Objectively measured habitual physical activity in 1997/1998 vs 2003/2004 in Danish children: The European Youth Heart Study

Adherence to exercise therapy among children and adolescents with Juvenile idiopathic arthritis: a scoping review

PURPOSE

To identify parameters and measurement methods of exercise therapy adherence, as well as barriers and facilitators affecting adherence among children and adolescents with juvenile idiopathic arthritis (JIA).

METHODS

Studies were eligible for inclusion if patients were 0-18 years of age, had JIA, and the focus of the research was on exercise therapy patterns, measurement/parameters of exercise adherence, and barriers/facilitators for exercise adherence. Two reviewers independently identified and categorized the barriers and facilitators to exercise therapy adherence using the International Classification of Functioning, Disability, and Health (ICF).

RESULTS

Twenty articles were included in this review. Among patients with JIA, 29%-99% adhered to exercise therapy. The most commonly measured parameters of adherence were session completion and behavior component, with a self-report log serving as the most common means of assessment. Time pressure, symptoms related to JIA, lack of enjoyment, and insufficient motivation were the main barriers. Facilitators were commonly identified as adequate motivation, effective symptoms management, and social support.

CONCLUSIONS

Future interventions should consider the identified factors to promote exercise engagement in children and adolescents with JIA. Strategies for promoting exercise adherence in children and adolescents with JIA is needed.

ATHLETIQUE: interest of an adapted physical activity program in patients with juvenile idiopathic arthritis: a feasibility and preliminary effectiveness study

Background

Juvenile Idiopathic Arthritis (JIA) is associated with joint inflammation, pain and limited joint mobility, impacting the practice of physical activities. Adapted Physical Activities (APA) are an increasingly used method of rehabilitation, but additional studies are needed to define the nature of the most appropriate physical activity for patients with JIA. The "ATHLETIQUE" project aims to evaluate the impact of a program integrating APA sessions with use of a pedometer watch, on disease activity in patients with JIA.

Methods

This study will be a randomized, multicenter, open-label, controlled clinical trial with 2 parallel arms. The patients included in this study will be children and adolescents with JIA, aged 6 to 17 years. The experimental group (30 patients) will participate in an APA program for 3 months and will use a pedometer watch for one year. We will evaluate and compare the change in disease activity measurements (primary objective), fatigue, pain, quality of life, level of physical activity, functional capacities, and muscle strength (secondary objectives) after 14, 26 and 50 weeks. The control group (10 patients) will undergo the same evaluations as the experimental group but will not participate in the APA program and will not wear the pedometer watch.

Expected results

The APA program may help to promote an active lifestyle with regular physical activity, preventing comorbidities and motor disability. Promising results on disease activity, functional capacities and quality of life would enable us to envisage a larger research program with a view to optimizing and assessing APA for children with JIA.

Discussion

This study will be conducted in the short and medium-term, with one-year follow-up, including 3 months of APA sessions for the experimental group. The sessions proposed during the APA program will mainly be aerobic and bodyweight exercises. Furthermore, in contrast to previous studies on this topic, our study will integrate a novel element, namely the use of a pedometer watch. This watch will help to implement strategies to address motivation. This study aims to improve physical and mental well-being, provide a basis for the design of a larger study, and propose recommendations adapted to children with JIA.

Trial registration

Registered with ClinicalTrials.gov under the number NCT05572424.

The Differential Impact of Screen Time on Children's Wellbeing

Increased screen time has been found to be associated with a number of negative health and wellbeing indicators in youth populations. An increasing number of studies have investigated the association between screen time and wellbeing in adolescents, but evidence in younger children is still emerging. This 2017 study explored the effect of leisure screen time and gender on dimensions of wellbeing (measured using KIDSCREEN-27) in a national sample of 897 Irish primary school children aged 8-12 years. Participants had a mean age of 10.9 ± 1.16 years and were 47.7% female. Just over 30% of the sample accumulated 2 h or more of leisure screen time daily. Results show that there was no significant interaction between screen time category (<2 h/2 h + daily) and gender on overall wellbeing, while controlling for BMI. Children who self-reported <2 h of leisure screen time scored significantly higher on four dimensions of wellbeing: physical, parental, peers, and school, but not psychological. This study supports the growing evidence of the impact that leisure screen time has on health. Further longitudinal research investigating the impact of sub-categories of leisure screen time behaviour on wellbeing is warranted.

Temporal trends in physical activity levels across more than a decade - a national physical activity surveillance system among Norwegian children and adolescents

BACKGROUND

There is a scarcity of device measured data on temporal changes in physical activity (PA) in large population-based samples. The purpose of this study is to describe gender and age-group specific temporal trends in device measured PA between 2005, 2011 and 2018 by comparing three nationally representative samples of children and adolescents.

METHODS

Norwegian children and adolescents (6, 9 and 15-year-olds) were invited to participate in 2005 (only 9- and 15-year-olds), 2011 and 2018 through cluster sampling (schools primary sampling units). A combined sample of 9500 individuals participated. Physical activity was assessed by hip worn accelerometers, with PA indices including overall PA (counts per minute), moderate-to-vigorous intensity PA (MVPA), and PA guideline adherence (achieving on average ≥ 60 min/day of moderate-to-vigorous PA). Random-effects linear regressions and logistic regressions adjusted for school-level clusters were used to analyse temporal trends.

FINDINGS

In total, 8186 of the participating children and adolescents provided valid PA data. Proportions of sufficiently active 6-year-olds were almost identical in 2011 and 2018; boys 95% (95% CI: 92, 97) and 94% (95%CI: 92, 96) and girls 86% (95% CI: 83, 90) and 86% (95% CI: 82, 90). Proportions of sufficiently active 15-year-olds in 2005 and 2018 were 52% (95% CI: 46, 59) and 55% (95% CI: 48, 62) in boys, and 48% (95% CI: 42, 55) and 44% (95% CI: 37, 51) in girls, respectively, resulting from small differences in min/day of MVPA. Among 9-year-old boys and girls, proportions of sufficiently active declined between 2005 and 2018, from 90% (95% CI: 87, 93) to 84% (95% CI: 80, 87)) and 74% (95% CI: 69, 79) to 68% (95% CI: 64, 72), respectively. This resulted from 9.7 min/day less MVPA in boys (95% CI: - 14.8, - 4.7; p < 0.001) and 3.2 min/day less MVPA (95% CI: - 7.0, 0.7; p = 0.106) in girls.

CONCLUSIONS

PA levels have been fairly stable between 2005, 2011 and 2018 in Norwegian youth. However, the declining PA level among 9-year-old boys and the low proportion of 15-year-olds sufficiently active is concerning. To evaluate the effect of, and plan for new, PA promoting strategies, it is important to ensure more frequent, systematic, device-based monitoring of population-levels of PA.

Weekly variation in markers of cardiometabolic health - the possible effect of weekend behavior - a cross-sectional study

Background

Adolescents’ health-related behavior varies from weekday to weekend. Only few studies, however, have examined to which degree such variation will affect markers of cardiometabolic health. Therefore, the primary aim of this study is to examine if markers of cardiometabolic health differ between different days of the week in adolescents.

Methods

This cross-sectional school-based study included up to 581 participants, 11–17 years old. Markers of metabolic health were insulin, glucose, triglyceride, HDL-cholesterol (HDL-C), LDL-cholesterol (LDL-C) and blood pressure. Linear mixed regression modelling was used to examine the cardiometabolic profile across weekdays.

Results

Significant declining trends were observed across the week in adolescents’ levels of cardiometabolic health markers. Lower levels of insulin (16.1%), glucose (2.6%) and triglyceride (24.7%) were observed on Fridays compared to Mondays (p ≤ 0.006). Gradual improvement in measurement profiles across weekdays was less apparent for HDL-C, LDL-C, systolic blood pressure and diastolic blood pressure (P ≥ 0.06). Analyses stratified by sex suggested a more noticeable pattern of gradual improvement across weekdays in boys than in girls.

Conclusion

Significantly lower levels of insulin, glucose and triglyceride were observed in adolescents on Fridays compared to Mondays. However, when sex specific analyses were performed significant profile variations were only observed across the week in boys. More research is needed to better understand which behavioral factors in particular seem to influence weekly variation in markers of cardiometabolic health - especially since such variation potentially will have an impact on how assessments of markers of cardiometabolic health optimally should be planned, standardized and carried out, both in research and in medical practice.

Relationship Between the Practice of Physical Activity and Physical Fitness in Physical Education Students: The Integrated Regulation As a Mediating Variable

The practice of physical activity (PA) contributes to the prevention of chronic diseases such as obesity, metabolic syndrome or cardiovascular diseases, being also directly related to the individual’s physical fitness. Therefore, it is necessary to measure and monitoring the levels of PA in childhood and adolescence, since it may be useful to describe their current health status and the association with physical fitness, as well as to reveal putative consequences in the future. Within the educational field, it has been shown that physical education (PE) classes are a favorable context for the creation of healthy physical-sports habits and self-determined motivation could be a key for explaining the level of PA practice. For this reason, the purpose of this research was to study the mediating role of integrated regulation (IR) on the relationship between PA and physical fitness in children and adolescents. A total of 325 students between 11 and 14 years old participated in the study. The level of PA was estimated through the specific Physical Activity Questionnaire for Children (PAQ-C), while motivation and IR were measured by using the Perceived Locus of Causality scale (PLOC-2). In addition, physical fitness was measured through the Eurofit fitness battery of tests, composed of three body composition measures and seven tests of different physical capacities. The physical fitness score showed no differences when genders were compared. After regression analysis, the resulting models revealed a good adjustment and correlation between PA practice and physical fitness (β = 0.173; p < 0.001), being established through the macro Process that this relationship is partially conditioned by the IR (β = 0.122; p = 0.03). ROC curve analysis estimated the score of 5.88 as a cut-off point to discriminate between levels of IR for students, classified as physically active or not (AUC = 0.67; p < 0.001). The conclusions from these main and other complementary analyses reporting complete mediations, suggest that the IR could be decisive in predicting and explaining the relationship between the practice of PA and physical fitness at these ages, highlighting its importance for a greater adherence to the practice.

Temporal Trends of Compliance With School-Based Physical Activity Recommendations Among Spanish Children, 2011-2018

BACKGROUND

According to the current physical activity (PA) recommendations, children should accumulate 60 minutes of moderate to vigorous PA (MVPA) throughout the day, 30 minutes of MVPA during the school hours, and 50% of the recess time in MVPA. Our aim was to examine the temporal trends of accelerometer-based PA during the previously mentioned day segments and the proportion of children who met the PA recommendations.

METHODS

This was a cross-sectional study with 2 independent samples: 499 fourth graders (49.2% females) in 2011-2012 and 364 fourth graders (46.9% females) in 2017-2018. Hip-worn accelerometers were used to assess PA.

RESULTS

A decline in light PA, moderate PA, vigorous PA, MVPA, and total PA during whole day, and in the rate of compliance with daily MVPA recommendations in males (P < .01) was observed from 2011-2012 to 2017-2018. Females decreased their daily light PA and moderate PA (P < .05). A decline in all PA variables during school hours in both sexes (P < .05) and in the rate of compliance with the 30 minutes of MVPA recommended during school hours in males (P < .001) were observed. There were no differences in PA during recesses.

CONCLUSIONS

Interventions are needed to attenuate the temporal decrease in PA levels in children.

Variations in accelerometry measured physical activity and sedentary time across Europe - harmonized analyses of 47,497 children and adolescents

Background

Levels of physical activity and variation in physical activity and sedentary time by place and person in European children and adolescents are largely unknown. The objective of the study was to assess the variations in objectively measured physical activity and sedentary time in children and adolescents across Europe.

Methods

Six databases were systematically searched to identify pan-European and national data sets on physical activity and sedentary time assessed by the same accelerometer in children (2 to 9.9 years) and adolescents (≥10 to 18 years). We harmonized individual-level data by reprocessing hip-worn raw accelerometer data files from 30 different studies conducted between 1997 and 2014, representing 47,497 individuals (2–18 years) from 18 different European countries.

Results

Overall, a maximum of 29% (95% CI: 25, 33) of children and 29% (95% CI: 25, 32) of adolescents were categorized as sufficiently physically active. We observed substantial country- and region-specific differences in physical activity and sedentary time, with lower physical activity levels and prevalence estimates in Southern European countries. Boys were more active and less sedentary in all age-categories. The onset of age-related lowering or leveling-off of physical activity and increase in sedentary time seems to become apparent at around 6 to 7 years of age.

Conclusions

Two third of European children and adolescents are not sufficiently active. Our findings suggest substantial gender-, country- and region-specific differences in physical activity. These results should encourage policymakers, governments, and local and national stakeholders to take action to facilitate an increase in the physical activity levels of young people across Europe.

Why are children different in their moderate-to-vigorous physical activity levels? A multilevel analysis

OBJECTIVE

Children's differences in moderate-to-vigorous physical activity levels are not at random. This study investigates the relevance of individual- and school-level characteristics in explaining these differences.

METHODS

In total, 307 children (154 girls) aged 5-10 years, from 19 Portuguese schools, were sampled. Height and weight were measured, and body mass index was calculated. Time spent in moderate-to-vigorous physical activity was measured by accelerometry. Gross motor coordination was assessed with the KörperkoordinationsTest für Kinder battery and socio-economic status was obtained via the school social support system. School characteristics were obtained with an objective school audit. A multilevel analysis was used as implemented in Stata 15.

RESULTS

Schools explained 18.2% of the total variance in moderate-to-vigorous physical activity, with the remainder being ascribed to children's distinct characteristics. Boys were more active (β=29.59±11.52, p<0.05), and having higher gross motor coordination levels (β=0.11±0.04, p<0.05) was positively associated with daily moderate-to-vigorous physical activity, whereas being older (β=-5.00±1.57, p<0.05) and having higher socio-economic status (β=-7.89±3.12, p<0.05) were negatively related with moderate-to-vigorous physical activity. From the school-level correlates, only playground dimension was significantly associated with moderate-to-vigorous physical activity levels. Children from schools with medium (40m² to 69m²) and large playground dimensions (≥70m²) were less active than children with smaller playground dimensions (10m² to 39m²).

CONCLUSIONS

Variation in school children's moderate-to-vigorous physical activity is mostly explained by their individual characteristics; school characteristics also play a role but to a smaller degree. Future intervention programs to change this behavior should be more personalized, emphasizing mostly individual-level characteristics.

Secular changes in total steps and moderate-to-vigorous physical activity among fourth-grade students in Japan in 2003/2004 and 2016/2017

No study has investigated secular changes in both total steps and moderate-to-vigorous physical activity (MVPA) among Japanese children. This study examined the secular changes of total steps and MVPA among fourth-grade students in Japan in 2003/2004 and 2016/2017. It was performed at a school in Okayama Prefecture in Japan. A total of 452 participants (226 boys and 226 girls; mean age, 9.6 ± 0.5 years) participated in the study. We measured total steps and MVPA of the participants by using the same methods in 2003/2004 and 2016/2017. An uniaxial accelerometer was used to measure total steps and MVPA. On weekdays and weekends, the total steps and MVPA were lowered by approximately 1,000-3,000 steps/day and 10 min/day, respectively, in boys and by 1,000 steps/day and 5 min/day, respectively, in girls in 2016/2017 in comparison to 2003/2004. In both boys and girls, the percentage of children meeting 60 minutes/day of MVPA decreased in 2016/2017(weekdays: boys 21.8%, girls 6.0%; weekends: boys 3.8%, girls 4.1%) compared with 2003/2004 (weekdays: boys 48.2%, girls 11.6%; weekends: boys 7.8%, girls 7.6%). In conclusion, the results demonstrated that total steps and MVPA of fourth-grade students in Japan were lower in 2016/2017 than in 2003/2004.

Specific Sports Habits, Leisure-Time Physical Activity, and School-Educational Physical Activity in Children With Juvenile Idiopathic Arthritis: Patterns and Barriers

OBJECTIVE

Juvenile idiopathic arthritis (JIA) may cause functional impairment and reduced time engaged in physical activity. The aim of this study was to investigate the habits of patients with JIA regarding participation in club sports, leisure-time physical activity, and school-educational physical activity and relate this to objectively measured physical activity using accelerometry and to compare the findings with those in healthy controls.

METHODS

Consecutive patients from the Aarhus University Hospital outpatient clinic were included. Clinical characteristics, functional ability, and exploration of specific habits in club sports, leisure-time physical activity, and school-educational physical activity (based on a standardized questionnaire) in patients were recorded and compared with those in healthy controls. The intensity and frequency of physical activity were measured by accelerometer monitoring, using ActiGraph GT1M.

RESULTS

Sixty-eight patients with JIA and 118 healthy control subjects were included. Despite having low disease activity, children with JIA had significantly lower accelerometry-monitored physical activity levels compared with healthy controls. The distribution of specific club sport activities was the same among patients and controls. However, the proportion of patients spending >3 hours/week participating in club sports was significantly lower than the proportion of controls, whereas no difference in time spent engaging in physical activity during leisure-time was observed. Participation in compulsory school-educational physical activity was equally high in patients and controls, although participation by patients was significantly less consistent than that by controls. Patient reports of time spent with club sport and leisure-time physical activity was significantly related to accelerometry measures, whereas this was not observed for school-educational physical activity.

CONCLUSION

The results of this study indicate the need for structured guidance for all patients with JIA (including those with minimal disease activity) in both understanding and coping with the consequences of a low level of physical activity.

Comparisons of pedometer-determined weekday physical activity among Swedish school children and adolescents in 2000 and 2017 showed the highest reductions in adolescents

AIM

This study compared differences in weekday physical activity among school children and adolescents in middle-class communities in south-eastern Sweden in 2000 and 2017.

METHODS

Data were drawn from two independent cross-sectional cohorts of children and adolescents aged 8, 11 and 14. The same six schools, protocols, procedures and instruments were used in both years, with 332 subjects in 2000 and 562 in 2017. Mean steps per day (SPD) were measured with a Yamax SW-200 pedometer.

RESULTS

The mean weekday SPD was similar among eight-year-old girls in both years, but 8% (p = 0.040) higher among eight-year-old boys in 2017. However, among 11-year-old children, the mean SPD were 12% lower among both girls (p = 0.033) and boys (p = 0.001). The SPD among 14-year-old adolescents were 24% (p = 0.012) and 30% (p < 0.001) lower among girls and boys, respectively.

CONCLUSION

This school-based study from south-eastern Sweden showed that weekday physical activity differed between age groups in 2000 and 2017. The highest reductions were seen among older children and adolescents, particularly 14-year-old girls and boys. The only group that increased was eight-year-old boys, with no significant change in eight-year-old girls. A possible explanation might be the dramatically increased use of the Internet on phones and tablets.

The validity of the Youth Physical Activity Questionnaire in 12-13-year-old Scottish adolescents

BACKGROUND

The development of accurate methods to measure health-behaviours forms an integral component in behavioural epidemiology. Population surveillance of physical activity often relies on self/proxy reported questionnaires due to cost and relative ease of administration. The aim of this study was to examine the criterion validity and measurement agreement between the Youth Physical Activity Questionnaire (YPAQ) and accelerometry before being included in a Scotland-wide study.

METHODS

Forty four participants (12-13 years old; 61% girls) completed the YPAQ following 7 days wearing the Actigraph GT3X+. Mean moderate-to-vigorous physical activity (MVPA) per day was derived from YPAQ and accelerometer and validity was assessed using Spearman's correlation; Bland-Altman plots examined absolute agreement between methods.

RESULTS

Pearson's and Spearman's correlations between YPAQ and accelerometer were r = 0.47 and rs = 0.39 (p<0.01) respectively. The YPAQ over reported mean MVPA by 25.6 ± 50.2 minutes (95% CI 10.4-40.9 minutes; p <0.001), with 95% limits of agreement of -72.69 minutes and + 123.99 minutes. Evidence of underreporting at lower levels of activity and over reporting at higher levels of activity was evident (Pearson's r=0.81), in addition to heteroscedasticity, where variances increased as MVPA increased.

CONCLUSIONS

Although a moderate correlation between the two methods was apparent, the YPAQ should not be used interchangeably with accelerometry. The YPAQ does demonstrate a reasonable ability to rank MVPA, although it tends to under-report lower levels and over-report higher levels. This, and other administering factors, should be taken into consideration if being used for group or individual level analyses.

No difference in the level of physical activity between children who have or have never sustained a fracture

This study investigates whether children with an acute fracture have a different level of physical activity compared to children who have never sustained a fracture, as measured by the Physical Activity Questionnaire for older children (PAQ-C). The PAQ-C scores of 683 children (295 girls) aged 6-12 years (mean age 9.4 years) who presented to our institution with an acute fracture were compared to the PAQ-C scores of 151 random children (81 girls) aged 6-12 years (mean 9.1 years) in the same area who had never sustained a fracture. Multivariate regression analysis was employed, controlling for age and gender. The mean PAQ-C score of the children who presented to the institution with an acute fracture was 2.85 (95% confidence interval [CI], 2.80-2.91). For the children who had never sustained a fracture, the mean PAQ-C score was 2.78 (95% CI, 2.69-2.87). If there is a true difference in the level of physical activity between children who have or have never sustained a fracture, the PAQ-C questionnaire is not sensitive enough to identify it.

Physical activity decreased by a quarter in the 11- to 12-year-old Swedish boys between 2000 and 2013 but was stable in girls: a smartphone effect?

AIM

This study explored physical activity, body mass index (BMI) and overweight and obesity from 2000 to 2013 using a convenience sample of second- and fifth-grade Swedish schoolchildren aged 8-9 years and 11-12 years, respectively.

METHODS

We examined cross-sectional cohorts of 126 second-grade children in 2000, 84 in 2006 and 44 in 2013 and 105 fifth-grade children in 2000 and 38 in 2013. No fifth graders were available in 2006. Physical activity data were collected based on pedometer readings over four consecutive weekdays, and height and weight were measured. Identical instruments and procedures were used in all three years.

RESULTS

There was an increase in physical activity in second-grade girls from 2000 to 2006 (p < 0.01), which then stabilised between 2006 and 2013, but second-grade boys and fifth-grade girls were stable throughout the study period. Fifth-grade boys decreased significantly (24%) from 16 670 to 12 704 steps per day (p < 0.01) from 2000 to 2013. Mean BMI scores remained stable over time.

CONCLUSION

Time trends in physical activity differed between boys and girls. Second-grade boys and fifth-grade girls were stable throughout, whereas second-grade girls increased from 2000 to 2006 before stabilising. Fifth-grade boys showed a significant 24% reduction from 2000 to 2013. Changes in recess and leisure time habits, such as smartphone use, may have influenced the result.

Parental education and physical activity in pre-school children

BACKGROUND

The purpose of this study was to objectively assess pre-school children's total physical activity (TPA) patterns and compliance with guidelines and to examine differences relative to parental education.

METHODS

The sample consisted on 509 healthy pre-school children, aged 3-6 years recruited from kindergartens located in the metropolitan area of Porto, Portugal. The PA was assessed for 7 consecutive days by accelerometry. For TPA, we followed the guidelines of the National Association for Sport and Physical Education (NASPE) (children who spent at least >120  min per day in active play). For TPA, we calculated the proportion of children who spent at least >120  min per day in active play and moderate-to-vigorous physical activity (MVPA), we calculated the proportion of children who spent at least >60  min per day in active play. Parental education was analysed according to the Portuguese education system.

RESULTS

Children with parents in the highest education level were less active than children from low and middle education level (P ≤ 0.001) in all patterns of PA (week and weekend). Regarding TPA during the week we found that the majority of children from low and middle parental education meet the NASPE guidelines. On the other hand, more than half the children from high parental education did not meet these recommendations (P ≤ 0.001) and MVPA recommendations (P ≤ 0.05). In both recommendations, children from low parental education were twice more likely to meet the recommendations compared with children belonging to high parental education.

CONCLUSION

Parent education was negatively associated with children's daily physical activity patterns and compliance with guidelines.

Health-Related Physical Activity Levels in Spanish Youth and Young Adults

The aim of this study was to analyze the current physical activity (PA) levels in youth and young adults from Granada, Spain, and to assess if they accomplish the recommendations for healthy PA. A sample of 1,832 boys and 1,840 girls was administered the International Physical Activity Questionnaire. Results showed that most of the children (72.2%) and adolescents (56.4%) reached the recommended PA levels, whereas only 40% of young adults achieved recommended levels of PA. The most active were students from Primary schools, whereas university students were the least active. Youth of college and university ages were found to be at higher risk for engagement in PA.

Obesity and physical activity patterns in children and adolescents

AIM

The aim of this study is to measure objectively and accurately the physical activity (PA) patterns in Spanish children and adolescents according to their obesity status, gender and age groups.

METHODS

A sample of 487 children and 274 adolescents from the European Youth Heart Study participated in the study. The variables measured were anthropometric characteristics (height, weight and body mass index), and PA was measured during 6 consecutive days using the GT1M accelerometer.

RESULTS

Three-way analysis of variance (age × gender × obesity status) showed significant differences in the interaction effect in age, gender and obesity status (normal-weight and overweight/obesity) for mean of moderate-to-vigorous PA (MVPA) (P = 0.02) and vigorous PA (VPA) (P = 0.014) within the sample. Nine-year-old normal-weight children achieved significantly (P < 0.05) more MVPA on weekdays than 9-year-old overweight/obesity children. During weekend days, all sample achieved significant more MVPA (P < 0.01) and significant more VPA (P < 0.05) than during weekdays. Few children (37.5% of 9-year-old normal-weight and 34.0% of 9-year-old overweight/obese) and adolescents (16.4% and 27.3% normal-weight and overweight/obese, respectively) met the current health-related recommendations of 60 min of MVPA daily.

CONCLUSIONS

It is clear that activity levels are insufficient for all children, in particular overweight/obese children and adolescents, although the precise nature of the relationship appears to differ between boys and girls.

The intensity of physical activity influences bone mineral accrual in childhood: the childhood health, activity and motor performance school (the CHAMPS) study, Denmark

Background

Studies indicate genetic and lifestyle factors can contribute to optimal bone development. In particular, the intensity level of physical activity may have an impact on bone health. This study aims to assess the relationship between physical activity at different intensities and Bone Mineral Content (BMC), Bone Mineral Density (BMD) and Bone Area (BA) accretion.

Methods

This longitudinal study is a part of The CHAMPS study-DK. Whole-body DXA scans were performed at baseline and after two years follows up. BMC, BMD, and BA were measured. The total body less head (TBLH) values were used. Physical activity (PA) was recorded by accelerometers (ActiGraph, model GT3X). Percentages of different PA intensity levels were calculated and log odds of two intensity levels of activity relative to the third level were calculated. Multilevel regression analyses were used to assess the relationship between the categories of physical activity and bone traits.

Results

Of 800 invited children, 742 (93%) accepted to participate. Of these, 682/742 (92%) participated at follow up. Complete datasets were obtained in 602/742 (81%) children. Mean (range) of age was 11.5 years (9.7-13.9). PA at different intensity levels was for boys and girls respectively, sedentary 62% and 64%, low 29% for both genders and moderate to high 9% and 7% of the total time. Mean (range) BMC, BMD, and BA was 1179 g (563–2326), 0.84 g/cm² (0.64-1.15) and 1393 cm² (851–2164), respectively. Valid accelerometer data were obtained for a mean of 6.1 days, 13 hours per day.

Conclusions

There 7was a positive relationship between the log odds of moderate to high-level PA versus low level activity and BMC, BMD and BA. Children with an increased proportion of time in moderate to high-level activity as opposed to sedentary and low-level activity achieved positive effects on BMC, BMD and BA.

A cross-cultural study of adolescents' physical activity levels in France and Spain

The goals of this study were (1) to describe and compare levels of physical activity (PA), assessed by accelerometry, of adolescents in two close Spanish and French cities according to gender and period of the week and (2) to assess, with reference to country and gender, the extent to which international PA guidelines were fulfilled. The PA of 401 adolescents (53.37% females) from France and Spain (55.72% French) aged 14.45 ± 0.67 years was assessed with GT3X accelerometers for seven consecutive days to evaluate their habitual levels of moderate to vigorous physical activity (MVPA). Data collection took place from September to December 2010 in six public and state schools in France and Spain. There were significant differences in MVPA in terms of country, gender and period of the week. Spanish adolescents were more active than French adolescents, boys were more active than girls and MVPA was higher on weekdays than at weekends. French girls showed the lowest level of PA. Only 35.9% of the whole sample met the guidelines for PA in both countries. Governments of relevant countries, especially France, should adopt PA promotion policies targeted at adolescents in order to enhance their compliance with PA guidelines.

Tracking of accelerometry-measured physical activity during childhood: ICAD pooled analysis

Background

Understanding of physical activity (PA) tracking during childhood is important to predict PA behaviors and design appropriate interventions. We compared tracking of PA according to PA level and type of day (weekday/weekend) in a pool of five children’s cohort studies.

Methods

Data from ALSPAC, CLAN, Iowa Bone Development Study, HEAPS, PEACH were extracted from the International Children’s Accelerometry Database (ICAD), resulting in 5,016 participants with age, gender, and accelerometry data at both baseline and follow-up (mean age: 10.3 years at baseline, 12.5 years at follow-up). Daily minutes spent in moderate- and vigorous-intensity PA (MVPA) and vigorous-intensity PA (VPA) was categorized into quintiles. Multinomial logistic regression models were fit to predict follow-up (M)VPA from baseline (M)VPA (reference: 20- < 80%tile), age at follow-up, and follow-up duration.

Results

For the weekday, VPA tracking for boys with high baseline VPA was higher than boys with low baseline VPA (ORs: 3.9 [95% CI: 3.1, 5.0] vs. 2.1 [95% CI: 1.6, 2.6]). Among girls, high VPA was less stable when compared low VPA (ORs: 1.8 [95% CI: 1.4, 2.2] vs. 2.6 [95% CI: 2.1, 3.2]). The pattern was similar for MVPA among girls (ORs: 1.6 [95% CI: 1.2, 2.0] vs. 2.8 [95% CI: 2.3, 3.6]). Overall, tracking was lower for the weekend.

Conclusions

PA tracking was higher on the weekday than the weekend, and among inactive girls than active girls. The PA “routine” of weekdays should be used to help children establish healthy PA patterns. Supports for PA increase and maintenance of girls are needed.

Bicycling to school improves the cardiometabolic risk factor profile: a randomised controlled trial

OBJECTIVES

To investigate whether bicycling to school improves cardiometabolic risk factor profile and cardiorespiratory fitness among children.

DESIGN

Prospective, blinded, randomised controlled trial.

SETTING

Single centre study in Odense, Denmark

PARTICIPANTS

43 children previously not bicycling to school were randomly allocated to control group (n=20) (ie, no change in lifestyle) or intervention group (ie, bicycling to school) (n=23).

PRIMARY AND SECONDARY OUTCOME MEASURES

Change in cardiometabolic risk factor score and change in cardiorespiratory fitness.

RESULTS

All participants measured at baseline returned at follow-up. Based upon intention-to-treat (ITT) analyses, clustering of cardiometabolic risk factors was lowered by 0.58 SD (95% CI -1.03 to -0.14, p=0.012) in the bicycling group compared to the control group. Cardiorespiratory fitness (l O(2)/min) per se did not increase significantly more in the intervention than in the control group (β=0.0337, 95% CI -0.06 to 0.12, p=0.458).

CONCLUSIONS

Bicycling to school counteracted a clustering of cardiometabolic risk factors and should thus be recognised as potential prevention of type 2 diabetes mellitus and cardiovascular disease (CVD). The intervention did, however, not elicit a larger increase in cardiorespiratory fitness in the intervention group as compared with the control group.

TRIAL REGISTRATION

Registered at http://www.clinicaltrials.gov (NCT01236222).

Television viewing, food preferences, and food habits among children: a prospective epidemiological study

Background

Obesity has increased since the early 1980s, and despite numerous attempts, effective strategies to counter this worldwide epidemic are lacking. Food preferences are established early in life and are difficult to change later. There is therefore a need to identify factors that influence the development of food preferences. Our aim was therefore, to investigate cross-sectional and prospective associations between TV viewing habits and food preferences and habits, respectively. We hypothesized that more TV viewing was associated with less healthy concomitant and future food preferences and food habits.

Methods

Data are from the Danish part of European Youth Heart Study (EYHS) I and II, a prospective cohort study conducted among 8-10-year-old and 14-16-year-old Danes in 1997-98. Six years later 2003-04 the 8-10-year-olds were followed up at age 14-16 years, and a new group of 8-10-year olds were included. Data were analysed using mixed linear regression analysis. Cross-sectional analyses included 697 8-10-year-olds and 495 14-16-year-olds. Prospective analyses included 232 pupils with complete data at baseline and follow-up. Associations between TV viewing habits and the sum of healthy food preferences (ΣHFP), and the sum of healthy food habits (ΣHFH), respectively, were examined.

Results

Inverse cross-sectional associations between TV viewing (h/day) and both ΣHFP and ΣHFH were present for both the 8-10-year-old and the 14-16-year-old boys and girls. The frequency of meals in front of the TV (times/week) was also inversely associated with ΣHFP among 8-10-year-old boys, and with ΣHFH in all sex- and age groups. Among girls, baseline TV viewing (h/day) was directly associated with adverse development in the ΣHFP during follow-up. The concomitant 6-year changes in ΣHFH and TV viewing (h/day) were inversely associated in boys.

Conclusions

Long time spent on TV viewing, and possibly to a lesser degree, frequent consumption of meals during TV viewing, seem to be associated with generally having unhealthy food preferences and food habits among school-aged children. These associations, however, were not generally persistent after 6 years of follow-up.