Utility of accelerometers to measure physical activity in children attending an obesity treatment intervention

Integrating Heart Rate Monitoring Into a Camp for Children With Neuromotor Disorders: A Case Series

PURPOSE

This case series investigated the implementation fidelity, feasibility, and effectiveness of integrating continuous heart rate monitoring with visual feedback into an established, intensive physical therapy camp for children with neuromotor disorders.

SUMMARY OF KEY POINTS

The provision of continuous visual feedback through color-coded, individually calculated heart rate zones was a feasible and effective intervention, encouraging pediatric gait camp participants to exercise at intensities that produced aerobic and functional gains. The use of technology facilitated participation with peers, an outcome equally as important as their endurance and functional improvements.

CONCLUSIONS AND RECOMMENDATIONS FOR CLINICAL PRACTICE

Pediatric physical therapists play a crucial role in enhancing the well-being and physical fitness of children with disabilities. Encouraging regular exercise in a social environment fosters enjoyable, inclusive experiences while promoting overall health. It is important for clinicians in various pediatric rehabilitation settings to establish programs that offer such opportunities for children with neuromotor disorders.

acc: An R package to process, visualize, and analyze accelerometer data

Wearable activity monitors are now widely used in behavioral and epidemiological studies to measure physical activity in free-living conditions. Despite the widespread use in research, the development of software to explore the data collected from these devices has been limited. We present acc, a comprehensive, free, and open-source R package to provide a seamless environment for exploring accelerometer data (https://cran.r-project.org/web/packages/acc). In this article, we demonstrate the software for processing, visualizing, and analyzing accelerometer data using real and simulated datasets.

School Health Education Program in Pakistan (SHEPP): findings from a feasibility trial in pre-adolescent school children from a lower middle-income country

BACKGROUND

The school environment plays an essential role in promoting health education and physical activity for children and adolescents. We aim to assess the feasibility of threefold health education program in children and its potential efficacy on physical activity and diet and cardiometabolic risk factors including blood pressure, body mass index (BMI), and waist circumference.

METHODS

The SHEPP was a parallel group feasibility intervention trial conducted in two schools over 23 months. All children aged 9-11 years enrolled in the schools were included. The SHEPP intervention comprised of health education on healthy lifestyle and physical activity sessions for children, training of teachers, and awareness sessions for parents conducted over 10 months. One school received the intervention of SHEPP while the other school continued routine activity. The primary outcome was the feasibility of SHEPP in terms of recruitment, retention, and treatment fidelity. Secondary outcomes were physical activity levels, dietary intake (of fruits and vegetables), and cardiometabolic risk factors (blood pressure, BMI, and waist circumference (WC)).

RESULTS

A total of 1280 preadolescent children were assessed for eligibility and 1191 were found eligible. The overall recruitment n (%) was 982/1191(82.5%) with 505(51.4) from SHEPP intervention school and 477(48.6) in routine activity school. The overall retention rate n (%) at 10-month follow-up was 912/982(92.8), with 465/505(92) in SHEPP intervention school and 447/477(93.7) in routine activity school. In treatment fidelity, 132/144(92) %). Physical activity sessions and all (100%) health education sessions were conducted for each of the twelve classes. Mean (SD) Seven-day Physical activity increased by 134 (196) min in the SHEPP intervention school v 29.8(177) in the routine activity school (P value < 0.001) from baseline to follow-up. Overall, there was an increase in vegetable intake (> 3 serving /day) in SHEPP intervention school of 5.5 to 21.4% from baseline to follow-up compared to 7.5 to 14.9% in routine activity school. The mean change (SD) in systolic blood pressure was 1.3(12) mmHg, 2.2(19.0) mm Hg in in diastolic blood pressure, - 0.09(5.4) kg/m² in BMI and 6.2 cm in waist circumference in the intervention arm versus - 3.4(11.1) mm Hg in SBP, - 4.3(9.9) mm Hg in DBP, - 0.04((4.6) kg/m² in BMI, and 3.8 cm in WC in the control arm.

CONCLUSION

We found that intervention using SHEPP is feasible in schools and may help children to adopt a healthy lifestyle as they age by increasing physical activity. However, the potentially beneficial effect on diet, MI, and BP needs further exploration and a longer follow-up, more specifically at the juncture of teenage and adulthood.

TRIAL REGISTRATION

NCT03303287.

Insights into Non-Exercise Physical Activity on Control of Body Mass: A Review with Practical Recommendations

Non-exercise physical activity (NEPA), also called unstructured or informal physical activity, refers to those daily activities that require movement of the human body without planning or strict control of the physical effort made. Due to new technologies and motorized transportation devices, the general population has significantly decreased its NEPA. This increase in sedentary lifestyles, physical inactivity, and excessive energy intake is considered a risk factor for obesity, non-communicable diseases (NCDs), and all-cause mortality. Searching in PubMed/MEDLINE and Web of Science databases, a narrative review of NEPA was carried out to address its conceptualization, promotion strategies for the general population, and monitoring through wearable devices. It is strongly recommended that governmental entities, health practitioners, and the construction industry adhere to "The Global Action Plan on Physical Activity 2018-2030: More Active People for a Healthier World" and implement different salutogenic urban strategies. These strategies aim to generate environments that motivate increases in NEPA, such as cycling and walking transportation (between 5000-12,500 steps per day), and the progression to physical exercise. There is a wide variety of electronic devices for personal use, such as accelerometers, smartphone apps, or "smart clothes", that allow for the monitoring of NEPA, some with a wide range of analysis variables contributing to the estimation of total daily energy expenditure and the promotion of healthy habits. In general, the further promotion and monitoring of NEPA is required as part of a strategy to promote healthy habits sustainable over time for the prevention and control of obesity and NCDs.

A function-based approach to model the measurement error in wearable devices

Physical activity (PA) is an important risk factor for many health outcomes. Wearable-devices such as accelerometers are increasingly used in biomedical studies to understand the associations between PA and health outcomes. Statistical analyses involving accelerometer data are challenging due to the following three characteristics: (i) high-dimensionality, (ii) temporal dependence, and (iii) measurement error. To address these challenges we treat accelerometer-based measures of PA as a single function-valued covariate prone to measurement error. Specifically, in order to determine the relationship between PA and a health outcome of interest, we propose a regression model with a functional covariate that accounts for measurement error. Using regression calibration, we develop a two-step estimation method for the model parameters and establish their consistency. A test is also proposed to test the significance of the estimated model parameters. Simulation studies are conducted to compare the proposed methods with existing alternative approaches under varying scenarios. Finally, the developed methods are used to assess the relationship between PA intensity and BMI obtained from the National Health and Nutrition Examination Survey data.

Objectively Measured Physical Activity Is Lower in Individuals with Normal Weight Obesity in the United States

The role of physical activity in normal weight obesity (NWO), which is associated with increased cardiometabolic risk, is not clear. This study aimed to determine body composition phenotype-specific differences in objectively measured physical activity and sedentary time in adults in the United States. A total of 2055 adults with a body mass index (BMI) ≥ 18.5 m² were studied using 2003-2006 National Health and Nutrition Examination Surveys. Physical activity and percent body fat (BF%) were measured using accelerometer and dual-energy X-ray absorptiometry, respectively. A BF% > 23.1% and >33.3% for men and women, respectively, was considered excess. A BMI of 18.5-24.9 kg/m² with excess BF% was defined as NWO, while those with normal BF%, as normal weight lean (NWL). A BMI of ≥25 kg/m² with excess BF% was considered overweight/obesity (OB). Compared to NWL, moderate to vigorous physical activity was significantly lower by 8.3 min (95% confidence interval/CI = -15.20, -1.40) and 10.18 min (95% CI = -14.83, -5.54) per day in NWO and OB, respectively. Low-intensity physical activity was also significantly lower by 17.71 min (95% CI = -30.61, -4.81) per day in NWO compared to NWL. However, sedentary time was not different. Objectively measured physical activity is significantly lower in NWO compared to NWL, while sedentary time is not.

Relations between physical activity, sedentary time, and body fat from childhood to adolescence: Do they differ by sex?

BACKGROUND

Efforts to reveal the direction of influence between physical activity (PA), sedentary time (ST) and body fat in youth have produced inconsistent results, possibly due to a lack of adjustment for confounders and other factors. Sex-specific associations have rarely been studied.

METHODS

A sample from two Norwegian birth cohorts (n = 809) were followed biennially over five waves from the age of 6-14 years. Physical activity and ST were recorded by accelerometers, and body fat was assessed by bioelectrical impedance measurements.

RESULTS

By applying a dynamic panel model (DPM) that adjusts for all time-invariant confounding factors, it was found that among boys, increased fat mass index (FMI) at ages 8, 10 and 12 years predicted decreased PA two years later (8-10 years: B = -0.67, (95% CI: -1.1, -0.24); 10-12 years: B = -0.33, (95% CI: -0.61, -0.05); 12-14 years: B = -0.29, (95% CI: -0.52, -0.06)). Regarding the opposite direction of influence, more PA at age 12 forecasted reduced FMI at age 14 (B = -0.16, (95% CI: -0.24, -0.07)), whereas increased FMI predicted increased ST across all time points in boys only (6-8 years: B = 0.23, (95% CI:0.02.43); 8-10 years: B = 0.23, (95% CI:.08.39); 10-12 years: B = 0.13, (95% CI:.03.23); 12-14 years: B = 0.17, (95% CI:.07, 26)). The revealed relationships were significantly stronger in boys compared to the (absent) relations in girls. Sensitivity analyses examining moderate to vigorous PA (MVPA) rather than total PA were in accordance with the main findings.

CONCLUSIONS

In boys, increased FMI predicted reduced PA and increased ST two years later from childhood to adolescence. The opposite direction of influence was evident from only ages 12-14. There were no prospective relationships between FMI and PA or ST among girls.

The Current State of Optical Sensors in Medical Wearables

Optical sensors play an increasingly important role in the development of medical diagnostic devices. They can be very widely used to measure the physiology of the human body. Optical methods include PPG, radiation, biochemical, and optical fiber sensors. Optical sensors offer excellent metrological properties, immunity to electromagnetic interference, electrical safety, simple miniaturization, the ability to capture volumes of nanometers, and non-invasive examination. In addition, they are cheap and resistant to water and corrosion. The use of optical sensors can bring better methods of continuous diagnostics in the comfort of the home and the development of telemedicine in the 21st century. This article offers a large overview of optical wearable methods and their modern use with an insight into the future years of technology in this field.

A randomized controlled trial of a community-based obesity intervention utilizing motivational interviewing and community resource mobilization for low-income families: Study protocol and baseline characteristics

Low-income, racially diverse families with one parent with obesity are at high risk for child obesity. Effective approaches to promote healthy behaviors and prevent additional weight gain in family members are needed. Motivational interviewing (MI) may assist families to engage, identify motivations for change and establish goals. However, families with limited resources face other barriers to goal achievement that may be addressed through connection with community organizations. This paper describes a unique protocol combining MI and community connection. This randomized controlled trial includes low-income families with one parent with obesity and at least one child aged 6 to 12 years. Families in the intervention group receive an innovative, 12-month intervention combining health coaching using MI to promote lifestyle behavior change goals and community resource mobilization to assist with basic needs and resources to aid goals. The study protocol is modeled on community-based participatory research principles. Data is collected at baseline, 6 months, 12 months, and 18 months include questionnaires, body measurements, and accelerometer data. For adults, primary outcomes are Body Mass Index (BMI), minutes of moderate to vigorous physical activity (MVPA), and hours of sedentary time per day. For children, primary outcomes are sedentary time, MVPA, and the Family Nutrition and Physical Activity Score. From this hard-to-reach population, 236 diverse families were recruited. If the study is deemed effective, it has the potential to demonstrate that the combination of MI, resource mobilization, and utilization of existing community organizations is a sustainable model to assist families at risk for obesity.

Evaluation of Sedentary Behavior and Physical Activity Levels Using Different Accelerometry Protocols in Children from the GENOBOX Study

Background

Physical activity (PA) has acquired a significant relevance due to the health benefits associated with its practice. Accelerometers are an effective tool to assess PA; however, the diversity of cut-off points used to define different PA intensities through accelerometry could interfere in the interpretation of the findings among studies.

Objectives

The present study aimed to examine the sedentary behavior (SB) and physical activity (PA) levels in children using six selected accelerometry protocols based on diverse cut-off points.

Methods

Clinical examination, anthropometric measurements, and PA evaluation by accelerometry were assessed in 543 selected children (10 ± 2.4 years old) from the Spanish GENOBOX study. The ActiLife data scoring program was used to determine daily min spent in SB, and light, moderate, vigorous and moderate-vigorous PA using six validated accelerometry protocols differing in their cut-off points.

Results

Very different estimations for SB and PA intensity levels were found in children, independently of the non-wear-time algorithm selected, and considering puberty stages, age and body mass index. The time spent in daily SB varied from 471 to 663.7 min, PA ranged from 141 to 301.6 min, and the moderate-vigorous PA was reported between 20.7 and 180.2 min.

Conclusion

The choice of a particular accelerometry protocol considering these factors is important to evaluate SB or PA intensities to suit the characteristics of the sample researched. It seems necessary to establish future lines of research that include different analytical approaches to measure SB and PA by accelerometry based on standardized and validated methodology.

Dynamic testing to determine and predict trampoline function

Safety standards for domestic trampolines are based on static-load testing using a factor of five times the maximum intended user mass. This paper presents a dynamic test method for trampolines, and provides measures of the users’ performance (e.g., peak acceleration, Accmax) and injury risk (e.g., mean rate of change of acceleration, Jerkmean). Uniform masses (41–116 kg) were dropped from 0.66 m onto the bed centre of nineteen different trampolines. Trampoline bed and spring stretches, mass flight time (FlightT) and accelerations were recorded using motion capture and accelerometers. Thirty-seven percent of trampolines exceeded the static safety standard bed deformation limits (80% of frame height) by 11 ± 6% with dynamic testing (mean ± standard deviation). Across all trampolines and masses dropped, the Accmax ranged from 5.1 to 7.6 g, suggesting the factor of five used in static-loading safety standards needs reviewing. Statistically significant negative correlations (p < 0.05) were found between trampoline bed diameter and Accmax (r =  – 0.88), Jerkmean (r =  – 0.77) and FlightT (r =  – 0.82). Furthermore, significant correlations (p < 0.05) were also found between the mass dropped and Accmax (r =  – 0.27), Jerkmean (r =  – 0.59) and FlightT (r = 0.25). The combined effects of the spring constants, number of springs, bed diameters and masses dropped were described in predictive multivariate equations for Accmax (explained variance, R2 = 95%) and maximum vertical bed deformation (R2 = 85%). These findings from dynamic testing may assist manufacturers in designing trampolines that meet safety standards while maximising user performance and reducing injury risk.

Factors associated with validity of consumer-oriented wearable physical activity trackers: a meta-analysis

The purposes of this study were to examine (1) the strength of the criterion validity evidence of various consumer-oriented wearable physical activity trackers, (2) the influence of brands of consumer-oriented wearable physical activity on validity evidence and (3) factors that may contribute to differences in the strength of the criterion validity evidence. A total of 589 articles were identified through four databases. Pairs of researchers reviewed the articles to determine eligibility. A total of 29 studies with 96 validity coefficients were included in the meta-analysis. Five different moderators, including the brands of physical activity trackers, placement of devices, type of activities (ambulatory vs. lifestyle activities), population, and release year, were analysed to examine which factors impact the validity evidence. The summarised validity coefficient between activity trackers and energy expenditure ranged from r = .41 to r = .91. Moderator analyses revealed that the brand, placement of the device, and population significantly impact the magnitude of the validity evidence, while the type of activity and release year of the devices do not. Device brand, population, andplacement are each factor that significantly affects the validity coefficientsbetween consumer-oriented wearable physical activity trackers. Efforts should be made to improve the accuracy of these devices to maintain the credibility of the research and the trust of consumers.

Associations of Physical Activity and Sedentary Behaviour Assessed by Accelerometer with Body Composition among Children and Adolescents: A Scoping Review

The possible adverse health effects of reduced physical activity (PA) on children and adolescents have been extensively documented as a result of the global obesity epidemic. However, the research has sometimes led to controversial results, due to the different methods used for the assessment of PA. The main aim of this review was to evaluate the association between PA and body composition parameters based on quantitative PA studies using the same equipment (Actigraph accelerometer) and cutoffs (Evenson’s). A literature review was undertaken using PUBMED and Scopus databases. Subjects aged 6–15 were considered separately by sex. Weighted multiple regression analyses were conducted. From the analysis of fourteen selected articles, it emerged that 35.7% did not evaluate the association of sedentary time (ST) and moderate-to-vigorous physical activity (MVPA) with body composition, while the remaining 64.3% found a negative association of MVPA with BMI and fat mass with different trends according to sex. Furthermore, only 7.1% of these studies identified a positive association between ST and fat percentage. Based on the regression analyses conducted on the literature data, ST and MVPA were found to be significant predictors of body composition parameters, in addition to age and sex. Further studies using standardized methodologies to assess PA and body composition are needed. The inclusion of sex-disaggregated data may also be crucial to understand this phenomenon and to provide stronger evidence of the determinants of body composition in order to prevent the risk of obesity.

Can School-Based Physical Activity Projects Such as Skipping Hearts Have a Long-Term Impact on Health and Health Behavior?

Low physical activity, limited motor skills, and an increased number of overweight or obese children are major public health problems. Numerous school-based programs try to improve physical activity and health behavior in children but investigations on sustainable effects of these programs are rare. Therefore, we examined the long-term effects of the Skipping Hearts health promotion project. 486 children (57.7% female, 9.0 ± 0.6 years at baseline) participated in this non-randomized controlled longitudinal trial within a follow-up period of 3.5 years. Of these, 286 subjects received a one-time 90-min workshop in rope skipping (Basic-Workshop) and 140 additionally received 10 lessons in rope skipping (Champion-Program), 78 students served as controls. Anthropometrics, blood pressure, motor skills, screen-based media use, self-assessment of physical fitness, and physical activity were collected at both measurement points; endurance capacity and health-related quality of life only at follow-up. Standard deviation scores of body-mass-index (η2 = 0.005) and systolic blood pressure (η2 = 0.006) decreased, while diastolic blood pressure (η2 = 0.004), motor performance (η2 < 0.001), physical fitness, subjective physical activity (η2 = 0.008), and screen-based media use (η2 = 0.001) increased without significant difference in development between groups (all p > 0.05). At follow-up, groups did not differ in endurance capacity (η2 = 0.010) and health-related quality of life (η2 < 0.001). Skipping Hearts does not affect the long-term improvement of health status, motor performance, or health behavior. To improve the effects, the project should be implemented as a daily routine in schools to force the transfer of health behavior-related knowledge. Nevertheless, the project offers a physical activity that can be performed in children's everyday life without high costs.

Application of Modern Multi-Sensor Holter in Diagnosis and Treatment

Modern Holter devices are very trendy tools used in medicine, research, or sport. They monitor a variety of human physiological or pathophysiological signals. Nowadays, Holter devices have been developing very fast. New innovative products come to the market every day. They have become smaller, smarter, cheaper, have ultra-low power consumption, do not limit everyday life, and allow comfortable measurements of humans to be accomplished in a familiar and natural environment, without extreme fear from doctors. People can be informed about their health and 24/7 monitoring can sometimes easily detect specific diseases, which are normally passed during routine ambulance operation. However, there is a problem with the reliability, quality, and quantity of the collected data. In normal life, there may be a loss of signal recording, abnormal growth of artifacts, etc. At this point, there is a need for multiple sensors capturing single variables in parallel by different sensing methods to complement these methods and diminish the level of artifacts. We can also sense multiple different signals that are complementary and give us a coherent picture. In this article, we describe actual interesting multi-sensor principles on the grounds of our own long-year experiences and many experiments.

Improvement of exercise capacity following neonatal respiratory failure: A randomized controlled trial

Exercise capacity deteriorates in school-aged children born with major anatomical foregut anomalies and/or treated with extracorporeal membrane oxygenation. The aim of the present study was to evaluate whether exercise capacity can be improved in the short term and long term in children born with anatomical foregut anomalies and/or treated with extracorporeal membrane oxygenation. Therefore, we evaluated two different interventions in this single-blinded randomized controlled trial. Forty participants were randomly assigned to group A: standardized anaerobic high-intensity interval training plus online lifestyle coaching program, B: online lifestyle coaching program only, or C: standard of care. Inclusion criteria were as follows: score ≤-1 standard deviation (SD) on the Bruce protocol. Exercise capacity was assessed at baseline (T0), after 3 months (T1), and after 12 months (T2). Exercise capacity improved over time: mean (SD) standard deviation score (SDS) endurance time: T0 -1.91 (0.73); T1 -1.35 (0.94); T2 -1.20 (1.03): both P < .001. No significant differences in maximal endurance time were found at T1 (group A-C: estimated mean difference (SDS): 0.06 P = .802; group B-C: -0.17 P = .733) or T2 (group A-C: -0.13 P = .635; group B-C: -0.18 P = .587). Exercise capacity improved significantly over time, irrespective of the study arm. Not only residual morbidities may be responsible for reduced exercise capacity. Parental awareness of reduced exercise capacity rather than specific interventions may have contributed. Monitoring of exercise tolerance and providing counseling on lifestyle factors that improve physical activity should be part of routine care, and aftercare should be offered on an individual basis.

The Tangibility of Personalized 3D-Printed Feedback May Enhance Youths' Physical Activity Awareness, Goal Setting, and Motivation: Intervention Study

BACKGROUND

In the United Kingdom, most youth fail to achieve the government guideline of 60 min of moderate to vigorous physical activity (MVPA) daily. Reasons that are frequently cited for the underachievement of this guideline include (1) a lack of awareness of personal physical activity levels (PALs) and (2) a lack of understanding of what activities and different intensities contribute to daily targets of physical activity (PA). Technological advances have enabled novel ways of representing PA data through personalized tangible three-dimensional (3D) models.

OBJECTIVE

The purpose of this study was to investigate the efficacy of 3D-printed models to enhance youth awareness and understanding of and motivation to engage in PA.

METHODS

A total of 39 primary school children (22 boys; mean age 7.9 [SD 0.3] years) and 58 secondary school adolescents (37 boys; mean age 13.8 [SD 0.3] years) participated in a 7-week fading intervention, whereby participants were given 3D-printed models of their previous week's objectively assessed PALs at 4 time points. Following the receipt of their 3D model, each participant completed a short semistructured video interview (children, 4.5 [SD 1.2] min; adolescents, 2.2 [SD 0.6] min) to assess their PA awareness, understanding, and motivation. Data were transcribed verbatim and thematically analyzed to enable key emergent themes to be further explored and identified.

RESULTS

Analyses revealed that the 3D models enhanced the youths' awareness of and ability to recall and self-evaluate their PA behaviors. By the end of the study, the youths, irrespective of age, were able to correctly identify and relate to the government's PA guideline represented on the models, despite their inability to articulate the government's guideline through time and intensity. Following the fourth 3D model, 72% (71/97) of the youths used the models as a goal-setting strategy, further highlighting such models as a motivational tool to promote PA.

CONCLUSIONS

The results suggest that 3D-printed models of PA enhanced the youths' awareness of their PA levels and provided a motivational tool for goal setting, potentially offering a unique strategy for future PA promotion.

A semiparametric model for wearable sensor-based physical activity monitoring data with informative device wear

Wearable sensors provide an exceptional opportunity in collecting real-time behavioral data in free living conditions. However, wearable sensor data from observational studies often suffer from information bias, since participants' willingness to wear the monitoring devices may be associated with the underlying behavior of interest. The aim of this study was to introduce a semiparametric statistical approach for modeling wearable sensor-based physical activity monitoring data with informative device wear. Our simulation study indicated that estimates from the generalized estimating equations showed ignorable bias when device wear patterns were independent of the participants physical activity process, but incrementally more biased when the patterns of device non-wear times were increasingly associated with the physical activity process. The estimates from the proposed semiparametric modeling approach were unbiased both when the device wear patterns were (i) independent or (ii) dependent to the underlying physical activity process. We demonstrate an application of this method using data from the 2003-2004 National Health and Nutrition Examination Survey ($N=4518$), to examine gender differences in physical activity measured using accelerometers. The semiparametric model can be implemented using our R package acc, free software developed for reading, processing, simulating, visualizing, and analyzing accelerometer data, publicly available at the Comprehensive R Archive Network.

Uni- and triaxial accelerometric signals agree during daily routine, but show differences between sports

Accelerometers objectively monitor physical activity, and ongoing research suggests they can also detect patterns of body movement. However, different types of signal (uniaxial, captured by older studies, vs. the newer triaxial) and or/device (validated Actigraph used by older studies, vs. others) may lead to incomparability of results from different time periods. Standardization is desirable. We establish whether uniaxial signals adequately monitor routine activity, and whether triaxial accelerometry can detect sport-specific variations in movement pattern. 1402 adolescents wore triaxial Actigraphs (GT3X) for one week and diaried sport. Uni- and triaxial counts per minute were compared across the week and between over 30 different sports. Across the whole recording period 95% of variance in triaxial counts was explained by the vertical axis (5th percentile for R², 91%). Sport made up a small fraction of daily routine, but differences were visible: even when total acceleration was comparable, little was vertical in horizontal movements, such as ice skating (uniaxial counts 41% of triaxial) compared to complex movements (taekwondo, 55%) or ambulation (soccer, 69%). Triaxial accelerometry captured differences in movement pattern between sports, but so little time was spent in sport that, across the whole day, uni- and triaxial signals correlated closely. This indicates that, with certain limitations, uniaxial accelerometric measures of routine activity from older studies can be feasibly compared to triaxial measures from newer studies. Comparison of new studies based on raw accelerations to older studies based on proprietary devices and measures (epochs, counts) will require additional efforts which are not addressed in this paper.

Randomised controlled trial evaluating the effectiveness and cost-effectiveness of 'Families for Health', a family-based childhood obesity treatment intervention delivered in a community setting for ages 6 to 11 years

BACKGROUND

Effective programmes to help children manage their weight are required. 'Families for Health' focuses on a parenting approach, designed to help parents develop their parenting skills to support lifestyle change within the family. Families for Health version 1 showed sustained reductions in mean body mass index (BMI) z-score after 2 years in a pilot project.

OBJECTIVE

The aim was to evaluate its effectiveness and cost-effectiveness in a randomised controlled trial (RCT).

DESIGN

The trial was a multicentre, investigator-blind RCT, with a parallel economic and process evaluation, with follow-up at 3 and 12 months. Randomisation was by family unit, using a 1 : 1 allocation by telephone registration, stratified by three sites, with a target of 120 families.

SETTING

Three sites in the West Midlands, England, UK.

PARTICIPANTS

Children aged 6-11 years who were overweight (≥ 91st centile BMI) or obese (≥ 98th centile BMI), and their parents/carers. Recruitment was via referral or self-referral.

INTERVENTIONS

Families for Health version 2 is a 10-week, family-based community programme with parallel groups for parents and children, addressing parenting, lifestyle, social and emotional development. Usual care was the treatment for childhood obesity provided within each locality.

MAIN OUTCOME MEASURES

Joint primary outcome measures were change in children's BMI z-score and incremental cost per quality-adjusted life-year (QALY) gained at 12 months' follow-up (QALYs were calculated using the European Quality of Life-5 Dimensions Youth version). Secondary outcome measures included changes in children's waist circumference, percentage body fat, physical activity, fruit/vegetable consumption and quality of life. Parents' BMI and mental well-being, family eating/activity, parent-child relationships and parenting style were also assessed. The process evaluation documented recruitment, reach, dose delivered, dose received and fidelity, using mixed methods.

RESULTS

The study recruited 115 families (128 children; 63 boys and 65 girls), with 56 families randomised to the Families for Health arm and 59 to the 'usual-care' control arm. There was 80% retention of families at 3 months (Families for Health, 46 families; usual care, 46 families) and 72% retention at 12 months (Families for Health, 44 families; usual care, 39 families). The change in BMI z-score at 12 months was not significantly different in the Families for Health arm and the usual-care arm [0.114, 95% confidence interval (CI) -0.001 to 0.229; p = 0.053]. However, within-group analysis showed that the BMI z-score was significantly reduced in the usual-care arm (-0.118, 95% CI -0.203 to -0.034; p = 0.007), but not in the Families for Health arm (-0.005, 95% CI -0.085 to 0.078; p = 0.907). There was only one significant difference between groups for secondary outcomes. The economic evaluation, taking a NHS and Personal Social Services perspective, showed that mean costs 12 months post randomisation were significantly higher for Families for Health than for usual care (£998 vs. £548; p < 0.001). The mean incremental cost-effectiveness of Families for Health was estimated at £552,175 per QALY gained. The probability that the Families for Health programme is cost-effective did not exceed 40% across a range of thresholds. The process evaluation demonstrated that the programme was implemented, as planned, to the intended population and any adjustments did not deviate widely from the handbook. Many families waited more than 3 months to receive the intervention. Facilitators', parents' and children's experiences of Families for Health were largely positive and there were no adverse events. Further analysis could explore why some children show a clinically significant benefit while others have a worse outcome.

CONCLUSIONS

Families for Health was neither effective nor cost-effective for the management of obesity in children aged 6-11 years, in comparison with usual care. Further exploration of the wide range of responses in BMI z-score in children following the Families for Health and usual-care interventions is warranted, focusing on children who had a clinically significant benefit and those who showed a worse outcome with treatment. Further research could focus on the role of parents in the prevention of obesity, rather than treatment.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN45032201.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 21, No. 1. See the NIHR Journals Library website for further project information.

Accelerometric estimates of physical activity vary unstably with data handling

Background

Because of unreliable self-report, accelerometry is increasingly used to objectively monitor physical activity (PA). However, results of accelerometric studies vary depending on the chosen cutpoints between activity intensities. Population-specific activity patterns likely affect the size of these differences. To establish their size and stability we apply three sets of cutpoints, including two calibrated to a single reference, to our accelerometric data and compare PA estimates.

Methods

1402 German adolescents from the GINIplus and LISAplus cohorts wore triaxial accelerometers (Actigraph GT3x) for one week (mean 6.23 days, 14.7 hours per day) at the hip. After validation of wear, we applied three sets of cutpoints for youth, including the most common standard (Freedson, 2005) and two calibrated to a single reference, (Romanzini uni- and triaxial, from Romanzini, 2014) to these data, estimating daily sedentary, light, moderate, vigorous and moderate-to-vigorous PA (MPA, VPA, MVPA). Stability of differences was assessed by comparing Romanzini’s two sets of cutpoints.

Results

Relative agreement between cutpoints was closer for activity of lower intensities (largest difference for sedentary behaviour 9%) but increased for higher intensities (largest difference for light activity 40%, MPA 102%, VPA 88%; all p<0.01). Romanzini’s uniaxial and triaxial cutpoints agreed no more closely with each other than with Freedson’s.

Conclusions

Estimated PA differed significantly between different sets of cutpoints, even when those cutpoints agreed perfectly on another dataset (i.e. Romanzini’s.) This suggests that the detected differences in estimated PA depend on population-specific activity patterns, which cannot be easily corrected for: converting activity estimates from one set of cutpoints to another may require access to raw data. This limits the utility of accelerometry for comparing populations in place and time. We suggest that accelerometric research adopt a standard for data processing, and apply and present the results of this standard in addition to those from any other method.

The effects of a low-dose physical activity intervention on physical activity and body mass index in severely obese adolescents

Background While severe obesity in childhood poses the greatest long-term health risks, access to treatment is a common barrier. The present pilot study examined the effect of a 7-week low-dose physical activity (PA) intervention on PA and body mass index (BMI) in severe obese adolescents delivered via telephone and mail. Methods Adolescents (n = 64) receiving care from a pediatric obesity medical clinic were randomized to a control (n = 30) or intervention (n = 34) group. Height and weight were measured and BMI z-scores were calculated. PA was assessed by a pedometer. All measurements were completed pre- and post-intervention. The intervention group received weekly newsletters and telephone calls discussing various PA topics based on motivational interviewing for 7 weeks. The control group received no contact. A series of 2 × 2 (group by time) repeated measures analysis of covariances (ANCOVAs) adjusting for length of time between visits were performed to examine the effect of the intervention on PA and BMI z-scores. Results The majority of adolescents were severely obese (77%, BMI: > 99th percentile). Intention-to-treat analysis revealed intervention effects were not observed for either pedometer steps or BMI z-score (p > 0.05). Among those with complete data, adolescents who successfully changed their BMI z-score had larger BMI z-score changes than those who did not change their BMI z-score (p = 0.0001). This improvement was due to something other than PA as the change in BMI z-score was similar among those who did and did not successfully increase PA levels (p > 0.05). Conclusions More intensive, comprehensive, and longer-term treatment is needed in this high risk population.

Feasibility and adherence paradigm to ecological momentary assessments in urban minority youth

All adolescents in general, including ethnic and racial minorities, report high levels of cell phone use, making mobile technology a useful tool for assessment and intervention. Known health and education disparities based on minority status motivated us to conduct an in-depth investigation regarding feasibility of and adherence to the ecological momentary assessment (EMA) research protocol, studying daily life of urban minority youth. In addition, this paper presents a methodological approach to conceptualizing and reporting adherence in EMA studies. The sample was comprised of 126 youth (41.3% boys; 40.5% 7th and 59.5% 8th graders; 75.4% African American, and 20.6% Hispanic) who carried a mobile phone for 10 days, including 2 weekends and reported on activities, moods, and attitudes. Mean level of adherence was 81% for momentary and 93.8% for daily assessments; it decreased over time and was higher during the week compared to weekends. Adherence was lower on days when participants reported high levels of negative affect and on days when they were engaged in physical activities. Our findings underscore the importance of differentiating between human and technology-related factors when computing adherence rates and portray adherence as a complex and dynamic construct that can vary across individuals. Specific study recommendations and methodological discussion provide guidelines for designing future studies. (PsycINFO Database Record

Assessment of pedometer accuracy in capturing habitual types of physical activities in overweight and obese children

BACKGROUND

Currently, there is a limited amount of research exploring physical activity measurement tools in overweight and obese (OW/OB) children using pedometers. Thus, our objective was to determine the accuracy of one spring-levered (SC-T2) and two piezoelectric pedometers (NL-1000 and Piezo) in OW/OB children.

METHODS

A total of 26 boys and 34 girls (n = 60) participated. Pedometer step-counts were compared to observed step counts for walking (walking, stair ascent and decent) and hopping tests. Pedometer accuracies were compared with Friedman tests while Bland-Altman plots were used to establish the accuracy of each pedometer against direct observations.

RESULTS

Boys (n = 26) and females (n = 34) were 96 and 91% OB, respectively. The two piezoelectric pedometers (NL-1000 and Piezo) were accurate for walking and stair climbing tasks, however all pedometers were inaccurate for hopping tests. Averaged over all three walking activities, the NL-1000 was the most accurate with 6.7% median error (interquartile range (IQR): 0.0-13.3); followed by the Piezo with 10.0% median error (IQR: 3.3-18.1); SC-T2 was the least accurate with -14.7% median error (IQR: -54.8-3.5).

CONCLUSION

These results support the use of the piezoelectric pedometers for walking and stair climbing types of activities, which are typical for OW/OB children in a nonlaboratory setting.

Children's GPS-determined versus self-reported transport in leisure time and associations with parental perceptions of the neighborhood environment

Background

This study aimed to examine both GPS-determined and self-reported walking, cycling and passive transport in leisure time during week- and weekend-days among 10 to 12-year old children. Comparisons between GPS-determined and self-reported transport in leisure time were investigated. Second, associations between parental perceptions of the neighborhood environment and GPS-determined walking, cycling and passive transport in leisure time were studied.

Methods

Children (10 to 12-years old; n = 126) wore a GPS device and an accelerometer for 7 consecutive days to assess objectively measured transport in leisure time and filled out a diary to assess self-reported transport in leisure time. Parents completed a questionnaire to assess parental perceptions of the neighborhood environment. Pearson correlations and t-tests were used to test for concurrent validity and differences between GPS-determined and self-reported transport in leisure time. Generalized linear models were used to determine the associations between the parental perceptions of the neighborhood environment and GPS-determined transport in leisure time.

Results

Overall, children under-reported their walking and cycling in leisure time, compared to GPS-determined measures (all p values <0.001). However, children reported their passive transport in leisure time during weekend days quite accurate. GPS-determined measures revealed that children walked most during weekdays (M = 3.96 trips/day; 26.10 min/day) and used passive transport more frequently during weekend days (M = 2.12 trips/day; 31.39 min/day). Only a few parental perceived environmental attributes of the neighborhood (i.e. residential density, land use mix access, quality and availability of walking and cycling facilities, and aesthetics) were significantly associated with children’s GPS-determined walking, cycling or passive transport in leisure time.

Conclusions

To accurately assess children’s active transport in leisure time, GPS measures are recommended over self-reports. More research using GPS with a focus on children’s transport in leisure time and investigating the associations with parental perceptions of the neighborhood environment is needed to confirm the results of the present study.

Electronic supplementary material

The online version of this article (doi:10.1186/s12942-016-0045-9) contains supplementary material, which is available to authorized users.

Gamification of active travel to school: A pilot evaluation of the Beat the Street physical activity intervention

Beat the Street aims to get children more active by encouraging them to walk and cycle in their neighbourhood using tracking technology with a reward scheme. This pilot study evaluates the impact of Beat the Street on active travel to school in Norwich, UK. Eighty children 8-10 yrs were recruited via an intervention and control school. They wore an accelerometer for 7 days at baseline, mid-intervention and post-intervention (+20 weeks), and completed a travel diary. Physical activity overall was not higher at follow-up amongst intervention children compared to controls. However, there was a positive association between moderate-to-vigorous physical activity (MVPA) during school commute times and the number of days on which children touched a Beat the Street sensor. This equated to 3.46min extra daily MVPA during commute times for children who touched a sensor on 14.5 days (the mean number of days), compared to those who did not engage. We also found weekly active travel increased at the intervention school (+10.0% per child) while it decreased at the control (-7.0%), p=0.056. Further work is needed to understand how improved engagement with the intervention might impact outcomes.

Physical Activity Levels and Domains Assessed by Accelerometry in German Adolescents from GINIplus and LISAplus

BACKGROUND

Physical activity (PA) is a well-known and underused protective factor for numerous health outcomes, and interventions are hampered by lack of objective data. We combined accelerometers with diaries to estimate the contributions to total activity from different domains throughout the day and week in adolescents.

METHODS

Accelerometric and diary data from 1403 adolescents (45% male, mean age 15.6 ± 0.5 years) were combined to evaluate daily levels and domains of sedentary, light, and moderate-to-vigorous activity (MVPA) during a typical week. Freedson's cutoff points were applied to determine levels of activity. Total activity was broken down into school physical education (PE), school outside PE, transportation to school, sport, and other time.

RESULTS

About 2/3 of adolescents' time was spent sedentary, 1/3 in light activity, and about 5% in MVPA. Boys and girls averaged 46 (SD 22) and 38 (23) minutes MVPA per day. Adolescents were most active during leisure sport, spending about 30% of it in MVPA, followed by PE (about 20%) transport to school (14%) and either school class time or other time (3%). PE provided 5% of total MVPA, while leisure sport provided 16% and transportation to school 8%. School was the most sedentary part of the day with over 75% of time outside PE spent sedentary.

CONCLUSIONS

These German adolescents were typical of Europeans in showing low levels of physical activity, with significant contributions from leisure sport, transportation and school PE. Leisure sport was the most active part of the day, and participation did not vary significantly by sex, study center (region of Germany) or BMI. Transportation to school was frequent and thus accounted for a significant fraction of total MVPA. This indicates that even in a population with good access to dedicated sporting activities, frequent active transportation can add significantly to total MVPA.

Physical activity is not associated with spirometric indices in lung-healthy German youth

In lung disease, physical activity improves lung function and reduces morbidity. However, healthy populations are not well studied. We estimate the relationship between spirometric indices and accelerometric physical activity in lung-healthy adolescents.895 nonsmoking German adolescents without chronic lung disease (45% male, mean±sd age 15.2±0.26 years) from the GINIplus and LISAplus cohorts completed questionnaires, spirometry, 7-day accelerometry and an activity diary. Physical activity was measured as minutes, quintiles and regularity of daily moderate, vigorous and moderate-to-vigorous physical activity (MVPA), participation in sport and active commuting to school. Primary outcomes were forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), FEV1/FVC and forced expiratory flow at 25-75% of FVC; they were separately correlated with physical activity and adjusted for confounders of respiratory function, including early-life exposures.Adolescents averaged 40 min MVPA per day, typical for European youth. 79% participated in sports and 51% commuted actively. An association was suggested between 3% higher FVC (∼100 mL) and either extreme MVPA quintile or percentage of days with >30 min MVPA (p<0.05). However, after Bonferroni correction all associations between spirometry, active lifestyle and physical activity were nonsignificant.Spirometric indices were not significantly associated with active lifestyle or measures of activity in lung-healthy adolescents after adjustment for confounding and multiple-comparison artefacts.

Validity and practical utility of accelerometry for the measurement of in-hand physical activity in horses

Background

Accelerometers are valid, practical and reliable tools for the measurement of habitual physical activity (PA). Quantification of PA in horses is desirable for use in research and clinical settings. The objective of this study was to evaluate a triaxial accelerometer for objective measurement of PA in the horse by assessment of their practical utility and validity.

Horses were recruited to establish both the optimal site of accelerometer attachment and questionnaire designed to explore owner acceptance. Validity and cut-off values were obtained by assessing PA at various gaits. Validation study- 20 horses wore the accelerometer while being filmed for 10 min each of rest, walking and trotting and 5 mins of canter work. Practical utility study- five horses wore accelerometers on polls and withers for 18 h; compliance and relative data losses were quantified.

Results

Accelerometry output differed significantly between the four PA levels (P < 0•001) for both wither and poll placement. For withers placement, ROC analyses found optimal sensitivity and specificity at a cut-off of <47 counts per minute (cpm) for rest (sensitivity 99.5 %, specificity 100 %), 967–2424 cpm for trotting (sensitivity 96.7 %, specificity 100 %) and ≥2425 cpm for cantering (sensitivity 96.0 %, specificity 97.0 %). Attachment at the poll resulted in optimal sensitivity and specificity at a cut-off of <707 counts per minute (cpm) for rest (sensitivity 97.5 %, specificity 99.6 %), 1546–2609 cpm for trotting (sensitivity 90.33 %, specificity 79.25 %) and ≥2610 cpm for cantering (sensitivity 100 %, specificity 100 %) In terms of practical utility, accelerometry was well tolerated and owner acceptance high.

Conclusion

Accelerometry data correlated well with varying levels of in-hand equine activity. The use of accelerometers is a valid method for objective measurement of controlled PA in the horse.

Reliability and Validity of the Self- and Interviewer-Administered Versions of the Global Physical Activity Questionnaire (GPAQ)

Objective

The Global Physical Activity Questionnaire (GPAQ) was originally designed to be interviewer-administered by the World Health Organization in assessing physical activity. The main aim of this study was to compare the psychometric properties of a self-administered GPAQ with the original interviewer-administered approach. Additionally, this study explored whether using different accelerometry-based physical activity bout definitions might affect the questionnaire’s validity.

Methods

A total of 110 participants were recruited and randomly allocated to an interviewer- (n = 56) or a self-administered (n = 54) group for test-retest reliability, of which 108 participants who met the wear time criteria were included in the validity study. Reliability was assessed by administration of questionnaires twice with a one-week interval. Criterion validity was assessed by comparing against seven-day accelerometer measures. Two definitions for accelerometry-data scoring were employed: (1) total-min of activity, and (2) 10-min bout.

Results

Participants had similar baseline characteristics in both administration groups and no significant difference was found between the two formats in terms of validity (correlations between the GPAQ and accelerometer). For validity, the GPAQ demonstrated fair-to-moderate correlations for moderate-to-vigorous physical activity (MVPA) for self-administration (r_s = 0.30) and interviewer-administration (r_s = 0.46). Findings were similar when considering 10-min activity bouts in the accelerometer analysis for MVPA (r_s = 0.29 vs. 0.42 for self vs. interviewer). Within each mode of administration, the strongest correlations were observed for vigorous-intensity activity. However, Bland-Altman plots illustrated bias toward overestimation for higher levels of MVPA, vigorous- and moderate-intensity activities, and underestimation for lower levels of these measures. Reliability for MVPA revealed moderate correlations (r_s = 0.61 vs. 0.63 for self vs. interviewer).

Conclusions

Our findings showed comparability between both self- and interviewer-administration modes of the GPAQ. The GPAQ in general but especially the self-administered version may offer a relatively inexpensive method for measuring physical activity of various types and at different domains. However, there may be bias in the GPAQ measurements depending on the overall physical activity. It is advisable to incorporate accelerometers in future studies, particularly when measuring different intensities of physical activity.

A feasibility study of wearable activity monitors for pre-adolescent school-age children

Introduction

Understanding physical activity is key in the fight against childhood obesity. The objective of this study was to examine the feasibility of using certain wearable devices to measure physical activity among children.

Methods

A qualitative study was conducted with 25 children aged 7 to 10 years to assess acceptability and compliance of wearable activity devices in this age group. During March through August 2012, children participated in a 4-week study of 3 accelerometer models and a heart rate monitor. Children were asked to use a different device each week for 7 consecutive days. Children and their parents completed structured interviews after using each device; they also completed a final exit interview.

Results

The wrist-worn Polar Active was the device most preferred by children and was associated with the highest level of compliance. Devices that are comfortable to wear, fit properly, have engaging features, and are waterproof increase feasibility and are associated with higher levels of compliance.

Conclusion

The wrist-worn device was the most feasible for measuring physical activity among children aged 7 to 10 years. These findings will inform researchers in selecting tools for measuring children’s physical activity.

Physical activity assessment tools for use in overweight and obese children

The prevalence of excess weight in children and adults worldwide has increased rapidly in the last 25 years. Obesity is positively associated with increased risk for many health issues such as type 2 diabetes, cardiovascular disease and psychosocial problems. This review focuses on child populations, as it is known that the sedentary behaviors of overweight/obese youth often endure into adulthood. Assessment of physical activity (PA), among other factors such as diet and socio-economic status, is important in understanding weight variation and in designing interventions. This review highlights common subjective and objective PA assessment tools, the validity of these methods and acceptable ways of collecting and interpreting PA data. The aim is to provide an update on PA assessment in overweight/obese children, highlighting current knowledge and any gaps in the literature, in order to facilitate the use of PA assessments and interventions by health-care professionals as well as suggest future research in this area.

Objectively measured physical activity levels of children and adolescents in rural South Africa: high volume of physical activity at low intensity

There is limited evidence on objectively measured physical activity from Africa. This study quantified physical activity by accelerometry in rural South African children at ages 7, 11, and 15 years. Total physical activity was generally high (mean accelerometer counts per minute ranged 485-1017 across the 3 groups), but moderate- to vigorous-intensity physical activity was low: <1% of the sample met international recommendations. A low intensity, high volume of physical activity is present in rural South African children and adolescents.

Young People's Views on Accelerometer Use in Physical Activity Research: Findings from a User Involvement Investigation

The use of accelerometers to objectively measure physical activity is important in understanding young people's behaviours, as physical activity plays a key part in obesity prevention and treatment. A user-involvement qualitative study with young people aged 7–18 years (n = 35) was carried out to investigate views on accelerometer use to inform an obesity treatment research study. First impressions were often negative, with issues related to size and comfort reported. Unwanted attention from wearing an accelerometer and bullying risk were also noted. Other disadvantages included feeling embarrassed and not being able to wear the device for certain activities. Positive aspects included feeling “special” and having increased attention from friends. Views on the best time to wear accelerometers were mixed. Advice was offered on how to make accelerometers more appealing, including presenting them in a positive way, using a clip rather than elastic belt to attach, personalising the device, and having feedback on activity levels. Judgements over the way in which accelerometers are used should be made at the study development stage and based on the individual population. In particular, introducing accelerometers in a clear and positive way is important. Including a trial wearing period, considering practical issues, and providing incentives may help increase compliance.

Objectively assessed physical activity and weight status in Maltese 11-12 year-olds

The objectives of the study were to identify levels of physical activity and sedentary time and assess how they differ by weight status in Maltese boys and girls. Participants were 234 Maltese children aged 11-12 years, of which 187 (80%) provided complete data. Physical activity was assessed using accelerometry and weight status determined through gender-specific age-adjusted Body mass index (BMI). Self-reported mode of transport to school, TV and computer time, gaming and mobile phone use were assessed by questionnaire. Total physical activity was generally very low and significantly lower for girls than boys at all times on weekdays and on weekends till 7 pm. Overweight and obesity prevalence was 27% and 18.6%, respectively. Differences in overall physical activity were observed between non-overweight, and overweight and obese boys (p=0.003). Differences in moderate to vigorous intensity physical activity (MVPA) in boys were significant across all weight categories (p=0.001) and in girls (p=0.020) between the overweight (27.6 min), the non-overweight (26.4 min) and the obese (18.9 min). For weekdays, mean physical activity differences (p=0.013) were observed between non-overweight (515.5 cpm) and obese boys (416.4 cpm). Differences in MVPA were found (p=0.038) between non-overweight (4.4 min) and obese boys in the 6 am-3 pm period. Differences were also found between overweight (13.2 min) and obese girls (8.1 min) (p=0.024) in that period. On weekends, mean physical activity differences were found between non-overweight and overweight boys from 8 am-7 pm but not for girls. Physical activity levels in this sample were very low when compared to recommended levels, while the prevalence of overweight and obesity and sedentary time were high. Girls are significantly less active than boys throughout the week. Activity level differences and patterning across the day and week were related to weight status with obese children showing markedly less activity. These results suggest that we need to provide more opportunities for overweight and obese children to be active throughout the week, with a particular emphasis on physical activity during school hours.