence of modified bone-muscle cross-talk including biomechanical and bio-humoral issues, resulting in increased risk of bone fragility and fractures. In addition, NMD patients frequently face nutritional issues, including malnutrition due to feeding disorders and swallowing problems that might affect bone health. Moreover, in these patients, low levels of physical activity or immobility are common and might lead to overweight or obesity that can also interfere with bone strength features. Also, vitamin D deficiency could play a critical role both in the pathogenesis and in the clinical scenario of many NMDs, suggesting that its correction could be useful in maintaining or enhancing bone health, especially in the early phases of NMDs. Last but not least, specific disease-modifying drugs, available for some NMDs, are frequently burdened with adverse effects on bone tissue. For example, glucocorticoid therapy, standard of care for many muscular dystrophies, prolongs long-term survival in treated patients; nevertheless, high dose and/or chronic use of these drugs are a common cause of secondary osteoporosis. This review addresses the current state of knowledge about the factors that play a role in determining bone alterations reported in NMDs, how these factors can modify the biological pathways underlying bone health, and which are the available interventions to manage bone involvement in patients affected by NMDs. Considering the complexity of care of these patients, an interdisciplinary and multimodal management strategy based on both pharmacological and non-pharmacological interventions is recommended, particularly targeting musculoskeletal issues that are closely related to functional independence as well as social implications.

A Cluster Randomised Controlled Trial of an Intervention to Increase Physical Activity of Preschool-Aged Children Attending Early Childhood Education and Care: Study Protocol for the 'Everybody Energise' Trial

The use of ‘Energisers,’ short bouts of moderate-to-vigorous physical activity (MVPA), have been shown to significantly increase children’s physical activity within the school setting but not within Early Childhood Education and Care (ECEC) centres. The aim of this study is to assess the efficacy of an intervention involving the provision of educator-led daily Energisers to increase the time children spend in MVPA while attending ECEC. Fourteen ECEC centres in the Hunter region of New South Wales, Australia, will be randomised to either an intervention or control group. The intervention group will be supported by the research team to implement three brief (5-min) educator-led Energisers each day for children aged three to six years between the hours of 9:00 a.m. to 3.00 p.m. Control ECEC centres will continue to provide ‘normal practice’ to children. The primary trial outcome is child minutes of MVPA whilst in ECEC, assessed objectively via accelerometery over three days. Outcome assessment will occur at baseline and 6 months post-baseline. Linear mixed models under an intention-to-treat framework will be used to compare differences between groups in MVPA at follow-up. This will be the first cluster randomised controlled trial to test the efficacy of Energisers in isolation on increasing the time children spend in MVPA.

The effects of supplementing maternal and infant diets with lipid-based nutrient supplements on physical activity and sedentary behaviour at preschool age in Ghana

Evidence on whether nutritional supplementation affects physical activity (PA) during early childhood is limited. We examined the long-term effects of lipid-based nutrient supplements (LNS) on total PA, moderate-to-vigorous PA (MVPA) and sedentary behaviour (SB) of children at 4-6 years using an accelerometer for 1 week. Their mothers were enrolled in the International Lipid-based Nutrient Supplement-DYAD randomised controlled trial in Ghana, assigned to daily LNS or multiple micronutrients (MMN) during pregnancy through 6 months postpartum or Fe and folic acid (IFA) during pregnancy and placebo for 6 months postpartum. From 6 to 18 months, children in the LNS group received LNS; the other two groups received no supplements. Analysis was done with intention to treat comparing two groups: LNS v. non-LNS (MMN+ IFA). Of the sub-sample of 375 children fitted with accelerometers, 353 provided sufficient data. Median vector magnitude (VM) count was 1374 (interquartile range (IQR) 309), and percentages of time in MVPA and SB were 4·8 (IQR 2) and 31 (IQR 8) %, respectively. The LNS group (n 129) had lower VM (difference in mean -73 (95 % CI -20, -126), P = 0·007) and spent more time in SB (LNS v. non-LNS: 32·3 v. 30·5 %, P = 0·020) than the non-LNS group (n 224) but did not differ in MVPA (4·4 v. 4·7 %, P = 0·198). Contrary to expectations, provision of LNS in early life slightly reduced the total PA and increased the time in SB but did not affect time in MVPA. Given reduced social-emotional difficulties in the LNS group previously reported, including hyperactivity, one possible explanation is less restless movement in the LNS group.

Comparison of cardiorespiratory fitness between preschool children with normal and excess body adipose ~ An observational study

Objective

Overweight and obesity in preschoolers might develop into childhood and even adulthood obesity. Overweight and obesity have been shown to be negatively related with cardiorespiratory fitness (CRF) in children and adults but few studies did among preschoolers. We aimed to evaluate whether excess body adipose is negatively associated with CRF in both the submaximal and maximal effort of preschool children in exercise testing and to examine if there is difference to achieve maximal effort during exercise testing between preschoolers with normal and excess body adipose.

Methods

Data of 106 preschoolers aged 4–6 that received symptom-limited treadmill exercise testing was analyzed. Anthropometry was measured by vector bioelectrical impedance analysis. Excess body adipose was defined as (1) ‘overweight’ and ‘obesity’ by body mass index (BMI), (2) fat mass index (FMI) greater than the sex- and age-specific 75th percentile of whole subjects, and (3) fat-free mass index (FFMI) smaller than the sex- and age-specific 25th percentile. CRF was indicated by metabolic equivalent (MET) at anaerobic threshold (AT MET), peak MET, oxygen uptake efficiency slope (OUES) calculated by the 50% (OUES-50) and the entire (OUES-100) duration of the exercise testing.

Results

Preschoolers with excess body adipose by three different definitions (BMI, FMI, and FFMI) all had poorer ability to perform maximal effort (p = 0.004, 0.043, and 0.007, respectively). Preschoolers with excess body adipose by BMI and FFMI classifications had lower OUES-50 (p = 0.018, and 0.001, respectively), and lower OUES-100 (p = 0.004, and 0.001, respectively) than peers with normal body adipose during exercise testing while those with excess body adipose by FMI classification showed no significant differences from peers with normal body adipose in both OUES-50 and OUES-100.

Conclusions

Preschoolers with excess body adipose had lower CRF significantly during treadmill exercise testing. Weight control and health promotion should start as early as possible.

Bone Health and Its Relationship with Impact Loading and the Continuity of Physical Activity throughout School Periods

Bone is influenced by physical activity (PA) throughout life, but childhood and adolescence provide a key opportunity to maximize peak bone mass. Thus, it is important to identify the relationship between PA practiced in childhood and young adulthood to design a promotion plan for bone health. The purpose of this study was to analyze the relationship between different impact-loading PAs (and their continuity throughout school periods from childhood to young adulthood) and bone stiffness index (SI). In this cross-sectional study, which was conducted on 145 university students aged 18-21 years, bone measurements were measured by quantitative ultrasonometry (QUS), and PA information was recalled using a self-administered questionnaire. Associations between the SI and the impact of PA performed during secondary school (p = 0.027), high school (p = 0.002), and university (p = 0.016) periods were observed. The continuity of PA over a longer period of time was related to a higher SI (p = 0.007). Those who practiced PA throughout all school periods had a higher SI than those who practiced during primary school only (p = 0.038) or through primary and secondary schools (p = 0.009). These results suggest that impact-loading PA practiced during different school periods is related to higher values of the SI. Therefore, continuous PA from an early age may be an important contributing factor to achieving and maintaining adequate bone health.

China National Assessment of Education Quality - Physical Education & Health (CNAEQ-PEH) 2015: An Introduction

PURPOSE

To summarize the framework and development procedure of the China National Assessment of Education Quality - Physical Education & Health in 2015 (CNAEQ-PEH 2015), an authoritative and evidence-based national surveillance protocol developed by the Ministry of Education of the People's Republic of China for Grade 4 and Grade 8 students.

METHODS

The framework of CNAEQ-PEH 2015 included a test battery of physical fitness and health outcomes and self-reported questionnaires regarding facilitators and barriers to physical fitness and health in school settings and family status, completed by students, teachers, and principals. A qualified, standardized, and responsible work procedure was generated to provide insights into the quality of data collection and supervision of large-scale school-based physical fitness testing implementation. Measure development, stratified unequal probability sampling, and implementation were included in the working procedure.

RESULTS

In the first circle of the CNAEQ-PEH conducted on June 18, 2015, 111,173 Grade 4 students from 4,015 elementary schools and 72,243 Grade 8 students from 2,461 middle schools, along with their principals (n = 6,447) and physical education (PE) teachers (n = 11,418), were sampled by probability proportionate to size (PPS) across 323 counties in China. Results provided detailed information regarding students' physical fitness outcomes, learning, lifestyle, and educational environment.

CONCLUSIONS

CNAEQ-PEH 2015 is a large-scale assessment of physical fitness and health outcomes. It helps provide opportunities to understand the physical fitness and health status of Chinese Grade 4 and 8 students and to study the correlations of physical fitness and health, as well as their relationship with education-related indicators and academic performance.

Physical Activity and Health in Children Younger than 6 Years: A Systematic Review

PURPOSE

Physical activity is known to provide important health benefits in school-age youth. However, until recently, few studies have examined associations between physical activity and health in young children. The purpose of this study was to conduct a systematic review of the relationship between physical activity and selected health outcomes in children younger than 6 yr.

METHODS

A systematic search identified randomized controlled trials and prospective cohort studies examining the associations between physical activity and adiposity/weight status, bone health, cardiometabolic health, and cognition in children younger than 6 yr.

RESULTS

Twenty-seven studies met inclusion criteria and served as the basis for this systematic review. For weight status/adiposity, 12 of 15 studies found negative associations between physical activity and one or more measures of the outcome. For bone health, 10 articles based on four studies were identified, and nine studies showed stronger bone in more active children. For cardiometabolic health, three studies were identified and findings were limited and inconsistent. For cognition, two systematic reviews were identified and findings were limited. For all four health outcomes, evidence of dose-response relationships and effect modification by demographic factors was very limited.

CONCLUSIONS

There is strong evidence indicating that higher amounts of physical activity are associated with better indicators of bone health and with reduced risk for excessive increases in weight and adiposity in children 3 to 6 yr. Evidence was too limited to support conclusions regarding the effects of physical activity on cardiometabolic health and cognition.

Is vigorous-intensity physical activity required for improving bone mass in adolescence? Findings from a Brazilian birth cohort

The association between moderate and vigorous physical activity throughout adolescence and areal bone density (aBMD) at 18 years of age was evaluated. Vigorous-intensity physical activity at 11, 15, and 18 years was associated with aBMD in early adulthood, especially in boys. Cross-sectional analyses showed a positive association between moderate physical activity and aBMD.

INTRODUCTION

To evaluate independent associations of moderate and vigorous physical activity (MPA, VPA) across adolescence with areal bone mineral density (aBMD).

METHODS

Physical activity (PA) was assessed at 11, 15, and 18 years of age by self-report and at 18 years by accelerometry in the 1993 Pelotas Birth Cohort Study. Time spent in MPA and VPA was determined using metabolic equivalents and specific cutoffs based on raw acceleration. Lumbar spine and femoral neck aBMD were measured by DXA at 18 years. Statistical analyses evaluated the association of MPA and VPA with aBMD, after adjusting for skin color, asset index, current height and age at menarche, and peak strain score (based on ground reaction forces of PA).

RESULTS

Lumbar spine and femoral neck aBMD were available for 3947 (49.9% of boys) and 3960 (49.6% of boys) individuals, respectively. Time spent in MPA at 11 and 15 years was not associated with aBMD. VPA at all time points was positively related to both lumbar spine and femoral neck aBMD in boys. Results were consistent for objectively measured VPA. Girls who achieved 75+ minutes/week of VPA in at least two follow-ups showed higher aBMD at 18 years of age. Boys who reached 75+ minutes/week of VPA at all follow-ups had on average 0.117 g/cm² (95% CI: 0.090; 0.144) higher femoral neck aBMD than those who never achieved this threshold.

CONCLUSIONS

Self-reported VPA but not MPA throughout adolescence was associated with aBMD. Recommendation for PA in young people should consider the importance of VPA.

Does Perception of Motor Competence Mediate Associations between Motor Competence and Physical Activity in Early Years Children?

OBJECTIVES

To examine if the relationship between physical activity (PA) and actual motor competence (MC) in British early years children is mediated by their perceived MC.

DESIGN

Cross-sectional convenience observational study.

METHODOLOGY

MC was assessed with six locomotor skills (LC) and six object-control skills (OC) via the Test of Gross Motor Development-2. PA was measured via a wrist-worn triaxial accelerometer and PA grouped as daily total PA (TPA) and moderate-to-vigorous PA (MVPA). Perceived MC was assessed using the Pictorial Scale of Perceived Competence and Acceptance for Young Children. A total of 38 children (63% male; 37% female) aged between 3 and 6 years (5.41 ± 0.69) completed all assessments. Mediating impacts of perceived MC on the relationships between PA and MC were explored via backwards mediation regressions.

RESULTS

There were no mediating impacts of perceived MC on the relationship between PA and actual MC.

CONCLUSIONS

The relationship between actual MC and PA is not mediated by perceived MC in a small sample of British early years childhood.

Don't take down the monkey bars: Rapid systematic review of playground-related injuries

OBJECTIVE

To synthesize the available evidence on playground-related injuries and to determine the prevalence of these injuries in pediatric populations.

DATA SOURCES

A rapid systematic review was conducted using PubMed, EMBASE, and the Cochrane Library, as well as the gray literature.

STUDY SELECTION

The search was limited to studies published between 2012 and 2016 and identified a total of 858 articles, of which 22 met our inclusion criteria: original quantitative studies published in peer-reviewed journals in the past 5 years, concerning unintentional injuries in playgrounds in children aged 0 to 18 years.

SYNTHESIS

Information was collected on study and injury characteristics, and the proportion of pediatric injuries related to playground activity was determined. Studies were performed in various countries and most were retrospective cohort studies. The prevalence of playground-related injury ranged from 2% to 34% (median 10%). Studies varied in the types of injuries investigated, including head injuries, genitourinary injuries, ocular and dental trauma, and various types of fractures. Most injuries were low severity.

CONCLUSION

Although playgrounds are a common location where pediatric injuries occur, these injuries are relatively low in frequency and severity.

Relationships between Motor Competence, Physical Activity, and Obesity in British Preschool Aged Children

BACKGROUND

This cross-sectional study aimed to examine associations between motor competence, physical activity, and obesity in British children aged three to five years.

METHOD

Motor competence (MC) was assessed using the Test of Gross Motor Development-2. Physical activity (PA) was assessed using triaxial wrist-worn accelerometers. Children were assessed on compliance to current PA recommendations of ≥180 min of total PA (TPA) and ≥60 min of moderate-to-vigorous PA (MVPA) for health benefits. Associations were explored with Pearson's product moments and weight-status, and sex-differences were explored with independent t-tests and chi-squared analysis.

RESULTS

A total of 166 children (55% males; 4.28 ± 0.74 years) completed MC and PA assessments. Associations were found between PA and MC (TPA and overall MC, TPA and object-control MC (OC), MVPA and overall MC, and MVPA and OC). This study suggests that good motor competence is an important correlate of children meeting physical activity guidelines for health.

Impact of scheduling multiple outdoor free-play periods in childcare on child moderate-to-vigorous physical activity: a cluster randomised trial

Background

Increasing the frequency of periods of outdoor free-play in childcare may represent an opportunity to increase child physical activity. This study aimed to assess the efficacy of scheduling multiple periods of outdoor free-play in increasing the time children spend in moderate-to-vigorous physical activity (MVPA) while attending childcare.

Methods

The study employed a cluster randomised controlled trial design involving children aged 3 to 6 years, attending ten childcare services in the Hunter New England region of New South Wales, Australia. Five services were randomised to receive the intervention and five to a control condition. The intervention involved services scheduling three separate periods of outdoor free-play from 9 am to 3 pm per day, each at least 15 min in duration, with the total equivalent to their usual daily duration of outdoor play period. Control services implemented the usual single continuous period of outdoor free-play over this time. The primary outcome, children’s moderate-to-vigorous physical activity (MVPA) while in care per day, was measured over 5 days via accelerometers at baseline and at 3 months post baseline. Secondary outcomes included percentage of time spent in MVPA while in care per day, total physical activity while in care per day and documented child injury, a hypothesised potential unintended adverse event. Childcare services and data collectors were not blind to the experimental group allocation.

Results

Parents of 439 (71.6%) children attending participating childcare services consented for their child to participate in the trial. Of these, 316 (72.0%) children provided valid accelerometer data at both time points. Relative to children in control services, mean daily minutes of MVPA in care was significantly greater at follow-up among children attending intervention services (adjusted difference between groups 5.21 min, 95% CI 0.59–9.83 p = 0.03). Percentage of time spent in MVPA in care per day was also greater at follow-up among children in intervention services relative to control services (adjusted difference between groups 1.57, 95% CI 0.64–2.49 p < 0.001). Total physical activity while in care per day, assessed via counts per minute approached but did not reach significance (adjusted difference between groups 14.25, 95% CI 2.26–30.76 p = 0.09). There were no differences between groups in child injury nor subgroup interactions for the primary trial outcome by child age, sex, or baseline MVPA levels.

Conclusion

Scheduling multiple periods of outdoor free-play significantly increased the time children spent in MVPA while in attendance at childcare. This simple ecological intervention could be considered for broader dissemination as a strategy to increase child physical activity at a population level.

Trial registration

This trial was prospectively registered with the Australian New Zealand Clinical Trials Registry (ANZCTR) (ACTRN1261000347460). Prospectively registered 17th March 2016.

Electronic supplementary material

The online version of this article (10.1186/s12966-018-0665-5) contains supplementary material, which is available to authorized users.

Diversity of activity participation determines bone mineral content in the lower limbs of pre-pubertal children with developmental coordination disorder

This study examined the relationships between activity participation and bone mineralization in children with developmental coordination disorder. Limited participation in physical, recreational, social, and skill-based and self-improvement activities contributed to lower bone mineral content. For improved bone health, these children should participate in a variety of activities, not only physical activities.

INTRODUCTION

Limited activity participation in children with developmental coordination disorder (DCD) may have a negative impact on bone mineral accrual. The objectives of this study were to compare bone mineralization and activity participation patterns of pre-pubertal children with DCD and those with typical development, and to determine the association between activity participation patterns and bone mineralization in children with DCD.

METHODS

Fifty-two children with DCD (mean age = 7.51 years) and 61 children with typical development (mean age = 7.22 years) participated in the study. Appendicular and total body (less head) bone mineral content (BMC) and bone mineral density (BMD) were evaluated by a whole-body dual-energy X-ray absorptiometry scan. Activity participation patterns were assessed using the Children's Assessment of Participation and Enjoyment (CAPE) questionnaire.

RESULTS

Children with DCD had lower appendicular and total body BMCs and BMDs than children with typical development overall (p < 0.05). They also had lower CAPE total activity and physical activity diversity scores (p < 0.05). After accounting for the effects of age, sex, height, lean mass, and fat mass, the total activity diversity score remained independently associated with leg BMC in children with DCD, explaining 5.1% of the variance (p = 0.030). However, the physical activity diversity score was no longer associated with leg BMC (p = 0.090).

CONCLUSIONS

Diversity of activity participation and bone mineralization were lower in pre-pubertal children with DCD. Decreased total activity participation diversity was a contributing factor to lower BMC in the legs of children with DCD.

Structural Strength Benefits Observed at the Hip of Premenarcheal Gymnasts Are Maintained Into Young Adulthood 10 Years After Retirement From the Sport

PURPOSE

Premenarcheal female gymnasts have been consistently found to have greater bone mass and structural advantages. However, little is known about whether these structural advantages are maintained after the loading stimulus is removed. Therefore, the purpose of this study was to investigate the structural properties at the hip after long-term retirement from gymnastics.

METHODS

Structural properties were derived from dual-energy X-ray absorptiometry scans using the hip structural analysis program for the same 24 gymnasts and 21 nongymnasts both in adolescence (8-15 y) and adulthood (22-30 y). Structural measures were obtained at the narrow neck, intertrochanter, and femoral shaft and included cross-sectional area, section modulus, and buckling ratio. Multivariate analysis of covariance was used to assess differences between groups in bone measures while controlling for size, age, maturity, and physical activity.

RESULTS

Gymnasts were found to have structural advantages at the narrow neck in adolescence (16% greater cross-sectional area, 17% greater section modulus, and 25% lower buckling ratio) and 14 years later (13% greater cross-sectional area and 26% lower buckling ratio). Benefits were also found at the intertrochanter and femoral shaft sites in adolescence and adulthood.

CONCLUSION

Ten years after retirement from gymnastics, former gymnasts' maintained significantly better hip bone structure than females who did not participate in gymnastics during growth.

Effects of the Healthy Start randomized intervention trial on physical activity among normal weight preschool children predisposed to overweight and obesity

BACKGROUND

There is limited evidence to support the effectiveness of primary interventions aiming to prevent excess weight gain among young children. Evaluating behavioral changes, such as physical activity (PA), may add to future development of efficient interventions. The objective was to evaluate the effect on PA outcomes of the 15 month Healthy Start intervention that focused on changing diet, PA, sleep and stress management among normal weight but obesity-prone preschool children. Children were defined as obesity-prone if they had a birth weight > 4,000 g, mothers with a pre-pregnancy body mass index of > 28 kg/m2, or mothers with ≤ 10 years of schooling.

METHOD

From a baseline study population of 635 normal weight 2-6 year old preschool children from the greater Copenhagen area, parents of 307 children had given information on PA at both the baseline and follow-up examinations. PA was obtained from a 7 days recording in the Children's Physical Activity Questionnaire. Time used for sport activities were combined with outdoor playing time to achieve a proxy of total PA level of moderate to vigorous intensity.

RESULTS

Linear regression analyses revealed that at follow-up the intervention group spent more time on sports and outdoor activities combined per week than the control group (ITT analyses: intervention: 400 min/week; 95% confidence interval (CI): 341, 459 versus control: 321 min/week; 95% CI: 277, 366; p = 0.02), although no significant intervention effects were seen for each of the subcategories, e.g. sports participation, outdoor activities, screen time, or commuting frequency.

CONCLUSION

Our results suggest that the overall time spent on sports and outdoor activities combined was increased at follow-up among normal weight obesity-prone children, as a result of the Healthy Start intervention.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01583335.

A shared biomechanical environment for bone and posture development in children

BACKGROUND CONTEXT

In each specific habitual standing posture, gravitational forces determine the mechanical setting provided to skeletal structures. Bone quality and resistance to physical stress is highly determined by habitual mechanical stimulation. However, the relationship between bone properties and sagittal posture has never been studied in children.

PURPOSE

This study aimed to investigate the association between bone physical properties and sagittal standing postural patterns in 7-year-old children. We also analyzed the relationship between fat or fat-free mass and postural patterns.

STUDY DESIGN

Cross-sectional evaluation.

PATIENT SAMPLE

This study was performed in a sample of 1,138 girls and 1,260 boys at 7 years of age participating in the Generation XXI study, a population-based cohort of children followed since birth (2005-2006) and recruited in Porto, Portugal.

OUTCOME MEASURES

Sagittal standing posture was measured through photographs of the sagittal right view of children in the standing position. Three angles were considered to quantify the magnitude of major curves of the spine and an overall balance measure (trunk, lumbar, and sway angles). Postural patterns were identified using latent profile analysis in Mplus.

METHODS

Weight and height were measured. Total body less head fat or fat-free mass and bone properties were estimated from whole-body dual-energy X-ray absorptiometry scans. The associations of fat or fat-free mass and bone physical properties with postural patterns were jointly estimated in latent profile analysis using multinomial logistic regressions.

RESULTS

The identified patterns were labeled as Sway, Flat, and "Neutral to Hyperlordotic" (in girls), and "Sway to Neutral," Flat, and Hyperlordotic (in boys). In both genders, children in the Flat pattern showed the lowest body mass index, and children with a rounded posture presented the highest: mean differences varying from -0.86 kg/m² to 0.60 kg/m² in girls and from -0.70 kg/m² to 0.62 kg/m² in boys (vs. Sway or "Sway to Neutral"). Fat and fat-free mass were inversely associated with a Flat pattern and positively associated with a rounded posture: odds ratio (OR) of 0.23 per standard deviation (SD) fat and 0.70 per SD fat-free mass for the Flat pattern, and 1.85 (fat) and 1.43 (fat-free) for the Hyperlordotic pattern in boys, with similar findings in girls. The same direction of relationships was observed between bone physical properties and postural patterns. A positive association between bone (especially bone mineral density) and a rounded posture was robust to adjustment for age, height, and body composition (girls: OR=1.79, p=.006 fat-adjusted, OR=2.00, p=.014 fat-free mass adjusted; boys: OR=2.02, p=.002 fat-adjusted, OR=2.42, p<.001 fat-free mass adjusted).

CONCLUSIONS

In this population-based pediatric setting, there was an inverse association between bone physical properties and a Flat posture. Bone and posture were more strongly positively linked in a rounded posture. Our results support that both bone properties and posture mature in a shared and interrelated mechanical environment, probably modulated by pattern-specific anthropometrics and body composition.

Role of Inactivity in Chronic Diseases: Evolutionary Insight and Pathophysiological Mechanisms

This review proposes that physical inactivity could be considered a behavior selected by evolution for resting, and also selected to be reinforcing in life-threatening situations in which exercise would be dangerous. Underlying the notion are human twin studies and animal selective breeding studies, both of which provide indirect evidence for the existence of genes for physical inactivity. Approximately 86% of the 325 million in the United States (U.S.) population achieve less than the U.S. Government and World Health Organization guidelines for daily physical activity for health. Although underappreciated, physical inactivity is an actual contributing cause to at least 35 unhealthy conditions, including the majority of the 10 leading causes of death in the U.S. First, we introduce nine physical inactivity-related themes. Next, characteristics and models of physical inactivity are presented. Following next are individual examples of phenotypes, organ systems, and diseases that are impacted by physical inactivity, including behavior, central nervous system, cardiorespiratory fitness, metabolism, adipose tissue, skeletal muscle, bone, immunity, digestion, and cancer. Importantly, physical inactivity, itself, often plays an independent role as a direct cause of speeding the losses of cardiovascular and strength fitness, shortening of healthspan, and lowering of the age for the onset of the first chronic disease, which in turn decreases quality of life, increases health care costs, and accelerates mortality risk.

Application of the Rosetta Stone to understand how much MVPA preschoolers accumulate: A systematic review

OBJECTIVES

This study illustrates the utility of the Rosetta Stone equations for comparing estimates of preschool-age children's moderate-to-vigorous physical activity (MVPA) across studies utilizing different cutpoints.

DESIGN

Systematic review.

METHODS

A search of online databases was conducted to identify studies that reported daily minutes of MVPA in preschoolers using the cutpoints from which Rosetta Stone equations have been developed. Mean MVPA minday^-1 from each study and the transformed estimate using the Rosetta Stone equations were compared across 7 sets of cutpoints. The weighted mean was used to calculate absolute differences between the MVPA estimates of studies using the same cutpoints (e.g all studies that have used Pate cutpoint), and from all of the remaining studies using different cutpoints (e.g., all remaining studies that have not used Pate cutpoint), before and after the Rosetta Stone transformation.

RESULTS

A total of 33 manuscripts met the eligibility criteria and reported MVPA for 12,178 preschoolers (50% girls). The mean MVPA for the total sample ranged from 21.1 (Puyau cutpoint) to 288.6 (Freedson cutpoints) minday^-1. The difference between studies using the same cutpoint and estimates from remaining studies using different cutpoints was 82.4 and 80.0minday^-1 for boys and girls, respectively. These differences were reduced to approximately 14minday^-1 for boys and girls, after Rosetta Stone transformations.

CONCLUSIONS

The Rosetta Stone equations substantially reduced the differences across studies that utilize different cutpoints and improved the ability to interpret findings across studies. Future equations should be developed for sedentary and total physical activity, as well as, comparisons across different devices and placements.

Process evaluation of a preschool physical activity intervention using web-based delivery

BACKGROUND AND PURPOSE

Preschool/childcare settings offer a practical target for physical activity interventions. Online learning programs have the potential for greater public health reach and impact. The SHAPES-Dissemination (SHAPES-D) project adapted the original SHAPES in-person intervention for online delivery to teachers. The purpose of this paper is to describe the implementation monitoring and process evaluation for the SHAPES-D project.

METHODS

Nine preschools with 26 classrooms participated. A total of 41 teachers were trained via online learning to implement the SHAPES-D program in their classrooms. The dose received, completeness, and fidelity of implementation were assessed through website metrics, teacher surveys and interviews, and classroom observations.

RESULTS

Dose received was adequate (73%). Observed completeness and physical activity enjoyment fidelity were high (100%), although moderate-to-vigorous physical activity fidelity and social environment fidelity were low (25% each). Overall implementation was high (91%).

DISCUSSION

Results indicate that the online method of delivery is viable for dissemination. The online delivery system provides an easy method of monitoring dose received. This may be the first structural intervention to monitor dose received through web metrics.

CONCLUSION

The adaptation of an in-person intervention to an online delivery system increases the potential for dissemination of a successful program to increase physical activity in preschool settings.

Systematic review of the relationships between objectively measured physical activity and health indicators in school-aged children and youth

Moderate-to-vigorous physical activity (MVPA) is essential for disease prevention and health promotion. Emerging evidence suggests other intensities of physical activity (PA), including light-intensity activity (LPA), may also be important, but there has been no rigorous evaluation of the evidence. The purpose of this systematic review was to examine the relationships between objectively measured PA (total and all intensities) and health indicators in school-aged children and youth. Online databases were searched for peer-reviewed studies that met the a priori inclusion criteria: population (apparently healthy, aged 5-17 years), intervention/exposure/comparator (volumes, durations, frequencies, intensities, and patterns of objectively measured PA), and outcome (body composition, cardiometabolic biomarkers, physical fitness, behavioural conduct/pro-social behaviour, cognition/academic achievement, quality of life/well-being, harms, bone health, motor skill development, psychological distress, self-esteem). Heterogeneity among studies precluded meta-analyses; narrative synthesis was conducted. A total of 162 studies were included (204 171 participants from 31 countries). Overall, total PA was favourably associated with physical, psychological/social, and cognitive health indicators. Relationships were more consistent and robust for higher (e.g., MVPA) versus lower (e.g., LPA) intensity PA. All patterns of activity (sporadic, bouts, continuous) provided benefit. LPA was favourably associated with cardiometabolic biomarkers; data were scarce for other outcomes. These findings continue to support the importance of at least 60 min/day of MVPA for disease prevention and health promotion in children and youth, but also highlight the potential benefits of LPA and total PA. All intensities of PA should be considered in future work aimed at better elucidating the health benefits of PA in children and youth.

Interventions to prevent and treat corticosteroid-induced osteoporosis and prevent osteoporotic fractures in Duchenne muscular dystrophy

BACKGROUND

Corticosteroid treatment is considered the 'gold standard' for Duchenne muscular dystrophy (DMD); however, it is also known to induce osteoporosis and thus increase the risk of vertebral fragility fractures. Good practice in the care of those with DMD requires prevention of these adverse effects. Treatments to increase bone mineral density include bisphosphonates and vitamin D and calcium supplements, and in adolescents with pubertal delay, testosterone. Bone health management is an important part of lifelong care for patients with DMD.

OBJECTIVES

To assess the effects of interventions to prevent or treat osteoporosis in children and adults with DMD taking long-term corticosteroids; to assess the effects of these interventions on the frequency of vertebral fragility fractures and long-bone fractures, and on quality of life; and to assess adverse events.

SEARCH METHODS

On 12 September 2016, we searched the Cochrane Neuromuscular Specialised Register, CENTRAL, MEDLINE, Embase, and CINAHL Plus to identify potentially eligible trials. We also searched the Web of Science ISI Proceedings (2001 to September 2016) and three clinical trials registries to identify unpublished studies and ongoing trials. We contacted correspondence authors of the included studies in the review to obtain information on unpublished studies or work in progress.

SELECTION CRITERIA

We considered for inclusion in the review randomised controlled trials (RCTs) and quasi-RCTs involving any bone health intervention for corticosteroid-induced osteoporosis and fragility fractures in children, adolescents, and adults with a confirmed diagnosis of DMD. The interventions might have included oral and intravenous bisphosphonates, vitamin D supplements, calcium supplements, dietary calcium, testosterone, and weight-bearing activity.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed reports and selected potential studies for inclusion, following standard Cochrane methodology. We contacted study authors to obtain further information for clarification on published work, unpublished studies, and work in progress.

MAIN RESULTS

We identified 18 potential studies, of which two, currently reported only as abstracts, met the inclusion criteria for this review. Too little information was available for us to present full results or adequately assess risk of bias. The participants were children aged five to 15 years with DMD, ambulant and non-ambulant. The interventions were risedronate versus no treatment in one trial (13 participants) and whole-body vibration versus a placebo device in the second (21 participants). Both studies reported improved bone mineral density with the active treatments, with no improvement in the control groups, but the abstracts did not compare treatment and control conditions. All children tolerated whole-body vibration treatment. No study provided information on adverse events. Two studies are ongoing: one investigating whole-body vibration, the other investigating zoledronic acid.

AUTHORS' CONCLUSIONS

We know of no high-quality evidence from RCTs to guide use of treatments to prevent or treat corticosteroid-induced osteoporosis and reduce the risk of fragility fractures in children and adults with DMD; only limited results from two trials reported in abstracts were available. We await formal trial reports. Findings from two ongoing relevant studies and two trials, for which only abstracts are available, will be important in future updates of this review.

Increasing physical activity among young children from disadvantaged communities: study protocol of a group randomised controlled effectiveness trial

BACKGROUND

Participation in regular physical activity (PA) during the early years helps children achieve healthy body weight and can substantially improve motor development, bone health, psychosocial health and cognitive development. Despite common assumptions that young children are naturally active, evidence shows that they are insufficiently active for health and developmental benefits. Exploring strategies to increase physical activity in young children is a public health and research priority.

METHODS

Jump Start is a multi-component, multi-setting PA and gross motor skill intervention for young children aged 3-5 years in disadvantaged areas of New South Wales, Australia. The intervention will be evaluated using a two-arm, parallel group, randomised cluster trial. The Jump Start protocol was based on Social Cognitive Theory and includes five components: a structured gross motor skill lesson (Jump In); unstructured outdoor PA and gross motor skill time (Jump Out); energy breaks (Jump Up); activities connecting movement to learning experiences (Jump Through); and a home-based family component to promote PA and gross motor skill (Jump Home). Early childhood education and care centres will be demographically matched and randomised to Jump Start (intervention) or usual practice (comparison) group. The intervention group receive Jump Start professional development, program resources, monthly newsletters and ongoing intervention support. Outcomes include change in total PA (accelerometers) within centre hours, gross motor skill development (Test of Gross Motor Development-2), weight status (body mass index), bone strength (Sunlight MiniOmni Ultrasound Bone Sonometer), self-regulation (Heads-Toes-Knees-Shoulders, executive function tasks, and proxy-report Temperament and Approaches to learning scales), and educator and parent self-efficacy. Extensive quantitative and qualitative process evaluation and a cost-effectiveness evaluation will be conducted.

DISCUSSION

The Jump Start intervention is a unique program to address low levels of PA and gross motor skill proficiency, and support healthy lifestyle behaviours among young children in disadvantaged communities. If shown to be efficacious, the Jump Start approach can be expected to have implications for early childhood education and care policies and practices, and ultimately a positive effect on the health and development across the life course.

TRIAL REGISTRATION

Australian and New Zealand Clinical Trials Registry No: ACTRN12614000597695 , first received: June 5, 2014.

A randomised controlled trial of multiple periods of outdoor free-play to increase moderate-to-vigorous physical activity among 3 to 6 year old children attending childcare: study protocol

BACKGROUND

The implementation of physical activity interventions in centre-based childcare services has been recommended to improve child health. This study aims to evaluate the efficacy of scheduling multiple periods of outdoor free play in increasing the time children spend in moderate-to-vigorous physical activity (MVPA) during childcare.

METHODS

The study will employ a between group cluster randomised controlled trial design. Fourteen childcare services in the Hunter New England region of New South Wales, Australia, who currently implement a single session of free outdoor play between their core operational hours of 9 am to 3 pm will be recruited into the trial. Childcare services will be randomised to an intervention or a no intervention control group. Childcare services in the intervention group will be supported by an early childhood education specialist to provide three periods of outdoor free play for children between the hours of 9 am to 3 pm. Each period of outdoor free play will be at least 15 min in duration but must equate to their total usual duration of outdoor play. Services in the control group will continue to implement a single period of outdoor play. The primary trial outcome is minutes of time children spend in MVPA whilst in care assessed objectively via accelerometer over 5 days. Outcome assessment will occur at baseline and 3 months post baseline. Generalised Linear Mixed Models (GLMM) under an intention to treat framework will be used to compare differences between groups in the primary trial outcome at follow-up. Sensitivity analysis will be conducted to test assumptions of missing data. Per protocol analysis will be performed using services that implemented the intervention as intended and subgroup analysis undertaken by gender and baseline physical activity levels of children.

DISCUSSION

The study tests a simple ecological intervention that has the potential to increase child physical activity in care.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry 12616000347460 . Prospectively registered 17th March 2016.

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.