Intervention Effects of the Health Promotion Programme "Join the Healthy Boat" on Objectively Assessed Sedentary Time in Primary School Children in Germany.

Sedentary behaviour (SB) in children is related to negative health consequences that can track into adulthood. The programme "Join the Healthy Boat" promotes reduced screen time and a less sedentary lifestyle in schoolchildren. This study investigated the effects of the programme on children's SB. For one year, teachers delivered the programme. A total of 231 children (7.0 ± 0.6 years) participated in the cluster-randomised study; there were 154 one year later at follow-up. Children's SB was assessed using multi-sensor accelerometery, screen time via parental questionnaire. Effects were analysed using (linear) mixed effects regression models. At baseline, children spent 211 (±89) min daily in SB, at follow-up 259 (±109) min/day with no significant difference between the intervention (IG) and control group (CG). SB was higher during weekends (p < 0.01, for CG and IG). However, at follow-up, daily screen time decreased in IG (screen time of >1 h/day: baseline: 33.3% vs. 27.4%; follow-up: 41.2% vs. 27.5%, for CG and IG, respectively). This multi-dimensional, low-threshold intervention for one year does not seem to achieve a significant reduction in children's SB, although screen time decreased in IG. Therefore, it should be considered that screen time cannot be the key contributor to SB and should not solely be used for changing children's SB. However, if screen time is targeted, interventions should promote the replacement of screen time with active alternatives.

High sedentary time in children is not only due to screen media use: a cross-sectional study.

BACKGROUND: Sedentary behaviour has become a growing public health concern. Currently, it is a common belief that screen time (SCT) is a key factor in high overall sedentary time (ST) and is often used as a primary outcome. However, the evidence is lacking. Therefore, this study investigated the association of objectively assessed total ST with SCT among children. Further, SCT was investigated separately for sedentary level, weight status, gender, and migration background. METHODS: For 198 primary school children (7.1 ± 0.7 years, boys: 43.9%) ST was assessed objectively using a multi-sensor device (Actiheart®; CamNtech, Cambridge, UK). The sample was split into three groups (tertiles) to investigate SCT of children with low, medium and high ST. SCT and socio-demographic parameters, such as migration background, were assessed using a parental questionnaire; anthropometric data was collected at schools. RESULTS: Absolut SCT did not differ significantly among the three sedentary groups: Daily average of SCT was 83.8 ± 55.0 min (27.4% of ST) for children with high ST, 82.8 ± 50.5 min (39.8% of ST) for children with medium ST, and 77.2 ± 59.4 min (71.3% of ST) for those with low ST. However, relatively the SCT percentage of total ST was significantly higher among children with low ST (p < 0.01). Significantly higher SCT was found in children with migration background (p < 0.01), while underweight children had significantly less SCT (p < 0.05). An association of total SCT and overall ST was found for the whole sample (B = 17.11, [2.75; 31.48], p = 0.02), but did not remain when analysis were separated for the groups, except for normal weight children (B = 15.97, [0.13; 31.81], p = 0.05). CONCLUSIONS: The amount of SCT is the same among high, low and medium sedentary children, and high ST is largely independent of SCT. Therefore, SCT cannot be the key contributor to high ST and should not solely be used for predicting or changing children's sedentary behaviour. Moreover, children's weight status to classify activity levels and the role of possible compensation mechanisms should be considered in future research and when trying to intervene on ST. TRIAL REGISTRATION: German Clinical Trials Register (DRKS), DRKS-ID: DRKS00000494 DATE: 25/08/2010.

Cross-sectional associations of objectively assessed sleep duration with physical activity, BMI and television viewing in German primary school children.

BACKGROUND: The global incidence of overweight and obesity has increased dramatically among children and adolescents over the past decades. Insufficient sleep duration and physical inactivity are known risk factors for overweight and obesity in children. To engage children in a healthier lifestyle knowledge about associations of sleep duration and behavioural aspects in children are vital. Therefore, this study investigated the mentioned associations in German primary school children. METHODS: Data of 308 first and second graders (7.1 ± 0.6 years) was used; children's anthropometric data were taken during a school visit. Children's physical activity (PA) and sleep duration were assessed objectively (Actiheart©, CamNtech Ltd., Cambridge, UK); children's daily television time and socio-demographic data were collected via parental questionnaire. Linear mixed-effects regression models as well as logistic regressions were used to determine associations of PA, television viewing, age, gender, BMI z-scores and socio-economic variables on sleep duration. RESULTS: In linear regression models young age and not having a migration background were significantly associated with long sleep duration (p < 0.001). In logistic regressions, long night time sleep (≥10:08 h; compared to medium and short sleep duration) was significantly associated with not reaching the PA guideline (OR 0.60 [0.36;0.99]), daily television viewing of less than one hour (OR 0.44 [0.24;0.80]), young age (OR 0.38 [0.21;067]), a high parental education level (OR 0.52 [0.27;0.99]) and the lack of migration background (OR 0.21 [0.10;0.48]). However, if controlling for age, gender, parental education level and migration background, reaching the PA guideline stayed no longer significantly associated with a tertiary sleep level. CONCLUSIONS: Children in the highest sleep category showed a negative association with reaching the PA guideline and a positive association with daily television viewing. This therefore adds to previously primarily subjectively assessed associations of sleep and risk factors for obesity (related behaviours) with a detailed insight based on objective data. Hence, interventions trying to decrease children's BMI and television viewing should also aim at extending children's night-time sleep and inform parents about the importance of sufficient sleep during childhood. TRIAL REGISTRATION: DRKS-ID: DRKS00000494 .

Sedentary time among primary school children in south-west Germany: amounts and correlates.

BACKGROUND: Sedentary behaviour in children is related to different health consequences such as overweight and cardio-metabolic diseases that can track into adulthood. Previous studies have shown that children spend hours being sedentary, but no data of sedentary time (ST) among German children has been available, yet. Therefore, this study investigated objectively measured amounts and correlates of ST in a sample of German primary school children. METHODS: Children's physical activity (PA) was objectively assessed for 6 days using a multi-sensor device (Actiheart®; CamNtech, Cambridge, UK). Activity levels were categorized on the basis of energy expenditure (MET) into sedentary, light PA (LPA), and moderate to vigorous PA (MVPA). ST excluding sleeping hours was assessed for 231 children (7.1 ± 0.6 years, male: 45.9%) and analysed for independent groups. Examined factors (parental education, household income, and migration background) were assessed by parental questionnaire. Children's weight, height and gender were collected in schools. Weight status was calculated on the basis of BMI percentiles. RESULTS: On average, children spent 3.5 ± 1.5 h daily being sedentary, excluding sleeping hours. Significantly higher ST was found in girls (t = -4.6; p < 0.01), in children with migration background (t = -6.9; p < 0.01), at the weekend (t = -2.8; p < 0.01), and among inactive children (t = 6.8; p < 0.01). Additionally, significant correlations with ST in this sample were identified for MVPA (B = -0.99; [-1.09;-0.88], p < 0.01), LPA (B = -0.89; [-0.97;-0.82], p < 0.01), migration background (B = -17.64; [5.24;30.04], p < 0.01), gender (B = -13.48; [-25.94;-1.01], p < 0.05) and household income (B = -4.80; [-9.07; -0.53], p < 0.05). CONCLUSION: Girls, children with migration background, and inactive children were identified as potential risk groups. A higher income was associated with less ST. In general, ST was higher at the weekend. Furthermore, as PA was found to be negatively correlated to ST, these activities may replace each other. Therefore, these findings should be considered in future health interventions. TRIAL REGISTRATION: German Clinical Trials Register (DRKS), DRKS-ID: DRKS00000494 DATE: 25/08/2010.

Physical activity of German children during different segments of the school day.

AIM: This study objectively investigated the amount and intensity of German primary school children's physical activity (PA) during different segments of the school day and explored the contribution of physical education (PE) and break times to daily moderate to vigorous PA (MVPA). SUBJECT AND METHODS: PA of 294 children (7.1 ± 0.7 years, 48 % male) was objectively measured for 6 days using Actiheart®. Based on children's timetables, break times and PE periods were determined and PA was calculated individually and subsequently classified in light (1.5-3 MET), moderate (3-6 MET) and vigorous (>6 MET) intensities. Weight status was determined during a school visit. RESULTS: Children spent 133 ± 61 min in MVPA; on weekdays, this amount increased significantly (141 ± 66 min, p ≤ 0.01). 45.9 % of children reached physical activity guidelines of 60 min of MVPA daily, with boys achieving this goal significantly more often than girls (65.6 vs. 28.7 %, respectively; p ≤ 0.01). PE lessons and break times accounted for 15 ± 13 min (12.7 %) and 7 ± 6 min (5.8 %) of daily MVPA, respectively. On days with PE, children spent 144 ± 68 min in MVPA, whereas on days without PE, this time decreased significantly to 122 ± 63 min (p ≤ 0.01). CONCLUSION: The findings suggest that segments such as PE lessons and morning breaks are important sources for MVPA for boys and girls. This should therefore be considered for policies, timetables and curriculums in order to offer sufficient opportunities for children to be physically active during the school day.

Interaction of physical activity and interoception in children.

BACKGROUND: Physical activity (PA) is associated with positive health outcomes, whereas physical inactivity is related to an increased risk for various health issues including obesity and cardiovascular diseases. Previous research indicates that interindividual differences in the perception of bodily processes (interoceptive sensitivity, IS) interact with the degree of PA in adults. Whether there is a similar relationship between PA and IS in children has not been investigated yet. Therefore, the aim of this study was to investigate the interaction between IS and PA during physical performance tasks and in everyday situations. METHODS: IS was assessed using a heartbeat perception task in a sample of 49 children within the health promotion program "Join the Healthy Boat" which is implemented in several primary schools in the southwest of Germany. PA was examined using a physical performance task, assessing the distance covered during a standardized 6-min run. In a subsample of 21 children, everyday PA was measured by a multi-sensor device (Actiheart, CamNtech, Cambridge, UK) during five consecutive days with more than 10 h of daily data collection. RESULTS: Children with higher IS performed better in the physical performance task. Additionally, based on energy expenditure defined as metabolic equivalents, IS was positively correlated with the extent of light PA levels in the morning and afternoon. CONCLUSION: Our findings reveal that IS interacts positively with the degree of PA in children supporting the idea that interoception is important for the self-regulation of health-related behavior.

Does a higher incidence of break times in primary schools result in children being more physically active?

BACKGROUND: Regular physical activity (PA) has multiple benefits to health; however, the majority of schoolchildren do not reach PA guidelines of 60 minutes of moderate to vigorous PA (MVPA) daily. During the school day, break times are often the only opportunity for children to be physically active. This study investigated PA levels during school breaks in German primary school children. METHODS: PA of 294 children (7.1 ± 0.7 years; 48% boys) was assessed. On the basis of timetables, individual activity times and intensities for daily breaks were determined. Children's weight status was determined on site. RESULTS: Breaks lasted 30.7 (± 13.8) minutes; length varied significantly between 1 and 2 breaks (21.7 ± 4.1 versus 36.2 ± 14.8 minutes; p ≤ .01). Children spent 25.3% of their breaks in MVPA, boys being significantly more active (30.8% versus 20.4%; p ≤ .01). Time spent in MVPA differed significantly between normal weight and overweight/obese children (26.1% versus 18.4%; p ≤ .05). Children having 2 breaks engaged in significantly more MVPA than those with only 1 (7.4 ± 6.1 versus 5.6 ± 4.7 minutes; p ≤ .02). CONCLUSIONS: Children spent 25% of their break in MVPA; having 2 breaks increased time in MVPA significantly, although this is also influenced by weight status. Consequently, more activity breaks should be scheduled during school hours.

Intervention effects of a school-based health promotion programme on obesity related behavioural outcomes.

Studies have shown preventive effects of an active lifestyle during childhood on later life; therefore, health promotion has to start early. The programme "Join the Healthy Boat" promotes a healthy lifestyle in primary school children. In order to evaluate it, children's behaviours in respect of increased physical activity (PA), a decrease in screen media use (SMU), more regular breakfast, and a reduction of the consumption of soft drinks (SDC) were investigated. 1943 children (7.1 ± 0.6 years) participated in the cluster-randomised study and were assessed at baseline and 1736 of them at follow-up. Teachers delivered lessons, which included behavioural contracting and budgeting of SMU and SDC. Daily SMU, PA behaviours, SDC, and breakfast patterns were assessed via parental questionnaire. After one-year intervention, significant effects were found in the intervention group for SMU of girls, children without migration background, and children with parents having a low education level. In the control group, second grade children skipped breakfast significantly more often. Tendencies but no significant differences were found for PA and SDC. This intervention seems to affect groups, which are usually hard to reach, such as children of parents with low education levels, which shows that active parental involvement is vital for successful interventions.

Relationship of parental health-related behaviours and physical fitness in girls and boys.

AIM: Physical activity (PA) and physical fitness (PF) are known to be closely connected. Various environmental and biological constraints have been shown to influence children's PA with parents being among strong determinants of their children's PA behaviour. However, little is known about parental influence on PF in children. Therefore, the purpose of this study was to identify the influence of parental health-related behaviours and attitudes on PF in boys and girls. SUBJECTS AND METHODS: Baseline data of 1,875 primary school children (7.1 ± 0.6 years; 50 % male) were included in the analyses. Lateral jumping performance was used as a proxy for whole-body coordination and the 6-min run for cardiovascular fitness. Parental health-related behaviours, attitudes and sociodemographic variables were assessed via questionnaire. Regression analyses, adjusting for age and BMI, were performed separately for boys and girls. RESULTS: The final models of the regression analyses showed that children's age and BMI are significantly related to PF. Mothers' self-efficacy to encourage their children to be active is significantly associated with boys' coordination and cardiovascular fitness and girls' coordination. Mothers' PA affects PF in boys, not in girls. Maternal smoking has a significantly negative effect on both boys' and girls' cardiovascular fitness. CONCLUSION: This study shows that parental health-related behaviours and self-efficacy to encourage their children to be active affect children's PF. Influencing factors, however, differ in girls and boys, and mothers seem especially influential.

Parental Activity as Influence on Children`s BMI Percentiles and Physical Activity.

Parents play a crucial role in the development of their children's lifestyle and health behaviour. This study aims to examine associations between parental physical activity (PA) and children's BMI percentiles (BMIPCT), moderate to vigorous PA (MVPA) as well as participation in organised sports. Height and body weight was measured in 1615 in German children (7.1 ± 0.6 years, 50.3% male) and converted to BMIPCT. Parental BMI was calculated based on self-reported height and body weight. Children's MVPA and sports participation as well as parental PA were assessed via parental questionnaire. Analysis of covariance (ANCOVA), controlling for age and family income was used to examine the association between parental and children's PA levels as well as BMIPCT. 39.7% of the parents classified themselves as physically active and 8.3% of children were classified as overweight or obese. Lower BMIPCT were observed with both parents being physically active (44.5 ± 26.3 vs. 50.2 ± 26.9 and 52.0 ± 28.4, respectively). There was no association between parental and children's PA levels but children with at least one active parent displayed a higher participation in organised sports (102.0 ± 96.6 and 117.7 ± 123.6 vs. 73.7 ± 100.0, respectively). Children of active parents were less likely to be overweight and obese. The lack of association between subjectively assessed parental PA and child MVPA suggests that parental support for PA in children is more important than parents being a role model. More active parents, however, may be more likely to facilitate participation in organised sports. These results underline the importance of the inclusion of parents in health promotion and obesity prevention programmes in children. Key pointsA higher prevalence of overweight or obese children was found with inactive parents.Children's BMI percentiles were lower if both parents were physically active compared to children whose parents were both inactive or only had one physically active parent.Parental activity had no influence on daily time spent at MVPA and time spent in non-organised sports.There was a significant association between parental physical activity and the number of minutes per week boys and girls participated in organised sports.On average, children who had at least one physically active parent spent significantly more time participating in organised sports than children with inactive parents.

Interaction of sedentary behaviour, sports participation and fitness with weight status in elementary school children.

Even though the effect of single components contributing to weight gain in children have been addressed only limited research is available on the combined association of sports participation, physical fitness and time spent watching TV with body weight in children. Baseline data from 1594 children (809 male; 785 female), 7.1 ± 0.6 years of age participating in a large school-based intervention in southern Germany was used. Height and weight was measured and body mass index (BMI) percentiles (BMIPCT) were determined accordingly. Sports participation and time spent watching TV was assessed via parent questionnaire while fitness was determined via a composite fitness test. Combined and single associations of sports participation, TV time and fitness with BMIPCT and weight status were assessed via ANCOVA as well as logistic regression analysis, controlling for age and sex. A significant interaction of TV time, sports participation and fitness on BMIPCT occurred, despite low correlations among the three components. Further, there was a combined association of sports participation and TV time on BMIPCT. TV time and fitness were also independently associated with BMIPCT. Similarly, only increased TV time and lower fitness were associated with a higher odds ratio for overweight/obesity. These results underline the complex interaction of TV time, sports participation and fitness with BMIPCT. In children, TV time and fitness have a stronger influence on BMIPCT compared to sports participation. Sports participation, however, may not reflect overall activity levels of children appropriately. More research is necessary to examine the complex interaction of various behaviours and fitness with BMIPCT.

Objectively determined physical activity levels of primary school children in south-west Germany.

BACKGROUND: Only a small proportion of children and adolescents meet current recommendations of at least 60 min of moderate to vigorous physical activity (MVPA) daily. Most of the available data, however, relies on subjective reports; there is limited objective data on physical activity (PA) levels in German primary school children. The purpose of this study, therefore, was to accurately determine how much time children spend undertaking different intensities of PA and being sedentary during weekdays and weekend using objective assessment tools. Gender-specific and age-related differences were examined along with differences between normal weight and overweight/obese children. METHODS: Children's height and weight were measured according to standard procedures and objective PA measurements were determined in a sub-cohort of 384 primary school children (20% of the whole cohort), participating in a large school-based intervention study in south-west Germany (n = 1947). Baseline data collection occurred on six consecutive days, including weekend days, using multi-sensor accelerometry (Actiheart, CamNtech Ltd., Cambridge UK). 318 children (7.1 ± 0.6 years, male: 50%, first grade: 51%) provided data for at least 3 days including one weekend day. According to the amount of energy expended, defined as metabolic equivalents (METs), different activity intensities were categorised as follows: sedentary < 1.5 METs; light = 1.5-3.0 METs; moderate = 3.0-6.0 METs, and vigorous > 6.0 METs. RESULTS: Average wear time was 1403 ± 94 min/day. Children spent 808 ± 97 min/day being sedentary; 497 ± 72 min/day in light; 128 ± 54 min/day in moderate, and 8 ± 10 min/day in vigorous intensity. 48% of children met the current MVPA guidelines. MVPA was significantly higher on weekdays compared to weekend days (144 ± 66 vs. 113 ± 66 min/day; p < 0.001). Furthermore, boys displayed higher MVPA levels compared to girls (164 ± 57 vs. 106 ± 50 min/day; p < 0.001). CONCLUSION: Measured objectively, less than half of primary school children in the study met current PA recommendations, emphasising the necessity for early intervention to promote PA. Consistent with previous research, PA levels were higher in boys and during weekdays. These results indicate that PA levels of girls should especially be promoted in primary schools and that parents should be more involved in interventions to improve PA, particularly during weekends.

Correlates of weight gain in German children attending elementary school.

OBJECTIVE: To examine the association of physical fitness, sports participation, physical activity and sedentary behavior as well as dietary patterns and family background with weight gain in non-overweight elementary school children, independent of absolute body weight. METHODS: Height, weight, and physical fitness were assessed in 1249 (51% male) children in south-west Germany during the fall of 2010 and 2011 (age at baseline: 7.0±0.6years). Based on changes in body mass index percentiles children were classified into a weight loss, constant weight, or weight gain group. Health behavior and family background were assessed via parent questionnaire. Group differences were examined via analysis of variance and multinomial logistic regression. RESULTS: Weight gain was associated with low physical activity, lack of active transport, and lack of regular breakfast at follow-up. Children in the weight gain category also displayed lower fitness during baseline and follow-up, but differences were more pronounced during follow-up. TV time, migration background or parental education was not associated with weight gain. CONCLUSION: Ensuring adequate physical activity and high fitness is an important aspect in the prevention of excessive weight gain during childhood. In addition to sports participation active transport should be emphasized in future weight management programs in children.

Is central obesity associated with poorer health and health-related quality of life in primary school children? Cross-sectional results from the Baden-Württemberg Study.

BACKGROUND: Childhood obesity and its consequences are a growing threat to national economies and health services. The aim of this study was to determine associations between waist-to-height ratio (WHtR) as a measure of central obesity, and health-related quality of life (HRQoL) and absenteeism of primary school children in the state of Baden-Württemberg, Germany. METHODS: Cross-sectional data from 1888 first and second grade children (7.1±0.6 years) participating in the baseline measurements of the Baden-Württemberg Study were analyzed. Parents completed questionnaires including a rating of their children's HRQoL using KINDLR and EQ5D-Y VAS. Days of absence because of illness, and number of visits to a physician during the last year of school/kindergarten were asked, as well as the number of days parents took off work to care for their sick child. Anthropometric measurements were taken by trained staff. The Mann-Whitney-U test was used for statistical analysis of differences between WHtR groups. Logistic regression models were used to identify factors associated with sick days. RESULTS: A total of 158 (8.4%) children were centrally obese (WHtR ≥0.5). These children had significantly more sick days (9.05 vs. 6.84, p < 0.001) and visits to a physician (3.58 vs. 2.91, p < 0.05), but not days of parental absence than other children. According to regression analysis, sick days were also associated with age, migration status, physical activity pattern, maternal health awareness and family education level. Parent-rated HRQoL was significantly lower in centrally obese children for the EQ5D-Y VAS (88.1 vs. 91.6, p < 0.001), and the KINDLR subscales 'school' (79.9 vs. 82.5, p < 0.05) and 'friends' (75.4 vs. 78.3, p < 0.05), but not for the total score. CONCLUSIONS: Cross-sectional results show higher rates of absence, more visits to a physician and lower HRQoL in children with central obesity. Each missed day at school implies a hazard to academic achievement and each additional visit to a physician is related to higher health care costs. Thus, the negative impact of central obesity is already measurable in primary school children, which emphasizes the urgent need for early delivery of health promotion and targeted prevention.

Evaluation of a health promotion program in children: Study protocol and design of the cluster-randomized Baden-Württemberg primary school study [DRKS-ID: DRKS00000494].

BACKGROUND: Increasing prevalences of overweight and obesity in children are known problems in industrialized countries. Early prevention is important as overweight and obesity persist over time and are related with health problems later in adulthood. "Komm mit in das gesunde Boot - Grundschule" is a school-based program to promote a healthier lifestyle. Main goals of the intervention are to increase physical activity, decrease the consumption of sugar-sweetened beverages, and to decrease time spent sedentary by promoting active choices for healthy lifestyle. The program to date is distributed by 34 project delivery consultants in the state of Baden-Württemberg and is currently implemented in 427 primary schools. The efficacy of this large scale intervention is examined via the Baden-Württemberg Study. METHODS/DESIGN: The Baden-Württemberg Study is a prospective, stratified, cluster-randomized, and longitudinal study with two groups (intervention group and control group). Measurements were taken at the beginning of the academic years 2010/2011 and 2011/2012. Efficacy of the intervention is being assessed using three main outcomes: changes in waist circumference, skinfold thickness and 6 minutes run. Stratified cluster-randomization (according to class grade level) was performed for primary schools; pupils, teachers/principals, and parents were investigated. An approximately balanced number of classes in intervention group and control group could be reached by stratified randomization and was maintained at follow-up. DISCUSSION: At present, "Komm mit in das Gesunde Boot - Grundschule" is the largest school-based health promotion program in Germany. Comparative objective main outcomes are used for the evaluation of efficacy. Simulations showed sufficient power with the existing sample size. Therefore, the results will show whether the promotion of a healthier lifestyle in primary school children is possible using a relatively low effort within a school-based program involving children, teachers and parents. The research team anticipates that not only efficacy will be proven in this study but also expects many other positive effects of the program. TRIAL REGISTRATION: German Clinical Trials Register (DRKS), DRKS-ID: DRKS00000494.