Development of the Food Boost Challenge: A Participatory Action Research Approach to Enhance Vegetable and Fruit Consumption among Adolescents.

Prevention of non-communicable diseases through, among other factors, increasing vegetables and fruit (V&F) intake is a cost-effective strategy for risk reduction but requires behavioral change. Such changes in adolescents benefit from their active involvement. The Food Boost Challenge (FBC) was developed using a participatory action research approach to enhance healthy eating behaviors, namely V&F products among adolescents. The FBC is an innovation process, involving adolescents, (peer) researchers, and food system partners, like non-governmental and commercial organizations. In 2021-2022, 34 partners provided both cash and in-kind contributions to join the FBC community. Phase 1 involved 200 students identifying barriers and drivers for consumption of F&V products among 1000 pre-vocational adolescents, aged 12-20 years. In phase 2, student teams submitted innovative ideas, resulting in 25 concepts fitting into ≥1 of 4 routes: (I) innovative technology for a healthy diet, (II) new food products/concepts for adolescents, (III) hotspots improving the F&V product experience, and (IV) new routes to market. In phase 3, consortia of adolescents, students, and partners were formed to develop 10 selected concepts into prototypes, and phase 4 offered teams a national platform. Results show that the FBC resonates with all stakeholders, generating valuable insights to increase F&V intake. Prototypes in all four routes have been developed. Additionally, other regions in the Netherlands have adopted the FBC approach. Overall, the FBC is an approach that transforms ideas into actionable measures and shows potential to be adapted to promote various healthy eating behaviors among school students.

Evaluation of a school-based multicomponent behavioural intervention in deprived urban areas for children classified as overweight, obese or at risk for overweight.

OBJECTIVE: This study evaluated the effect of an after-school group-based medium-intensity multicomponent behavioural intervention programme for children aged 8-12 years classified as overweight, obese or at risk for overweight on body mass index standard deviation score (BMI SDS). In accordance with standardized protocols body weight and height were measured in 195 participants (88 boys, 107 girls) at baseline and at the end of the programme. A total of 166 children derived from a school-based monitoring system served as control group. Multivariate regression analyses examined the effect of the intervention and the independent factors associated with better outcomes in the intervention group. RESULTS: Analysis of covariance showed a significant intervention effect on BMI SDS in favour of the intervention group (b-coefficient - 0.13 ± 0.03; p < 0.01) compared with the control group. Change in BMI SDS between baseline and follow-up in the intervention group was associated with baseline age (b-coefficient 0.03 ± 0.02; p = 0.04) but was independent from gender, ethnicity, baseline BMI SDS, time between baseline and follow-up, school year and attendance rate.

Understanding Vocational Students' Motivation for Dietary and Physical Activity Behaviors.

Unhealthy eating behaviors and low levels of physical activity are major problems in adolescents and young adults in vocational education. To develop effective intervention programs, more research is needed to understand how different types of motivation contribute to health behaviors. In the present study, Self-Determination Theory is used to examine how motivation contributes to dietary and physical activity behaviors in vocational students. This cross-sectional study included 809 students (mean age 17.8 ± 1.9 years) attending vocational education in the Netherlands. Linear multilevel regression analyses were used to investigate the association between types of motivation and dietary and physical activity behaviors. Amotivation was negatively associated with breakfast frequency and positively associated with diet soda consumption and high-calorie between-meal snacks. A positive association was found between autonomous motivation and water intake, breakfast frequency, fruit intake, and moderate-to-vigorous physical activity. Autonomous motivation was negatively associated with the consumption of unhealthy products. Controlled motivation was not associated with physical activity or dietary behaviors. Different types of motivation seem to explain either healthy or unhealthy dietary behaviors in vocational students. Autonomous motivation, in particular, was shown to be associated with healthy behaviors and could therefore be a valuable intervention target.

Investigating longitudinal context-specific physical activity patterns in transition from primary to secondary school using accelerometers, GPS, and GIS.

INTRODUCTION: Previous longitudinal studies indicate that physical activity (PA) significantly declines from primary-to secondary school, and report both changes in individual and environmental determinants of PA. In order to understand this transition and to prevent this negative trend, it is important to gather contextually rich data on possible mechanisms that drive this decline. Therefore, the aim of this study was to investigate changes of PA patterns in transition between primary and secondary school, and to add domain-specific insights of how, where, and when these changes occur. METHODS: In total, 175 children participated in a 7-day accelerometer- and Global Positioning System (GPS) protocol at their last year of primary and their first year of secondary school. GPS data-points were overlaid with Geographical Information Systems (GIS) data using ArcGIS 10.1 software. Based on the GPS locations of individual data-points, we identified child's PA at home, school, local sports grounds, shopping centers, and other locations. Also, trips in active and passive transport were identified according to previously validated GPS speed-algorithms. Longitudinal multi-level linear mixed models were fitted adjusting for age, gender, meteorological circumstances, and the nested structure of days within children and children within schools. Outcome measures were minutes spent in light PA and moderate-to-vigorous PA, specified for the time-segments before school, during school, after school and weekend days. RESULTS: Total PA significantly declined from primary to secondary school. Although transport-related PA increased before- and during school, decreases were found for especially afterschool time spent at sports grounds and transport-related PA during weekends. CONCLUSIONS: This is the first study that demonstrated longitudinal changes of context- and domain-specific PA patterns in transition between primary and secondary school, based on device-assessed PA. Given the importance of this transition-period for the development of long-term PA patterns, results from this study warrant the development of evidence-based PA programs in this transition period, while acknowledging the integrative role of schools, parents, and afterschool sports providers. More specifically, the results underline the need to increase children's PA levels in primary schools, promote afterschool PA at secondary schools, and to prevent the drop-out in sports participation at secondary schools.

Quality of Life: The Interplay between Human Behaviour, Technology and the Environment.

Quality of life is an umbrella term for the quality of the various domains in life [...].

Validity and feasibility of an obstacle course to assess fundamental movement skills in a pre-school setting.

Failure to master age-appropriate fundamental movement skills (FMS) at a young age can limit motor skill competence affecting health. Assessments often have issues with feasibility and implementation in a field setting. As such, the purpose of this study was to investigate the validity and feasibility of the Athletic Skills Track (AST), in a pre-school setting. For the validation study sixty-five 3-6 year old children (25 boys and 40 girls) from five pre-schools across Adelaide, Australia participated. Correlations and linear regression analysis (adjusted for age and gender) were used to investigate the association between the time to complete the AST and the raw score of the Test of Gross Motor Development 2 (TGMD-2). For the feasibility study pre-school staff completed a semi-structured interview regarding the feasibility of the AST. The AST took less than a minute per child and the TGMD-2 around 20 minutes for two children. There was a strong negative correlation (r = -0.63, p < 0.01) between the AST scores and the TGMD-2 scores. All five staff reported strengths of the AST to be its short administration time, setup and appropriateness. These results suggest that the AST could be a feasible and valid method of FMS assessment in Australian pre-schools.

A Multicomponent Schoolyard Intervention Targeting Children's Recess Physical Activity and Sedentary Behavior: Effects After 1 Year.

BACKGROUND: The aim of the study was to test the 12-month effects of a multicomponent physical activity (PA) intervention at schoolyards on morning recess PA levels of sixth- and seventh-grade children in primary schools, using accelerometry and additional global positioning system data. METHODS: A quasi-experimental study design was used with 20 paired intervention and control schools. Global positioning system confirmatory analyses were applied to validate attendance at schoolyards during recess. Accelerometer data from 376 children from 7 pairs of schools were included in the final analyses. Pooled intervention effectiveness was tested by multilevel linear regression analyses, whereas effectiveness of intervention components was tested by multivariate linear regression analyses. RESULTS: Children exposed to the multicomponent intervention increased their time spent in light PA (+5.9%) during recess. No pooled effects on moderate to vigorous PA were found. In-depth analyses of intervention components showed that physical schoolyard interventions particularly predicted a decrease in time spent in sedentary behavior during recess at follow-up. Intervention intensity and the school's commitment to the project strengthened this effect. CONCLUSIONS: The multicomponent schoolyard PA intervention was effective in making children spend a larger proportion of recess time in light PA, which was most likely the result of a shift from sedentary behavior to light PA.

Schoolyard Characteristics, Physical Activity, and Sedentary Behavior: Combining GPS and Accelerometry.

BACKGROUND: Physical activity (PA) is decreasing among children, while sedentary behavior (SB) is increasing. Schoolyards seem suitable settings to influence children's PA behavior. This study investigated the associations between schoolyard characteristics and moderate-to-vigorous physical activity (MVPA) and SB of children aged 8-11 years at schoolyards. METHODS: Twenty primary schools in the Netherlands were involved. A total of 257 children wore an accelerometer and global positioning system (GPS) device for 5 consecutive days to objectively assess their PA levels and presence at the schoolyard, respectively. Accelerometer and GPS data were merged using the personal activity and location measurement system. Multilevel linear regression analyses were used to study correlates of MVPA and SB at schoolyards. RESULTS: On average, children spent 54 minutes a day at the schoolyard, 9 minutes of which were spent in MVPA and 20 minutes in SB. Boys engaged in MVPA longer than girls at the schoolyard. Fixed equipment, such as high bars and soccer goals, teacher-initiated activities, and the presence of a ball games policy were correlates of more MVPA and less SB. CONCLUSION: Well-designed schoolyards, including PA-enhancing fixed equipment, a supportive PA climate created by teachers, and supportive schoolyard policies may contribute to increased PA and decreased SB during school recess among school-aged children.

Children's route choice during active transportation to school: difference between shortest and actual route.

BACKGROUND: The purpose of this study is to increase our understanding of environmental correlates that are associated with route choice during active transportation to school (ATS) by comparing characteristics of actual walking and cycling routes between home and school with the shortest possible route to school. METHODS: Children (n = 184; 86 boys, 98 girls; age range: 8-12 years) from seven schools in suburban municipalities in the Netherlands participated in the study. Actual walking and cycling routes to school were measured with a GPS-device that children wore during an entire school week. Measurements were conducted in the period April-June 2014. Route characteristics for both actual and shortest routes between home and school were determined for a buffer of 25 m from the routes and divided into four categories: Land use (residential, commercial, recreational, traffic areas), Aesthetics (presence of greenery/natural water ways along route), Traffic (safety measures such as traffic lights, zebra crossings, speed bumps) and Type of street (pedestrian, cycling, residential streets, arterial roads). Comparison of characteristics of shortest and actual routes was performed with conditional logistic regression models. RESULTS: Median distance of the actual walking routes was 390.1 m, whereas median distance of actual cycling routes was 673.9 m. Actual walking and cycling routes were not significantly longer than the shortest possible routes. Children mainly traveled through residential areas on their way to school (>80% of the route). Traffic lights were found to be positively associated with route choice during ATS. Zebra crossings were less often present along the actual routes (walking: OR = 0.17, 95% CI = 0.05-0.58; cycling: OR = 0.31, 95% CI = 0.14-0.67), and streets with a high occurrence of accidents were less often used during cycling to school (OR = 0.57, 95% CI = 0.43-0.76). Moreover, percentage of visible surface water along the actual route was higher compared to the shortest routes (walking: OR = 1.04, 95% CI = 1.01-1.07; cycling: OR = 1.03, 95% CI = 1.01-1.05). DISCUSSION: This study showed a novel approach to examine built environmental exposure during active transport to school. Most of the results of the study suggest that children avoid to walk or cycle along busy roads on their way to school.

Longitudinal association of neighborhood variables with Body Mass Index in Dutch school-age children: The KOALA Birth Cohort Study.

Changes in the neighborhood environment may explain part of the rapid increase in childhood overweight and obesity during the last decades. To date few theory-driven rather than data-driven studies have explored longitudinal associations between multiple neighborhood characteristics and child body weight development. We aimed to assess the relationship between physical, social and perceived safety related characteristics of the neighborhood and Body Mass Index (BMI) development in children during early school age, using a longitudinal design. We included an examination of moderating and confounding factors based on a conceptual model adapted from the EnRG framework (Environmental Research framework for weight Gain prevention) and empirical research. Analyses included 1887 children from the KOALA Birth Cohort Study followed from baseline age 4-5 years until 8-9 years. For children age 4-5 years, parents completed a questionnaire measuring characteristics of the neighborhood. Reliability and factor analyses were used to identify constructs for neighborhood characteristics. Linear regression analysis was performed to assess the relationship between neighborhood constructs and BMI z-scores cross-sectionally at age 4-5 years and longitudinally using Generalized Estimating Equations with BMI z-scores over 5 repeated measurements until age 8-9 years. Fourteen constructs were identified and grouped in three domains including perceived physical, social, or safety related characteristics of the neighborhood. Cross-sectionally, a lower BMI z-score was associated with higher perceived physical attractiveness of the neighborhood environment (standardized regression coefficient (ß) -0.078, 95% CI -0.123 to -0.034) and a higher level of social capital (ß -0.142, -0.264 to -0.019). Longitudinally, similar associations were observed with potentially even stronger regression coefficients. This study suggests that BMI in children is mainly related to the modifiable physical and social environment of the conceptual model and not related to safety as perceived by parents.

Physical activity in non-frail and frail older adults.

INTRODUCTION: Physical activity (PA) is important for healthy ageing. Better insight into objectively measured PA levels in older adults is needed, since most previous studies employed self-report measures for PA assessment, which are associated with overestimation of PA. AIM: This study aimed to provide insight in objectively measured indoor and outdoor PA of older adults, and in PA differences by frailty levels. METHODS: Data were collected among non-frail (N = 74) and frail (N = 10) subjects, aged 65 to 89 years. PA, measured for seven days with accelerometers and GPS-devices, was categorized into three levels of intensity (sedentary, light, and moderate-to-vigorous PA). RESULTS: Older adults spent most time in sedentary and light PA. Subjects spent 84.7%, 15.1% and 0.2% per day in sedentary, light and moderate-to-vigorous PA respectively. On average, older adults spent 9.8 (SD 23.7) minutes per week in moderate-to-vigorous activity, and 747.0 (SD 389.6) minutes per week in light activity. None of the subjects met the WHO recommendations of 150 weekly minutes of moderate-to-vigorous PA. Age-, sex- and health status-adjusted results revealed no differences in PA between non-frail and frail older adults. Subjects spent significantly more sedentary time at home, than not at home. Non-frail subjects spent significantly more time not at home during moderate-to-vigorous activities, than at home. CONCLUSIONS: Objective assessment of PA in older adults revealed that most PA was of light intensity, and time spent in moderate-to-vigorous PA was very low. None of the older adults met the World Health Organization recommendations for PA. These levels of MVPA are much lower than generally reported based on self-reported PA. Future studies should employ objective methods, and age specific thresholds for healthy PA levels in older adults are needed. These results emphasize the need for effective strategies for healthy PA levels for the growing proportion of older adults.

The value of (pre)school playgrounds for children's physical activity level: a systematic review.

The (pre)school environment is an important setting to improve children's health. Especially, the (pre)school playground provides a major opportunity to intervene. This review presents an overview of the existing evidence on the value of both school and preschool playgrounds on children's health in terms of physical activity, cognitive and social outcomes. In addition, we aimed to identify which playground characteristics are the strongest correlates of beneficial effects and for which subgroups of children effects are most distinct. In total, 13 experimental and 17 observational studies have been summarized of which 10 (77%) and 16 (94%) demonstrated moderate to high methodological quality, respectively. Nearly all experimental studies (n = 11) evaluated intervention effects on time spent in different levels of physical activity during recess. Research on the effects of (pre)school playgrounds on cognitive and social outcomes is scarce (n = 2). The experimental studies generated moderate evidence for an effect of the provision of play equipment, inconclusive evidence for an effect of the use of playground markings, allocating play space and for multi-component interventions, and no evidence for an effect of decreasing playground density, the promotion of physical activity by staff and increasing recess duration on children's health. In line with this, observational studies showed positive associations between play equipment and children's physical activity level. In contrast to experimental studies, significant associations were also found between children's physical activity and a decreased playground density and increased recess duration. To confirm the findings of this review, researchers are advised to conduct more experimental studies with a randomized controlled design and to incorporate the assessment of implementation strategies and process evaluations to reveal which intervention strategies and playground characteristics are most effective.

Active transport between home and school assessed with GPS: a cross-sectional study among Dutch elementary school children.

BACKGROUND: Active transport to school is associated with higher levels of physical activity in children. Promotion of active transport has therefore gained attention as a potential target to increase children's physical activity levels. Recent studies have recognized that the distance between home and school is an important predictor for active travel among children. These studies did not yet use the promising global positioning system (GPS) methods to objectively assess active transport. This study aims to explore active transport to school in relation to the distance between home and school among a sample of Dutch elementary school children, using GPS. METHODS: Seventy-nine children, aged 6-11 years, were recruited in six schools that were located in five cities in the Netherlands. All children were asked to wear a GPS receiver for one week. All measurements were conducted between December 2008 and April 2009. Based on GPS recordings, the distance of the trips between home and school were calculated. In addition, the mode of transport (i.e., walking, cycling, motorized transport) was determined using the average and maximum speed of the GPS tracks. Then, proportion of walking and cycling trips to school was determined in relation to the distance between home and school. RESULTS: Out of all school trips that were recorded (n=812), 79.2% were classified as active transport. On average, active commuting trips were of a distance of 422 meters with an average speed of 5.2 km/hour. The proportion of walking trips declined significantly at increased school trip distance, whereas the proportion of cycling trips (ß=1.23, p<0.01) and motorized transport (ß=3.61, p<0.01) increased. Almost all GPS tracks less than 300 meters were actively commuted, while of the tracks above 900 meters, more than half was passively commuted. CONCLUSIONS: In the current research setting, active transport between home and school was the most frequently used mode of travel. Increasing distance seems to be associated with higher levels of passive transport. These results are relevant for those involved in decisions on where to site schools and residences, as it may affect healthy behavior among children.

Relationship between physical activity and the development of body mass index in children.

PURPOSE: Studies estimating the contribution of physical activity (PA) to the development of body mass index (BMI) in critical periods of childhood are warranted. Therefore, we have prospectively investigated this relationship in boys and girls of the KOALA Birth Cohort study, the Netherlands, in the period around adiposity rebound (i.e., 4-9 yr old). METHODS: PA was assessed in 470 children (231 boys, 239 girls) using accelerometers at the ages of 5 and 7 yr, and height and weight were measured at 5, 7, and 9 yr. BMI z-scores were calculated to standardize for age and sex. Leaner and heavier children were classified according to the 25th and 75th percentile of our study sample. To examine longitudinal relationships between PA and BMI z-scores, generalized estimating equation analyses were performed and stratified for sex and baseline weight status (leaner, normal weight, and heavier children). RESULTS: In heavier children, an increment of 6.5 min of moderate to vigorous PA (MVPA) was related to a subsequent decrease of 0.03 BMI z-scores both in boys (95% confidence interval = -0.07 to -0.001) and girls (95% confidence interval = -0.05 to -0.002). Light PA was also associated with a decrease of BMI in heavier boys but not girls. In normal weight children, MVPA was associated with decrease of BMI in boys but not girls. CONCLUSION: Increments of MVPA were associated with decreases in BMI z-score in heavier children, both boys and girls. Promoting MVPA should remain a major prevention vehicle for improving body composition in 4- to 9-yr-old children.

Schoolyard physical activity of 6-11 year old children assessed by GPS and accelerometry.

BACKGROUND: Children's current physical activity levels are disturbingly low when compared to recommended levels. This may be changed by intervening in the school environment. However, at present, it is unclear to what extent schoolyard physical activity contributes towards reaching the daily physical activity guideline. The aim of this study was to examine how long and at what intensity children are physically active at the schoolyard during different time segments of the day. Moreover, the contribution of schoolyard physical activity towards achieving the recommended guideline for daily physical activity was investigated. METHODS: Children (n=76) between the age of 6-11 years were recruited in six different schools in five cities (>70.000 residents) in the Netherlands. During the weekdays of a regular school week, childrens' physical activity and location were measured with ActiGraph accelerometers and Travelrecorder GPS receivers. Data was collected from December 2008 to April 2009. From the data, the amount of moderate to vigorous physical activity (MVPA) on and outside the schoolyard was established. Moreover, the percentage of MVPA on the schoolyard was compared between the following segments of the day: pre-school, school, school recess, lunch break and post-school. Differences between boys and girls were compared using linear and logistic mixed-effects models. RESULTS: On average, children spent 40.1 minutes/day on the schoolyard. During this time, boys were more active on the schoolyard, with 27.3% of their time spent as MVPA compared to 16.7% among girls (OR=2.11 [95% CI 1.54 - 2.90]). The children were most active on the schoolyard during school recess, during which boys recorded 39.5% and girls recorded 23.4% of the time as MVPA (OR=2.55 [95% CI: 1.69 - 3.85]). Although children were only present at the schoolyard for 6.1% of the total reported time, this time contributed towards 17.5% and 16.8% of boys' and girls' minutes of MVPA. CONCLUSIONS: On the schoolyard, children's physical activity levels are higher than on average over the whole day. Physical activity levels are particularly high during school recess. The school environment seems to be an important setting for improving children's physical activity levels. Further research on the facilitators of these high activity levels may provide targets for further promotion of physical activity among children.

Preschool physical activity and functional constipation: the Generation R study.

OBJECTIVES: Decreased physical activity levels in children may partly explain the rising prevalence of functional constipation in childhood. The aim of the present study, therefore, was to examine the association between physical activity and functional constipation during the preschool period. METHODS: This study was embedded in the Generation R study, a large prospective birth-cohort study in Rotterdam, The Netherlands. Physical activity was measured by an Actigraph accelerometer in 347 children (182 boys, 165 girls; mean age 25.1 months) and data were expressed as counts per minute. Data were categorized into light activity (302-614 counts/15 seconds), moderate activity (615-1230 counts/15 seconds), and vigorous activity (≥1231 counts/15 seconds). Functional constipation in the third and fourth year of life was defined according to the Rome II criteria. RESULTS: Children spending time in the highest tertile of light (adjusted odds ratio [OR] 0.34; 95% confidence interval [CI] 0.13-0.87), moderate (adjusted OR 0.37; 95% CI 0.14-0.97), and total activity (adjusted OR 0.37; 95% CI 0.15-0.92) at the age of 2 years had significantly less functional constipation in the fourth year of life. For functional constipation in the third year of life, the results were in similar direction but not statistically significant. Additionally, children with physical activity of more than the WHO recommendation of 60 min/day had significantly less functional constipation in the fourth year of life (adjusted OR 0.48; 95% CI 0.24-0.97). CONCLUSIONS: Physical activity is associated with a decreased risk of functional constipation in the preschool period, but this may be time dependent.

The Steep Ramp Test in Dutch white children and adolescents: age- and sex-related normative values.

BACKGROUND: The Steep Ramp Test (SRT), a feasible, reliable, and valid exercise test on a cycle ergometer, may be more appealing for use in children in daily clinical practice than the traditional cardiopulmonary exercise test because of its short duration, its resemblance to children's daily activity patterns, and the fact that it does not require respiratory gas analysis. OBJECTIVE: The aim of the present study was to provide sex- and age-related normative values for SRT performance in Dutch white children and adolescents who were healthy and 8 to 19 years old. DESIGN: This was a cross-sectional, observational study. METHODS: A total of 252 Dutch white children and adolescents, 118 boys (mean age=13.4 years, SD=3.0) and 134 girls (mean age=13.4 years, SD=2.9), performed the SRT (work rate increment of 10, 15, or 20 W·10 s(-1), depending on body height) to voluntary exhaustion to assess peak work rate (WRpeak). Normative values are presented as reference centiles developed by use of generalized additive models for location, scale, and shape. RESULTS: Peak work rate correlated highly with age (r=.915 and r=.811), body mass (r=.870 and r=.850), body height (r=.922 and r=.896), body surface area (r=.906 and r=.885), and fat free mass (r=.930 and r=.902) in boys and girls, respectively. The reference curves demonstrated an almost linear increase in WRpeak with age in boys, even when WRpeak was normalized for body mass. In contrast, absolute WRpeak in girls increased constantly until the age of approximately 13 years, when it started to level off. Peak work rate normalized for body mass in girls showed only a slight increase with age until 14 years of age, when a slight decrease in relative WRpeak was observed. LIMITATIONS: The sample may not have been entirely representative of the Dutch population. CONCLUSIONS: The present study provides sex- and age-related normative values for SRT performance in terms of both absolute WRpeak and relative WRpeak, thereby facilitating the interpretation of SRT results by clinicians and researchers.

Correlates of physical activity in 2-year-old toddlers: the generation R study.

OBJECTIVE: To describe and identify correlates of objectively measured physical activity and sedentary behavior in 2-year-old toddlers. STUDY DESIGN: A total of 347 children participating in a birth cohort study wore a unaxial ActiGraph accelerometer during 1 weekday and 1 weekend day. Information on potential correlates was assessed by parent-reported questionnaires, delivery reports, and regular visits to child health centers. Univariate and multivariable linear regression analyses were conducted to examine the associations between potential correlates and the following physical activity outcomes: percentage of time spent in sedentary behavior, percentage of time spent in moderate-to-vigorous physical activity, and mean counts per minute. RESULTS: A high percentage of monitored time was spent in sedentary behavior; 85.6% on weekdays and 84.5% on weekend days. Four correlates were significantly associated with at least 1 physical activity outcome in the multivariable regression models: child's sex, child's age, number of siblings, and season of measurement. The associations of gross motor development with moderate-to-vigorous physical activity and mean counts per minute approached significance. Associations of socioeconomic variables and child's body mass index z-score with physical activity outcomes were not significant. CONCLUSION: Two-year-old toddlers spend most of their time in sedentary behavior. No modifiable correlates were identified. Further research on physical activity and associated health benefits among very young children is warranted.

The steep ramp test in healthy children and adolescents: reliability and validity.

PURPOSE: This study aimed to examine the reliability and validity of the steep ramp test (SRT), a feasible, maximal exercise test on a cycle ergometer that does not require the use of respiratory gas analysis, in healthy children and adolescents. METHODS: Seventy-five children were randomly divided in a reliability group (n = 37, 17 boys and 20 girls; mean ± SD age = 13.86 ± 3.22 yr), which performed two SRTs within 2 wk, and a validity group (n = 38, 17 boys and 21 girls; mean ± SD age = 13.85 ± 3.20 yr), which performed both an SRT and a regular cardiopulmonary exercise test (CPET) with respiratory gas analysis within 2 wk. Peak work rate (WRpeak) was the main outcome of the SRT. Peak oxygen uptake (VO2peak) was the main outcome of the CPET. Reliability was examined with the intraclass correlation coefficient and a Bland and Altman plot, whereas validity was assessed using Pearson correlation coefficients and stepwise linear regression analysis. RESULTS: Reliability statistics for the WRpeak values attained at the two SRTs showed an intraclass correlation coefficient of 0.986 (P < 0.001). The average difference between the two SRTs was -6.4 W, with limits of agreement between +24.5 and -37.5 W. A high correlation between WRpeak attained at the SRT and the V˙O2peak achieved during the CPET was found (r = 0.958; P < 0.001). Stepwise linear regression analysis provided the following prediction equation: VO2peak (mL·min) = (8.262 WRpeak SRT) + 177.096 (R2 = 0.917, SEE = 237.4). CONCLUSION: The results suggest that the SRT is a reliable and valid exercise test in healthy children and adolescents, which can be used to predict VO2peak.

Outdoor play among children in relation to neighborhood characteristics: a cross-sectional neighborhood observation study.

BACKGROUND: Although environmental characteristics as perceived by parents are known to be related to children's outdoor play behavior, less is known about the relation between independently measured neighborhood characteristics and outdoor play among children. The purpose of this study was to identify quantitative as well as qualitative neighborhood characteristics related to outdoor play by means of neighborhood observations. METHODS: Questionnaires including questions on outdoor play behavior of the child were distributed among 3,651 parents of primary school children (aged 4-12 years). Furthermore, neighborhood observations were conducted in 33 Dutch neighborhoods to map neighborhood characteristics such as buildings, formal outdoor play facilities, public space, street pattern, traffic safety, social neighborhood characteristics, and general impression. Data of the questionnaires and the neighborhood observations were coupled via postal code of the respondents. Multilevel GEE analyses were performed to quantify the correlation between outdoor play and independently measured neighborhood characteristics. RESULTS: Parental education was negatively associated with outdoor play among children. Neither the presence nor the overall quality of formal outdoor play facilities were (positively) related to outdoor play among children in this study. Rather, informal play areas such as the presence of sidewalks were related to children's outdoor play. Also, traffic safety was an important characteristic associated with outdoor play. CONCLUSIONS: This study showed that, apart from individual factors such as parental education level, certain modifiable characteristics in the neighborhood environment (as measured by neighborhood observations) were associated with outdoor play among boys and girls of different age groups in The Netherlands. Local policy makers from different sectors can use these research findings in creating more activity-friendly neighborhoods for children.