Patterns of physical activity in Spanish children: a descriptive pilot study

Planetary health diet versus usual diet in adolescents. How do food and physical activity influence academic performance?

Introduction

Objective: to analyze the relationship of the similarity of planetary health diet and habitual diet with the practice of physical activity on the academic performance of adolescent high school students by gender. Method: 877 adolescents were evaluated. The diet is reviewed through the 24-hour reminder. Physical activity was classified according to type of activity, frequency, duration, and intensity using the APALQ questionnaire. The caloric intake of adolescents was compared with the proposal of the EAT-LANCET commission, and the relationship between physical activity and diet with academic performance was again established. Results: Mexican adolescents do not comply with the proposal of a planetary health diet. No relationship was found between physical activity and academic performance. On the other hand, animal proteins rich in fats are consumed doubly according to the recommendation; these and whole grains, both are inversely related to better academic performance. Conclusions: Mexican adolescents are far from consuming a planetary health diet. Physical activity was not related to academic performance, but there is an inverse relationship between fat-rich animal proteins and whole grains in relation to subjects that contribute to academic performance, which suggests that a healthy diet such as the planetary diet proposal could have an impact on environmental sustainability and favorably impact the academic performance of adolescents.

Associations between Self-Perceived and Desired Health-Related Physical Fitness in Spanish Children

Health-related physical fitness (HRPF) has emerged as an important marker of health among children. It is usually defined as a multidimensional construct consisting of cardiorespiratory endurance; muscular strength and endurance; and flexibility. Currently, health policies are aimed at getting children to increase their HRPF levels. Understanding the relationship between the perceived and the desired levels of fitness can be important to avoid the abandoning of physical activity practice. We analyzed the associations between the self-perceived and the desired health-related physical fitness. A modified version of the self-perceived HRPF questionnaire was completed by 330 children (148 girls, mean age: 10.78 ± 0.67 years, and 182 boys, mean age: 10.82 ± 0.61 years). Fitness was measured through tests selected from the Eurofit battery. The questions regarding desired HRPF showed moderate internal consistency (Cronbach’s α: 0.671) and good test–retest reliability (ICC: 0.761). In general, children shared a desire to improve their self-perceived HRPF. Those who perceived themselves as already being fit were the ones who showed the strongest desire for achieving higher HRPF levels.

Prediction Model for Physical Activity Level in Primary School Students

The aim of this study was to provide an explanatory prediction model for physical activity level in children, involving a number of influencing variables. In total, 1971 people participated in the study: 657 primary school students and their respective fathers and mothers from 15 schools of Galicia (Spain). The International Questionnaire on Physical Education, Health and Lifestyle was administered. The findings revealed that school year, sex, physical perceived competence and sport practice with friends had a statistically significant relationship on physical activity index. By contrast, the association between the weekly participation of fathers or mothers in sports in the practice of children could not be confirmed. Sport practice with friends was the main predicting variable for physical activity level. Physical perceived competence showed great relevance as well. This knowledge could be of interest to help increase adherence to practice and preventing withdrawal, helping students to stay active and acquire healthy habits for the future.

Association of Diet, Physical Activity Guidelines and Cardiometabolic Risk Markers in Children

The aim was to identify different dietary and physical activity (PA) patterns in 5- to 14-year-old children with a high prevalence of overweight and obesity using cluster analysis based on their adherence to the Spanish Society of Community Nutrition dietary guidelines and levels of PA, and to determine their associations with age, sex, body composition, and cardiometabolic risk markers. In 549 children, hierarchical cluster analysis was used to identify subgroups with similar adherence to dietary recommendations and level of PA. Three clusters were identified: Cluster 1, with the lowest level of vigorous PA and adherence to dietary recommendations; Cluster 2, with the lowest levels of moderate and vigorous PA and the highest adherence to dietary recommendations; and Cluster 3, with the highest level of PA, especially vigorous PA and a medium level adherence to dietary recommendations. Cluster 3 had lower total body fat and higher lean body mass percentages than Cluster 2. Cluster 2 had lower high-density lipoprotein cholesterol and higher low-density lipoprotein cholesterol levels than Cluster 1. The results from our study suggest that it is important to consider adherence to PA recommendations together with adherence to dietary guidelines to understand patterns of obesogenic habits in pediatric populations with high prevalence of overweight and obesity.

Socio-Emotional Skills in Adolescence. Influence of Personal and Extracurricular Variables

Social-emotional skills have been an important object of study in recent years due to their relationship with academic, personal and professional success. The aim of this study was to analyse the relationship between these skills and different influential variables. The participants had a mean age of 14.18 years. The instruments used were the Social Emotional Competence Questionnaire (SECQ) and the Physical Activity Questionnaire for Adolescents (PACQ-A). Generally, the results indicated gender differences and no influence of age. Those who engaged in after-school activities scored higher on social awareness. In addition, artistic and musical extracurricular activities were associated with social-emotional skills, whereas sports activities were not. It was also found that the physical activity index was not related to socioemotional factors, except in self-awareness and in a negative way. It is necessary to analyse the quality of the extracurricular programmes offered and the training of the professionals in charge of their development. It also seems important to take into account the gender perspective in competence work, increasing self-management in girls and relationship management in boys.

Accelerometer-Measured Physical Activity and Sedentary Behavior Levels and Patterns in Female Sixth Graders: The CReActivity Project

Regular physical activity (PA) and low levels of sedentary behavior (SB) have positive health effects on young people. Adolescent girls of low socioeconomic background represent a high-risk group with regard to physical inactivity and SB. In this study, accelerometer-measured levels of PA and SB of female sixth graders attending lower secondary schools in Germany are presented, patterns of PA and SB throughout the day are described and differences between weekdays and weekend days are analyzed. Data of 425 students of the CReActivity project were analyzed. Sampling and processing of accelerometer data followed recent recommendations, which had not been applied to data of a German-speaking sample before. The WHO recommendation of daily 60 min moderate-to-vigorous PA was fulfilled by 90.4% of the girls on weekdays and by 57.4% on weekend days. The significant weekday-weekend differences were mainly associated with active commuting to and from school. Students engaged in SB for more than 8 h on weekdays and for over 7 h on weekend days. The results suggest a strong need for interventions increasing PA and reducing SB, especially during school hours and on weekends. Furthermore, a comparison with methods and results of previous studies highlights the need to follow recent criteria in accelerometer data sampling and processing to ensure an accurate and valid differentiation between PA-related risk groups and non-risk groups.

A Systematic Review of Children's Physical Activity Patterns: Concept, Operational Definitions, Instruments, Statistical Analyses, and Health Implications

Despite the widespread use of the expression “physical activity pattern” (PAP), there apparently is no general consensus regarding its definition. This systematic review aimed to examine available research focussing on (1) definitions of PAP, (2) instruments/techniques used to describe PAP, (3) statistical approaches used to analyse PAP, and (4) implications of PAP on children’s health. A systematic review of the available literature was done to identify studies published up to October 2019, and 76 studies were eligible. None of the studies presented a formal definition of PAP; a wide range of instruments were used to investigate children’s PAP, and most of the revised studies did not explicitly present a formal statistical model to define PAP. Twenty-four papers purported to examine associations between PAP and health indicators. The review highlights no consensus on a clear PAP definition whatever the instrument used to capture it, and we did not find any agreement regarding how best to analyse PAP. We suggest that PAP should be used when targeting the investigation of similarities/dissimilarities, as well as stabilities and/or changes in children’s PA at an intra-personal level. In sum, PAP should be used to best describe individual streams of behaviours, and not exclusively PA levels/intensities.

Associations Between Parent Self-Reported and Accelerometer-Measured Physical Activity and Sedentary Time in Children: Ecological Momentary Assessment Study

BACKGROUND

Retrospective self-report questionnaires are the most common method for assessing physical activity (PA) and sedentary behavior (SB) in children when the use of objective assessment methods (eg, accelerometry) is cost prohibitive. However, self-report measures have limitations (eg, recall bias). The use of real-time, mobile ecological momentary assessment (EMA) has been proposed to address these shortcomings. The study findings will provide useful information for researchers interested in using EMA surveys for measuring PA and SB in children, particularly when reported by a parent or caregiver.

OBJECTIVE

This study aimed to examine the associations between the parent's EMA report of their child's PA and SB and accelerometer-measured sedentary time (ST), light-intensity PA (LPA), and moderate-to-vigorous-intensity PA (MVPA) and to examine if these associations differed by day of week, sex, and season.

METHODS

A total of 140 parent-child dyads (mean child age 6.4 years, SD 0.8; n=66 girls; n=21 African American; n=24 American Indian; n=25 Hispanic/Latino; n=24 Hmong; n=22 Somali; and n=24 white) participated in this study. During an 8-day period, parents reported child PA and SB via multiple daily signal contingent EMA surveys, and children wore a hip-mounted accelerometer to objectively measure ST, LPA, and MVPA. Accelerometer data was matched to the time period occurring before parent EMA-report of child PA and SB. Generalized estimating equations with interaction-term analyses were performed to determine whether the relationship between parent-EMA report of child PA and SB and accelerometer-measured ST and LPA and MVPA outcomes differed by day of the week, sex and season.

RESULTS

The parent's EMA report of their child's PA and SB was strongly associated with accelerometer-measured ST, LPA, and MVPA. The parent's EMA report of their child's PA was stronger during the weekend than on weekdays for accelerometer-measured ST (P≤.001) and LPA (P<.001). For the parent's EMA report of their child's SB, strong associations were observed with accelerometer-measured ST (P<.001), LPA (P=.005), and MVPA (P=.008). The findings related to sex-interaction terms indicated that the association between the parent-reported child's PA via EMA and the accelerometer-measured MVPA was stronger for boys than girls (P=.02). The association between the parent's EMA report of their child's PA and SB and accelerometer-measured ST and PA was similar across seasons in this sample (all P values >.31).

CONCLUSIONS

When the use of accelerometry-based methods is not feasible and in contexts where the parent is able to spend more proximate time observing the child's PA and SB, the parent's EMA report might be a superior method for measuring PA and SB in young children relative to self-report, given the EMA's strong associations with accelerometer-measured PA and ST.

Bidirectional Associations between Objective Physical Activity and Sleep Patterns in Spanish School Children

Physical activity (PA) and sleep contribute to better children’s health. Nonetheless, the bidirectional relationship between both of these health-related factors is unclear when using objective measures. The aims of this study were (1) to describe the PA (light PA and moderate-to-vigorous PA (MVPA) and sleep (duration, latency, and efficiency) patterns of children and compare them with recommendations, and (2) to analyze the bidirectional association between PA levels and sleep patterns in 470 Spanish children according to sex (average age of 8.4 (0.4) years, 51.9% boys). A tri-axial accelerometer and sleep logs were used to measure PA (light PA and MVPA) and sleep patterns (duration, latency, and efficiency) in the children for seven consecutive days. Linear mixed models were conducted to analyze the bidirectional association (PA → sleep and sleep → PA) adjusted for the child, the sex, the school, and the day of observation. The results showed that, overall, the children did not meet the sleep duration recommendations per day. Regarding the bidirectional association, increased light PA and MVPA during the day was related to decreased sleep duration but an improvement in sleep efficiency that night. However, sleep duration and sleep efficiency were only related negatively and positively to light PA the following day, respectively. Regarding sex, light PA was associated with decreased sleep duration in both sexes, although the average value was lower in boys. In addition, light PA was also related only to an improvement in sleep efficiency the same night in both sexes, with girls generally having more efficient sleep. More studies in a representative sample of children that use objective measures to corroborate these results are needed.

Physical Activity and Commuting to School in Spanish Nine-Year-Old Children: Differences by Gender and by Geographical Environment

Children’s health status is related to their physical activity levels. Active commuting is associated with higher physical activity and reduced risk of all-cause mortality, cardiovascular disease incidence, and diabetes. The objective of this research was to study the levels of physical activity and the commuting to school (active vs. passive) in Spanish nine-year-old children, analyzing the differences by gender and by the geographical environment where they live (rural or urban environment). Accelerometry was used for the measurement of physical activity: Sedentary time (min/day), vigorous physical activity (min/day), moderate to vigorous physical activity (min/day), intensity (counts/min), steps (number). The questionnaire of the European Youth Heart Study (EYHS) was used to determine the geographical environment (city/urban, residential area/outside city, rural/village) and the modes of transport (active: Walking and bicycle, passive: Car, motorcycle, public transport). A total of 455 Spanish nine-year-old children (247 girls and 208 boys) belonging to the EYHS participated in this study. The results showed that boys were significantly more physically active than girls (p ≤ 0.001). Results also showed that active commuting to school was positively correlated with the levels of physical activity (r = 0.324, p ≤ 0.001). The geographical environment influenced the way in which children went to school, being active commuting to school significantly (p ≤ 0.001) less frequent in those children who lived in a rural environment (22.4%) than in those who lived in the city (57.1%) or in a residential area (62.7%). As active commuting to school means increasing levels of physical activity in both sexes, strategies should be implemented in order to encourage active commuting to schools, contributing at the same time to better health and sustainability of future generations.

Are primary school children attending full-day school still engaged in sports clubs?

PURPOSE

Schools and organized sports both offer great chances to promote physical activity among children. Full-day schools particularly allow for extensive participation in extra-curricular physical activities. However, due to time reasons, full-day schools may also prevent children from engagement in organized sports outside school. There is only little national and international research addressing the possible competition of full-day schools and providers of organized sports outside school and the potential effects on children's physical activity behavior. In Germany's educational system, a transformation towards more full-day schools is currently taking place. The existence of both, half-day and full-day schools, gave occasion to the following research question: Do students attending half-day and full-day school differ with respect to a) sports club membership rate and b) weekly amount of sports club training?

METHODS

Data were collected in eleven German primary schools. Selected schools offered both half-day and full-day (minimum three days/week with at least seven hours) care. 372 students' data (grades 1-4; N = 153 half-day, N = 219 full-day; 47.4% male, 8.8±1.2y) were eligible for analyses. We assessed sports club membership and weekly training duration via questionnaire. Statistical analyses included Chi-square and Mann-Whitney-U-Tests.

RESULTS

83% of half-day school students and 67% of full-day school students were sports club members (χ2(1) = 12.31, p<.001). Weekly duration of training in sports clubs among sports club members (N = 266) also differed between the groups (mdn = 150 min in half-day, mdn = 120 min in full-day school students; z = -2.37, p = .018). Additional analyses stratified for age and gender showed similar results.

CONCLUSION

Primary school students attending full-day schools engage less in organized sports outside school than half-day school students, regardless of age and gender. Future studies should examine if the detected lower engagement in sports club physical activity is compensated by physical activities in other settings such as school or non-organized leisure time.

Association Between Self-Reported and Objective Activity Levels by Demographic Factors: Ecological Momentary Assessment Study in Children

Background

To address the limitations of the retrospective self-reports of activity, such as its susceptibility to recall bias, researchers have shifted toward collecting real-time activity data on mobile devices via ecological momentary assessment (EMA). Although EMA is becoming increasingly common, it is not known how EMA self-reports of physical activity and sedentary behaviors relate to the objective measures of activity or whether there are factors that may influence the strength of association between these two measures. Understanding the relationship between EMA and accelerometry can optimize future instrument selection in studies assessing activity and health outcomes.

Objective

The aim of this study was to examine the associations between EMA-reported sports or exercise using the accelerometer-measured moderate-to-vigorous physical activity (MVPA) and EMA-reported TV, videos, or video games with the accelerometer-measured sedentary time (ST) in children during matched 2-h windows and test potential moderators.

Methods

Children (N=192; mean age 9.6 years; 94/192, 49.0% male; 104/192, 54.2% Hispanic; and 73/192, 38.0% overweight or obese) wore an accelerometer and completed up to 7 EMA prompts per day for 8 days during nonschool time, reporting on past 2-h sports or exercise and TV, videos, or video games. Multilevel models were used to assess the relationship between the accelerometer-measured ST and EMA-reported TV, videos, or video games. Given the zero-inflated distribution of MVPA, 2-part models were used assess the relationship between the accelerometer-measured MVPA and EMA-reported sports or exercise.

Results

EMA-reported TV, videos, or video games were associated with a greater accelerometer-measured ST (beta=7.3, 95% CI 5.5 to 9.0, P<.001). This relationship was stronger in boys (beta=9.9, 95% CI 7.2 to 12.6, P<.001) than that in girls (beta=4.9, 95% CI 2.6 to 7.2, P≤.001). EMA-reported sports or exercise was associated with a greater accelerometer-measured MVPA (zero portion P<.001; positive portion P<.001). This relationship was stronger on weekends, in older children, and in non-Hispanic children (zero portion all P values<.001; positive portion all P values<.001).

Conclusions

EMA reports highly relate to accelerometer measures. However, the differences in the strength of association depending on various demographic characteristics suggest that future research should use both EMA and accelerometers to measure activity to collect complementary activity data.

The Link Between Nutrition and Physical Activity in Increasing Academic Achievement

BACKGROUND

Research demonstrates a link between decreased cognitive function in overweight school-aged children and improved cognitive function among students with high fitness levels and children engaging in regular physical activity (PA). The purpose of this study was to examine whether regular PA and proper nutrition together had a significant effect on academic achievement.

METHODS

Using the seventh wave of the Early Childhood Longitudinal Study, Kindergarten Class 1998-99 (ECLS-K) dataset, linear regression analysis with a Jackknife resampling correction was conducted to analyze the relationship among nutrition, PA, and academic achievement, while controlling for socioeconomic status, age, and sex. A nonactive, unhealthy nutrition group and a physically active, healthy nutrition group were compared on standardized tests of academic achievement.

RESULTS

Findings indicated that PA levels and proper nutrition significantly predicted achievement scores. Thus, the active, healthy nutrition group scored higher on reading, math, and science standardized achievement tests scores.

CONCLUSIONS

There is a strong connection between healthy nutrition and adequate PA, and the average performance within the population. Thus, results from this study suggest a supporting relationship between students' health and academic achievement. Findings also provide implications for school and district policy changes.

Understanding differences between summer vs. school obesogenic behaviors of children: the structured days hypothesis

BACKGROUND

Although the scientific community has acknowledged modest improvements can be made to weight status and obesogenic behaviors (i.e., physical activity, sedentary/screen time, diet, and sleep) during the school year, studies suggests improvements are erased as elementary-age children are released to summer vacation. Emerging evidence shows children return to school after summer vacation displaying accelerated weight gain compared to the weight gained occurring during the school year. Understanding how summer days differ from when children are in school is, therefore, essential.

DISCUSSION

There is limited evidence on the etiology of accelerated weight gain during summer, with few studies comparing obesogenic behaviors on the same children during school and summer. For many children, summer days may be analogous to weekend days throughout the school year. Weekend days are often limited in consistent and formal structure, and thus differ from school days where segmented, pre-planned, restrictive, and compulsory components exist that shape obesogenic behaviors. The authors hypothesize that obesogenic behaviors are beneficially regulated when children are exposed to a structured day (i.e., school weekday) compared to what commonly occurs during summer. This is referred to as the 'Structured Days Hypothesis' (SDH). To illustrate how the SDH operates, this study examines empirical data that compares weekend day (less-structured) versus weekday (structured) obesogenic behaviors in U.S. elementary school-aged children. From 190 studies, 155 (~80%) demonstrate elementary-aged children's obesogenic behaviors are more unfavorable during weekend days compared to weekdays.

CONCLUSION

In light of the SDH, consistent evidence demonstrates the structured environment of weekdays may help to protect children by regulating obesogenic behaviors, most likely through compulsory physical activity opportunities, restricting caloric intake, reducing screen time occasions, and regulating sleep schedules. Summer is emerging as the critical period where childhood obesity prevention efforts need to be focused. The SDH can help researchers understand the drivers of obesogenic behaviors during summer and lead to innovative intervention development.

Changes in Physical Activity in the School, Afterschool, and Evening Periods During the Transition From Elementary to Middle School

BACKGROUND

We examined longitudinal changes in children's physical activity during the school day, afterschool, and evening across fifth, sixth, and seventh grades.

METHODS

The analytical sample included children who had valid accelerometer data in fifth grade and at least one other time-point, and provided complete sociodemographic information (N = 768, 751, and 612 for the 3 time-periods studied). Accelerometer-derived total physical activity (TPA) and moderate-to-vigorous physical activity (MVPA) were expressed in minutes per hour for the school day (∼7:45 am to 3:30 pm), afterschool (∼2:25 to 6:00 pm), and evening (6:00 to 10:00 pm) periods. We used growth curve analyses to examine changes in TPA and MVPA.

RESULTS

School day TPA and MVPA declined significantly; we observed a greater decrease from fifth to sixth grades than from sixth to seventh grades. Afterschool TPA declined significantly, but MVPA increased significantly among girls and remained stable for boys. Evening TPA decreased significantly and MVPA declined significantly in girls and remained stable among boys.

CONCLUSIONS

To inform the development of effective intervention strategies, research should focus on examining factors associated with the decline in physical activity during the transition from elementary to middle school, particularly during the hours when children are in school.

Parents' Social Status and Children's Daily Physical Activity: The Role of Familial Socialization and Support

Physical activity is a health relevant factor, particularly in affluent societies where overweight and obesity are increasingly prevalent, even among children. Understanding the development of physical activity patterns in childhood is thus an important issue for health promotion. Following socialization theory, this study describes and explains differences in objectively measured moderate-to-vigorous physical activity (MVPA) in a socially and ethnically mixed sample of 6- to 11-year-old children in Germany. MVPA levels were objectively measured with accelerometers over the course of six consecutive days (Wednesday to Monday). Parents' attitudes and practices as well as the family's socio-economic status (SES) were assessed from the parents via questionnaires. Results indicate that MVPA levels of children vary with gender, but not with age and ethnicity. Moreover, parental SES, parental support for the child's sports activities, parents' own sport activities and the parents' belief in sports' capacities to foster personality development, character building and social integration significantly predict the MVPA level of children. It is concluded that interventions to promote MVPA among children need to take family interactions and lifestyles into account and should address families in socio-economically underprivileged areas.

Is physical education an effective way to increase physical activity in children with lower cardiorespiratory fitness?

Several findings revealed the importance of accruing moderate and vigorous physical activity (MVPA) to improve health. Physical education (PE) may play an important role on promoting children's MVPA. However, it remains unknown whether PE might be effective when increasing physical activity (PA) levels in children with lower cardiorespiratory fitness (CRF). Therefore, the aim of this study was to assess children's PA during PE and during days with and without PE with a special focus on CRF status. One hundred and fifty Spanish children and adolescents from 3rd to 12th grade were recruited. PA levels were assessed with GT3X accelerometers. Peak oxygen uptake (VO_2peak ) was estimated using a portable breath by breath Metamax 3B. Participants were classified as healthy aerobic fitness (HAF) and unhealthy aerobic fitness (UHAF) according to standardized cut-off point criteria. During PE, students with HAF accrued more MVPA than those with UHAF (8.7 vs 5.7 min/session; P ≤ 0.001). MVPA was higher on PE days than days without for both UHAF (50.0 vs 42.7 min/day; P ≤ 0.05) and HAF students (56.9 vs 49.4 min/day; P ≤ 0.05). Although less active during PE, students with lower CRF accumulated more MVPA and total PA on PE days than days without PE. An increase in PE days might be a smart policy to raise the recommended PA levels, regardless of CRF status.

Assessment of Eating Habits and Physical Activity among Spanish Adolescents. The "Cooking and Active Leisure" TAS Program

Worldwide obesity has more than doubled in the last forty years. Even more worrying is the fact that the number of overweight and obese children and adolescents has considerably increased. Socioeconomic development, as well as educational, agricultural and marketing policies have significantly changed dietary and physical activity habits among the youngest, who are thus susceptible to develop chronic and disabling diseases such as diabetes, some cancers and cardiovascular disorders. Adolescence is a critical age, in which the adoption of healthy habits may have dramatic effects on the health state in adulthood. For this reason, prompt interventions are urgently required to prevent the onset of obesity in this time of life. In this regard, the CAL-TAS program from Alicia Foundation was born to combat obesity and promote healthy lifestyles in Spanish adolescents. A total of 2519 students, aged 13–14 years, from 79 schools distributed all over the 17 autonomous communities in Spain were asked to report through the CAL-TAS platform their food intake and physical activity over one week. The body mass index, the consumption of food and beverages, the intake of macronutrients and micronutrients, and the values obtained from the PAQ-A questionnaire, which evaluated physical activity, were analyzed. Twenty percent of the participants were overweight or obese. In general, adolescents did not or poorly respected the recommendations provided by the Spanish Society of Community Nutrition. For example, in more than half of the subjects, the ingestion of fruits and beverages was less than recommended, whereas the consumption of meat, baked goods and fried foods was excessive. Moreover, adolescents with higher body mass index also presented worse eating habits and more inactivity. In conclusion, Spanish adolescents present low adherence to recommendations provided by the Spanish Society of Community Nutrition (SENC) and by the World Health Organization. In order to prevent obesity-related disorders, effective educational programmes have to be designed. Indeed, adolescents and their families should be aware that the early adoption of healthy dietary habits and of a correct physical activity may strongly improve their future quality of life.

Objectively measured physical activity levels and sedentary time in 7-9-year-old Estonian schoolchildren: independent associations with body composition parameters

BACKGROUND

Sufficient daily physical activity (PA) is necessary for physical, social and mental health benefits during growth. Most of the available data on children is based on subjective reports, while only limited data on objective PA and sedentary levels is available for primary school children. Increased PA is also an important health indicator of body composition parameters, especially body adiposity indices. The aim of the present study was to determine objectively the amount of daily PA levels at different intensities and sedentary time in normal-weight (NW) and overweight (OW) 7-9-year-old boys and girls, and to find associations between objectively measured PA levels and sedentary time with different body composition values.

METHODS

Two hundred and seventy eight (142 boys and 136 girls) primary school children aged 7.9 ± 0.7 years participated in this study. Objective PA intensity and sedentary levels were measured over 7 days by accelerometry. Indices of total fat mass (body fat %, sum of skinfolds), fat distribution (waist-to-height ratio) and muscular component (fat free mass [FFM]) were calculated from measured anthropometric parameters.

RESULTS

There were no differences (p > 0.05) in PA intensity levels and sedentary time between boys and girls as well as between NW and OW children. About 11 % of children met the current guidelines of at least 60 min per day of moderate-to-vigorous PA (MVPA). Sedentary time was positively and negatively associated (p < 0.05) with all body fat and FFM values, respectively. Moderate and vigorous PA along with MVPA were negatively and positively associated (p < 0.05) with all body fat and FFM indices, respectively.

CONCLUSIONS

The results of present study showed that about 11 % of primary school children were engaged in PA of at least 60 min of MVPA daily. While MVPA is negatively associated with fat mass indices and positively associated with FFM regardless of different confounders, sedentary time is negatively related to FFM and positively with fat mass values after adjusting for several confounders. These results suggest that higher MVPA level and lower sedentary time level are important in maintaining and developing healthy body composition in primary school children during growth.

Gender and grade differences in objectively measured physical activity and sedentary behavior patterns among Japanese children and adolescents: a cross-sectional study

Background

Physical activity levels in childhood have decreased, making the promotion of children’s physical activity an important issue. The present study examined gender and grade differences in objectively measured sedentary behavior, physical activity, and physical activity guideline attainment among Japanese children and adolescents.

Methods

In total, 329 boys and 362 girls age 3–15 years completed the survey. School grade, gender, height, and weight were collected by questionnaires and physical activity objectively measured using an accelerometer (Lifecorder Suzuken Co.). Physical activity level (in MET) was classified as sedentary (<1.5), light (≥1.5 to <3), moderate (≥3 to <6), or vigorous (≥6). Continuous zero accelerometer counts for ≥20 min were censored and a valid accelerometry study required at least 3 days (2 weekdays and 1 weekend day) with > 600 min/day total wear time. Two-way analysis of covariance and logistic regression analyses, adjusted for weight status and accelerometer wear time, were used to examine gender and grade differences in physical activity variables and the likelihood of physical activity guideline attainment by gender and grade level.

Results

Participants were sedentary 441.4 (SD, 140.1) min/day or 53.7 % of the average daily accelerometer wear time of 811.2 (118.7) min, engaged in light physical activity 307.1 (70.0) min or 38.4 % of wear time, moderate physical activity 34.6 (14.8) min (4.3 %), vigorous physical activity 28.3 (19.1) min (3.6 %), and took 12462.6 (4452.5) steps/day. Boys were more physically active and took more steps/day than girls. Students in higher grades were less active than those in lower grades. Boys were significantly more likely to meet physical activity guidelines than girls (OR: 2.07, 95 % CI: 1.45–2.96). Preschoolers (6.66, 4.01–11.06), lower-grade elementary school students (17.11, 8.80–33.27), and higher-grade elementary school students (7.49, 4.71–11.92) were more likely to meet guidelines than junior high school students.

Conclusions

Boys and lower-grade students engaged in more physical activity and were more likely to attain guidelines than girls and higher-grade students. These findings highlight the need for effective and sustainable strategies to promote physical activity in Japanese school children.

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.

Gender differences on effectiveness of a school-based physical activity intervention for reducing cardiometabolic risk: a cluster randomized trial

Background

Studies that have examined the impact of a physical activity intervention on cardiometabolic risk factors have yielded conflicting results. The objective of this study was to assess the impact of a standardized physical activity program on adiposity and cardiometabolic risk factors in schoolchildren.

Methods

Cluster randomized trial study of 712 schoolchildren, 8–10 years, from 20 public schools in the Province of Cuenca, Spain. The intervention (MOVI-2) consisted of play-based and non-competitive activities. MOVI-2 was conducted during two 90-minute sessions on weekdays and one 150-minute session on Saturday mornings every week between September 2010 and May 2011. We measured changes in adiposity (overweight/obesity prevalence, body mass index [BMI], triceps skinfold thickness [TST], body fat %, fat-free mass, waist circumference) and other cardiometabolic risk factors (LDL-cholesterol, triglycerides/HDL-cholesterol ratio, insulin, C-reactive protein and blood pressure). The analyses used mixed regression models to adjust for baseline covariates under cluster randomization.

Results

Among girls, we found a reduction of adiposity in intervention versus control schools, with a decrease in TST (−1.1 mm; 95% confidence interval [CI] -2.3 to −0.7), body fat % (−0.9%; 95% CI −1.3 to −0.4), waist circumference (−2.7 cm; 95% CI −4.5 to −0.9), and an increase in fat-free mass (0.3 kg; 95% CI 0.01 to 0.6). The intervention also led to lower serum LDL-cholesterol and insulin levels. Among boys, a reduction in waist circumference (−1.4 cm; 95% CI −2.6 to −0.1; P = 0.03), and an increase in fat-free mass (0.5 kg; 95% CI 0.2 to 0.9; P = 0.003) was associated with the intervention versus control schools. The prevalence of overweight/obesity or underweight, BMI, and other cardiometabolic risk factors was not modified by the intervention. No important adverse events were registered.

Conclusions

An extracurricular intervention of non-competitive physical activity during an academic year, targeting all schoolchildren regardless of body weight, is a safe and effective measure to reduce adiposity in both genders and to improve cardiometabolic risk profile in girls.

Trial registration

Clinical trials NCT01277224.

Electronic supplementary material

The online version of this article (doi:10.1186/s12966-014-0154-4) contains supplementary material, which is available to authorized users.

Physical fitness in Spanish schoolchildren aged 6-12 years: reference values of the battery EUROFIT and associated cardiovascular risk

BACKGROUND

Physical fitness is considered an important indicator of health in children. The aims of this study were to (1) provide sex- and age-specific EUROFIT battery levels of fitness in Spanish children; (2) compare Spanish children's fitness levels with those of children from other countries; and (3) determine the percentage of Spanish children with cardiovascular risk associated with low cardiorespiratory fitness (CRF).

METHODS

Physical fitness was assessed using the EUROFIT tests in 1725 children, aged 6 to 12, from Castilla-La Mancha, Spain. We derived specific values for physical fitness using LMS method. FITNESSGRAM 2010 criteria were used to estimate the percentage of children with cardiovascular risk associated with low CRF.

RESULTS

Boys scored higher in all the physical fitness tests, except for the flexibility test. Physical fitness improved as age increased, except for flexibility, which worsened in boys, and VO2max, which decreased in both sexes. The prevalence of boys and girls with cardiovascular risk associated to low CRF was 13% and 26%, respectively.

CONCLUSIONS

Specific fitness test scores for children and adolescents can represent the fitness status of schoolchildren accurately. Schools need to make efforts to improve the fitness level of the schoolchildren to prevent cardiovascular risk.

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.

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.

Socio-demographic and behavioral risk factors associated with the high prevalence of overweight and obesity in Portuguese children

OBJECTIVES

Childhood obesity is a public health concern in Portugal. Socio-demographic and behavioral factors are highly associated with obesity but are not clearly understood. This article aims to update the prevalence of overweight and obesity in Portuguese children and to explore the influence and risks of socio-demographic factors and behavioral factors.

METHODS

A cross-sectional study of Portuguese children aged 3-10 years from all 18 mainland districts took place between March 2009 and January 2010. The sample was composed by 17,136 children, 3-10 years of age (8,455 boys; 8,681 girls). Height, weight, and other anthropometric measurements were obtained by trained technicians. Body mass index (BMI) was calculated along with other anthropometric variables. Data analyses took place between April and September 2012. The overweight/obesity classification was established by age-and sex-specific BMI cut-off points as defined by the International obesity task force (IOTF). Parents completed questionnaires about socio-demographic and behavioral characteristics of the family.

RESULTS

Almost 28% of the Portuguese children were overweight or obese (19.7% overweight; 8.2% obese). Prevalence was greater in girls than in boys. Logistic regression models found that the odds of childhood obesity were significantly affected by biological, socio-demographic, and behavioral factors.

CONCLUSIONS

The protective factors against childhood overweight/obesity in this sample of Portuguese children are: (i) being male; (ii) having been breastfeed; (iii) having been born from mothers who did not smoke during pregnancy; (iv) engaging in little sedentary behaviors (TV, PC, and playing electronic games); (iv) performing at least 1 h of moderate physical activity every day; and (v) having parents with higher educational levels who also have their BMI within the healthy ranges.

Patterns of physical activity outside of school time among Japanese junior high school students

BACKGROUND

Physical activity is beneficial for adolescent health. The physical activity patterns of Japanese adolescents are relatively unknown. Therefore, this study aimed to describe the current patterns of physical activity and to identify sex and grade differences among them.

METHODS

The participants comprised 714 Japanese adolescents aged 12 to 15 years old (boys N = 372, girls N = 342) from a public junior high school in Okayama, Japan. Physical activity at school, outside of school after hours, and during lunch recess as well as the total leisure time in a usual week was assessed with a 5-item questionnaire. To assess the differences in the physical activity patterns by sex and grade, independent t tests and analysis of variance (ANOVA) were conducted, respectively.

RESULTS

Boys spent significantly more time in physical activity both inside and outside of school settings than girls (p < .05). Higher grade students were significantly less active than lower grade students (p < .05). Furthermore, the physical activity patterns across the grades differed between settings (at school, outside of school during the after-school period, lunchtime recess, and at home).

CONCLUSION

To increase physical activity levels among Japanese adolescents, implementation of after-school programs or environmental modifications developed within the school setting could be effective strategies.

Weekday and weekend patterns of physical activity and sedentary time among Liverpool and Madrid youth

Levels of physical inactivity and sedentary behaviour among English and Spanish youth are high and vary within different regions of each country. Little though is known about these during specific periods of the day. The purpose of this study was to describe physical activity (PA) and sedentary time during segments of the day and week, and compare these critical contexts between youth in the Liverpool and Madrid areas of England and Spain, respectively. PA was objectively assessed in 235 Liverpool- and 241 Madrid youth (aged 10-14 years) who wore accelerometers for seven consecutive days. Minutes of sedentary time, moderate PA, vigorous PA and moderate-to-vigorous physical activity (MVPA) were calculated for weekdays, weekend days, school time, non-school time and after-school. Between-country differences were analysed using analysis of covariance (ANCOVA). Madrid youth spent significantly more time in sedentary activities than their Liverpool counterparts. Madrid youth engaged in more minutes of moderate intensity physical activity (MPA) than Liverpool youth during weekdays, school time and non-school time (P<0.01). Liverpool children recorded more time in vigorous physical activity (VPA) than Madrid peers during week days and weekend days (P<0.01) and during school time and after-school periods (P<0.01). The MVPA was significantly higher among Madrid youth during non-school time (P<0.01). Around 25% of all youth achieved recommended levels of MVPA. Low levels of MVPA and systematic differences in sedentary time, MPA and VPA exist between Liverpool and Madrid youth. Interventions targeted at the least-active children during weekends, after-school and non-school periods within the cultural contexts common to each city are required.

Level of physical activity among children and adolescents in Europe: a review of physical activity assessed objectively by accelerometry

This study explored the proportion of European youth who are sufficiently active according to physical activity (PA) recommendations, based exclusively on objective assessment through accelerometers. A systematic electronic search of studies published up to March 2012 was conducted. PubMed was used to identify accelerometry-assessed PA studies that involved European youth. Within the 131 European studies, only 35 clearly reported the proportion of youth meeting the PA recommendations. Different thresholds lying between 1000 and 4000 counts/min (cpm) were used to define moderate-to-vigorous PA (MVPA). Overall, up to 100% of youth may be sufficiently active when using a threshold of approximately >1000-1500 cpm. With the most cited cut-off point (i.e. >2000 cpm), up to 87% of European youth might be considered physically active with reference to the current recommendations. Alternatively, with a cut-off point >3000 cpm, no more than 3-5% of them appeared to achieve these recommendations. The large discrepancy in outcomes released by accelerometer data is mainly due to the variety of cut-off points for MVPA among youth, hindering the definition of a clear goal towards PA promotion in Europe. Standardization of methods is urgently required.

Recommended levels of physical activity to avoid adiposity in Spanish children

What is already known about this subject There is an association between adiposity levels and physical activity guidelines for adolescents. Achieving physical activity recommendations helps adolescents to prevent obesity status. What this study adds This paper presents an association between physical activity levels and obesity status. This paper supports physical activity recommendations to avoid children's obesity levels. This paper emphasizes vigorous physical activity for this matter.

BACKGROUND

There is no information about physical activity (PA) recommendations to avoid children's obesity levels and how much of vigorous PA (VPA) is included into the '60 minutes of MVPA 5 days a week' recommendation for children.

OBJECTIVE

The aim of this study was to examine the association between PA and adiposity in children and to examine whether the current PA guidelines are associated with a low risk of having excess of body fat in children, with special focus on sex differences, and PA intensity.

METHODS

A sample of 439 Spanish children aged 8-10 years from the European Youth Heart Study participated in the study. The variables measured were anthropometric characteristics (height, weight, body mass index [BMI], skin-folds and waist circumference) and PA was measured during 6 consecutive days using the GT1M accelerometer.

RESULTS

Receiver operating characteristic analysis showed significant cut-off points associated with non-overweight: 45 min d(-1) of VPA and 67 min d(-1) of moderate-to-vigorous physical activity (MVPA) (using BMI categories); and non-fat: 41 min d(-1) of VPA and 67 min d(-1) of MVPA (using percentage of body fat) and 38 min d(-1) of VPA and 47 min d(-1) of MVPA (using waist circumference categories) for boys. For girls, the optimal cut-offs of moderate-to-vigorous activity and MVPA associated with non-overweight were 24 and 57 min d(-1) , respectively (BMI). Boys who did not meet 67 min in MVPA had an increased risk of being overweight + obese and overfat + obese (odds ratio [OR] = 2.48, 95% confidence interval [CI] = 1.36, 4.53, and OR = 2.56, 95% CI = 1.12, 5.82).

CONCLUSIONS

The findings support current PA recommendations (60 min d(-1) of MVPA) to avoid excess of body fat in Spanish children. However, VPA appears to be an important component for the prevention of obesity, and our findings suggest that PA recommendations should specify the dose of VPA required for optimal health. Therefore, public health PA recommendations should incorporate specifically a greater dose of VPA into the total amount of MVPA in 8- to 10-year-old boys.

[Weight status, dietary habits and physical activity among 6-12 year-old children in Castile-La Mancha]

INTRODUCTION

Childhood obesity is a multifactorial disease, in which unhealthy dietary patterns and sedentary lifestyles play a decisive role. The aim of this study was to assess the weight status, dietary habits and physical activity in Castile-La Mancha children.

SUBJECTS AND METHODS

A cross-sectional study was conducted on 3061 children 6-12 years-old who were participating in the programme, "Alimenta su salud". Anthropometric measurements, food consumption frequency, dietary habits and physical activity were assessed by a questionnaire, including gender, age and geographical influences.

RESULTS

The prevalence of subjects with excess weight-for-height was 24.0% and obesity was 14.3%, with geographical differences. Girls more often have mid-morning snacks, consume more supplements, and reported to be less active than boys. Special diets and sports activities were lower in children aged 6-9 years as compared to the 10-12 years old group. The intake of vegetables and fruit is low, while there is overconsumption of sausages, pastries, salted snacks, sweets and fast food, with some differences by age group.

CONCLUSIONS

One out of four children is overweight or obese in this population. Children do not meet recommendations for fruit and vegetables and there is a high consumption of foods associated with obesity risk. Physical inactivity was more prevalent during the weekends, and among girls.

Can we modulate physical activity in children? No

Intuition tells us that physical activity is central to weight reduction in obese children. Evidence, on the other hand, suggests that increases in physical activity are difficult to achieve in the short term, and may not be possible in the long term. One explanation could be an 'activitystat', a feedback loop in the child's brain that controls physical activity according to a set point. This brief article, which argues that it may not be possible to modulate the activity of children, reviews the principles of feedback control as they apply to physical activity, discusses evidence for its central control, and demonstrates how a physical activity control loop might operate to defend the set point. Studies restricted to objective measurement suggest that the physical activity of children varies in a systematic, rather than random manner. It varies little from environment to environment, from year to year or from place to place. Where children undertake more activity at one time of day, they appear to compensate at another. Systematic variation of this kind implies control, and the control of physical activity appears to lie with the child, not with his environment. Perturbation (temporary change in response to disturbance) during short-term physical activity interventions may be mistaken for modulation (permanent change in set point), a fundamentally different response. Perturbation lasts no longer than the disturbance that causes it, and there is little evidence that interventions raise activity long term, if at all.

Associations between activity-related behaviours and standardized BMI among Australian adolescents

OBJECTIVES

To examine the relationships between physical activity, sedentary behaviour and body mass index (BMI) among a sample of Australian adolescents.

METHODS

Anthropometric, demographic and behavioural data were collected from students (n=3040 mean age 14.6, 44% female) from 12 secondary schools in South West Victoria, Australia (response rate=48.6%). The appropriate descriptive, univariate and regression analysis were used to examine the strength of the associations between physical activity, sedentary behaviour and odds of overweight or obese and the effect of interaction between physical activity and sedentary behaviour on odds of overweight and obese.

RESULTS

Males were more likely to be active during the school day than females and had higher median hours of screen time per school day. Physical activity during the school day was associated with higher standardized BMI (BMI-z) among males. Higher levels of activity after school were associated with lower BMI-z for males and females. For both males and females the odds of overweight or obese were higher among the least active. An interaction was observed for females whereby the prevalence of overweight and obesity among the most physically active was lowest for the least sedentary and highest for the most sedentary.

CONCLUSIONS

The relationships between physical activity, sedentary behaviour and BMI-z were complex. Interventions to reduce BMI through increasing physical activity or decreasing sedentary behaviour need to consider the complex inter-relationships between these variables and moderating factors such as age, sex and socio economic status in their design and interpretation.