Eveline Van Cauwenberghe

The contribution of preschool playground factors in explaining children's physical activity during recess

BackgroundLow levels of physical activity are characteristic in preschoolers. To effectively promote physical activity, it is necessary to understand factors that influence young childrens physical activity. The present study aimed to investigate how physical activity levels are influenced by environmental factors during recess in preschool.MethodsPreschool playground observations and pedometry during recess were carried out in 39 randomly selected preschools (415 boys and 368 girls; 5.3 ± 0.4 years old). In order to examine the contribution of playground variables to physical activity levels, taking adjustment for clustering of subjects within preschools into account, multilevel analyses were conducted.ResultsDuring recess boys took significantly more steps per minute than girls (65 ± 36 versus 54 ± 28 steps/min). In both genders higher step counts per minute were significantly associated with less children per m2 and with shorter recess times. Only in boys a hard playground surface was a borderline significant predictor for higher physical activity levels. In girls higher step counts were associated with the presence of less supervising teachers. Playground markings, access to toys, the number of playing or aiming equipment pieces and the presence of vegetation or height differences were not significant physical activity predictors in both genders.ConclusionIn preschool children physical activity during outdoor play is associated with modifiable playground factors. Further study is recommended to evaluate if the provision of more play space, the promotion of continued activity by supervisors and the modification of playground characteristics can increase physical activity levels in preschoolers.

Objectively measured sedentary time and physical activity time across the lifespan: a cross-sectional study in four age groups

BackgroundFrom a health perspective it is suggested to promote a positive balance between time spent in light intensity physical activity (LIPA) and sedentary behaviour (SB) (i.e. spending more time in LIPA than time spent in SB). However, no studies have reported prevalence rates of the LIPA-SB balance yet. The aim of this study was to objectively investigate the time spent in SB, in LIPA and moderate-to-vigorous intensity physical activity (MVPA) in four Belgian age groups and to explore which proportion of the population had a favorable balance between LIPA and SB and combined this with recommended amount of MVPA.MethodsAccelerometer data from 7 cross-sectional studies (N=2083) in four age groups (preschoolers, primary schoolchildren, secondary schoolchildren and adults) were aggregated. Differences in SB and PA between age groups and between men and women were determined by two-way MANCOVA. LIPA-SB balance was calculated and participants were categorized into one of four groups: (1) positive LIPA-SB balance (LIPA> SB) & sufficient MVPA (2) negative LIPA-SB balance & sufficient MVPA (3) positive LIPA-SB balance & insufficient MVPA (4) negative LIPA-SB balance & insufficient MVPA.ResultsFor the total sample, 55% of the waking time was spent in SB, 39% in LIPA and 6% in MVPA. Differences in SB between age groups was dependent from gender (p<0.001). Further, a positive LIPA-SB balance was assessed in 18% of the total sample and only 10% combined this positive balance with recommended amount of MVPA. Secondary schoolgirls were most at risk, with only 1% of the sample combining a positive LIPA-SB balance with sufficient MVPA. Another risk group was the large proportion (43%) of adult men who combined sufficient MVPA with a negative LIPA-SB balance.ConclusionA high proportion of the Belgian population is at risk if taking into account both SB and PA levels. Secondary schoolgirls have the unhealthiest SB and PA profile and are therefore an important target group for interventions both increasing MVPA and decreasing SB. In men more attention should be given in promoting a positive LIPA-SB balance independently from their compliance with the MVPA guidelines.

Worksite Physical Activity Interventions and Obesity: A Review of European Studies (the HOPE Project)

Objective: Our aim was to review the effectiveness of physical activity promotion interventions in the worksite setting in Europe in order to identify those studies that had measured obesity-related outcomes and to evaluate how external validity of the findings had been assessed. Methods: We conducted a review of studies conducted in Europe, published up to December 2009. We assessed levels of evidence regarding effectiveness and analysed external validity using the RE-AIM framework. Results: Studies included (n = 33) were divided in 6 intervention categories. Moderate evidence of effectiveness was found for physical fitness outcomes with exercise training interventions and for physical activity outcomes with active commuting interventions. There was no or inconclusive evidence for obesity-related outcomes for all intervention categories. For external validity, elements receiving the least attention (<20%) were representativeness of participants, setting-level inclusion/exclusion criteria and representativeness, characteristics regarding intervention staff, implementation of intervention, costs, long-term effects and programme sustainability. Conclusions: Active commuting and exercise training appear as promising approaches to promote physical activity or fitness in the workplace. The effect of interventions on obesity-related outcomes remains to be further investigated. There is a need to better report elements of generalizability and dissemination for translation into practice of worksite physical activity interventions.

Validity of the ActivPAL™ and the ActiGraph monitors in preschoolers

PURPOSE This study aimed to compare three objective measures (GT1M ActiGraph, ActivPAL™, and direct observation) of sedentary behavior in preschoolers. METHODS Fifty-two 4- to 6-yr-old preschoolers wore an ActivPAL™ and a GT1M ActiGraph for five consecutive days and were videotaped for 1 h during classroom activities at preschool. The area under the receiver operating characteristic curve was calculated to assess the criterion validity of the ActivPAL™ (sitting/lying, with and without standing still) and the GT1M ActiGraph (<100 counts per minute) to estimate sedentary behavior (directly observed sitting behaviors). A two-way repeated-measures ANOVA was used to define the convergent validity of the ActivPAL™ and the GT1M ActiGraph sedentary behavior estimates across the measurement days. The practical utility of the ActivPAL™ was tested in the same sample by asking the parents how their child perceived wearing the ActivPAL™. RESULTS Results indicated a poor classification accuracy for both devices (area under the receiver operating characteristic curve, 0.6) to measure sedentary behavior based on the direct observation, with and without the inclusion of standing. Time defined as sedentary behavior (sitting/lying) was lower for the ActivPAL™ compared with the GT1M ActiGraph (mean bias, 7.7%; limits of agreement, -29.01% to 13.6%). According to the parental reports, 38% of the preschoolers had skin irritation due to wearing the ActivPAL™ for consecutive days. CONCLUSIONS Low classification accuracy was found for the ActivPAL™ and the GT1M ActiGraph to measure sedentary behavior in preschoolers. No correction factor can be suggested to make the sedentary estimates of the GT1M ActiGraph and the ActivPAL™ convergent as no systematic bias and wide limits of agreement were found. Furthermore, the practical utility of the ActivPAL™ was perceived to be lower compared with the ActiGraph accelerometer in preschoolers.

Comparison of Actical and activPAL measures of sedentary behaviour in preschool children.

OBJECTIVES The purpose of this study was to examine the convergent validity of the Actical and activPAL to measure sedentary behaviour (SB) and non-SB in preschoolers in a free-living environment. DESIGN A convenience sample of 49 preschoolers (22 boys; 4.0 ± 0.5 years) from six early childhood centres in Auckland, New Zealand were included in data analysis. METHODS Participants wore a hip-mounted Actical and a thigh-mounted activPAL accelerometer simultaneously during centre attendance for one day and data were collected in 15s epochs. Bland-Altman tests were used to assess differences in group mean minutes and percentage of time in (non-)SB between both monitors. Agreement between binary coded (SB vs. non-SB) 15s-by-15s Actical and activPAL data was evaluated by calculating percentage agreement and κ statistic. RESULTS The monitors were worn on average for 294.8 ± 46.3 min resulting in a total of 57,780 15s epochs. Bland-Altman tests suggested a small group mean difference in (non-)SB (1.3 min; 0.1%) and a wide prediction interval (121.3 min; 39.2%). No obvious systematic bias was observed in the Bland-Altman plot. Percentage agreement between the 15s-by-15s Actical and activPAL data of all participants was 73.0% (inter-child range: 36.8-93.8%). The κ statistic showed moderate agreement with a value of 0.46 (95% CI: 0.45-0.47). CONCLUSIONS Although the group mean estimate of (non-)SB was similar between the Actical and activPAL, the output of both monitors cannot be considered convergent as meaningful random disagreement was found between both monitors.

Patterns of physical activity in preschool aged children

Poster presentations International Journal of Obesity (2011) 35, S151–S168; doi:10.1038/ijo.2011.49