Effects of the inclusion of physical activity in secondary education academic classes on educational indicators and health markers: rationale and methods of the ACTIVE CLASS study.

Background: Increasing physical activity (PA) levels and reducing sedentary behaviors in children and adolescents is a need, especially in schools. Active breaks and physically active learning are examples of two emerging methodologies that have been shown to be effective in increasing PA levels and additionally produce improvements in children's educational markers. However, the evidence in adolescents is very limited. This paper presents the design, measurements, and interventions implemented in the ACTIVE CLASS study, whose objectives are: (i) evaluate the effects of two interventions on PA levels, sedentary time, health-related physical fitness academic indicators, cognition, and markers of psychological health among secondary education students; (ii) evaluate teachers' and students' experiences about the implementation of these the two school-based PA intervention. Methods: A randomized controlled study is conducted with a total of 292 students aged 12-14 years old from six schools (7th and 8th grade) in Spain (three in Cadiz and three in Caceres). One school from each study provinces is randomly assigned to either the active break intervention group, the physically active learning intervention group, or the control group. The interventions have a duration of 16 weeks. Nine main measurement categories are assessed: PA and sedentary time, health-related physical fitness, academic indicators, cognition, psychological health, motivational variables, dietary patterns, sociodemographic characteristics, as well as qualitative information through semi-structured individual interviews and focus groups. Three independent measurements of evaluation are distinguished: pre-intervention, post-intervention (week 16) and retention measurement (4 weeks after the intervention). For quantitative variables, descriptive, correlational, regression and repeated measures ANOVA will be applied. Discussion: To the best of our knowledge, the ACTIVE CLASS study is the first of its kind in Spain to evaluate the effects of incorporating active breaks and physically active learning in secondary education. In addition, this project provides important information on the effects of two school-based PA intervention arms on educational variables and health markers in adolescents. This will provide valuable and innovative training to the educational community, enabling them to implement teaching methodologies that have the potential to enhance academic performance and improve the quality of life for their students. Clinical trial registration: clinicaltrials.gov, NCT05891054.

Criterion-Related Validity of Field-Based Methods and Equations for Body Composition Estimation in Adults: A Systematic Review.

PURPOSE OF REVIEW: Overweight and obesity are associated to health prognosis. Therefore, body composition assessment is an important health outcome, especially in adult population. We analyzed the criterion-related validity of existing field-based methods and equations for body composition estimation in adults aged 19-64 years. RECENT FINDINGS: One hundred studies met inclusion criteria. The field-based methods, waist circumference (WC), body adiposity index (BAI), and body mass index (BMI) are valid to indicate body adiposity. Likewise, several equations, including the classical Durnin/Womersley equation, Jackson/Pollock equation (males), and Jackson, Pollock, and Ward equation (females), are valid to estimate total body fat mass or body fat percentage. Anthropometric field methods can provide a simple, quick, and easy informative indicators of adiposity in adults. Classical equations, such as Durnin/Womersley equation, Jackson/Pollock equation, and Jackson, Pollock, and Ward equation, are still valid to estimate total body fat mass or body fat percentage in adult population. When choosing estimation equations, specific population characteristics, such as age, weight status, or race ethnicity, should be taken into account. (Trial Registration: Registered on PROSPERO (CRD42020194272)).

A cross-sectional association of physical fitness with positive and negative affect in children and adolescents: the up & down study.

BACKGROUND: Affect and physical fitness play an important role in psychological and physical health; however, the association between those variables in youth remains unknown. The aim of the present study was to examine the influence of physical fitness on positive and negative affect in Spanish children and adolescents. METHOD: Healthy young Spanish people (n = 1,490) were recruited for the present study: 542 children (n = 272 girls; mean age 9.6 years) and 948 adolescents (n = 454 girls; mean age 14.1 years) with complete baseline data on health-related fitness tests (20 m shuttle run test, 4 × 10 m test, muscular fitness index, and physical fitness index), and positive and negative affect (Positive and Negative Affect Schedule). RESULTS: Higher performance on physical fitness components was associated with positive affect (ß = -0.176-0.118, all P < 0.05). There was no association between all physical fitness components and negative affect (ß = -0.100-0.15, all P > 0.05). There were differences on positive affect between the lowest and the highest quartile of the physical fitness index in boys (P = 0.037, Cohen's d 0.60) and girls (P = 0.004, Cohen's d = 0.69), and between the lowest and the highest quartile of muscular fitness index in girls (P < 0.001, Cohen's d = 0.76). CONCLUSIONS: Promoting physical activity during the school years, including strength exercises to increase muscular fitness, could improve positive affect levels and thus psychological health.

Trends of Sedentary Time and Domain-Specific Sedentary Behavior in Spanish Schoolchildren.

Purpose: To examine the temporal trends of accelerometer-based total daily sedentary time (ST) and self-reported domain-specific sedentary behavior (SB) on weekdays and weekends in Spanish children. Method: A total of 560 (50.53% girls) children (4th graders) in 2011/12 from 23 Spanish schools and 462 (48.70% girls) children (4th graders) in 2017/18 from 19 schools across Cadiz participated. Hip-worn accelerometers and questionnaires were used to assess total daily ST and self-reported time in SB modalities, respectively. Results: The objectively measured total daily ST tended to increase in boys on weekdays and weekends. Time spent watching television (TV) decreased during the week and weekend days, while time surfing on the internet increased on weekdays and weekends. Playing video-games increased in boys during the weekends. The trend to increase the time spent on educational activities with a computer during the weekdays and weekends was accompanied by a reduction of the same activities without using a computer. There was a trend to increase reading for fun, talking on the phone and total time in other SB, on weekdays and weekends in boys and girls. Conclusion(s): Spanish boys tended to increase objectively measured total daily ST. Moreover, SB modalities have changed in recent years in children, replacing TV viewing by computer use for both educational and non-educational purposes, as well as by the use of smartphones or other sedentary activities that does not imply the presence of a screen. These findings highlight the need to promote interventions to decrease total daily ST and reduce SB activities.

Physical Fitness and Self-Rated Health in Children and Adolescents: Cross-Sectional and Longitudinal Study.

Self-rated health (SRH) is an independent determinant for all-cause mortality. We aimed to examine the independent and combined associations of components of physical fitness with SRH at baseline (cross-sectional) and two years later (longitudinal) in children and adolescents. Spanish youth (N = 1378) aged 8 to 17.9 years participated at baseline. The dropout rate at 2-year follow-up was 19.5% (n = 270). Participants were categorized as either children (8 to 11.9 years age) or adolescents (12 to 17.9 years age). The ALPHA health- related fitness test battery for youth was used to assess physical fitness, and SRH was measured by a single-item question. Cumulative link, ANOVA and ANCOVA models were fitted to analyze the data. Cardiorespiratory fitness, relative upper body isometric muscular strength, muscular strength score, and global physical fitness were positively associated with SRH in children (OR, 1.048; 95% CI, 1.020-1.076; OR, 18.921; 95% CI, 3.47-104.355; OR, 1.213; 95% CI, 1.117-1.319, and OR, 1.170; 95% CI, 1.081-1.266, respectively; all p < 0.001) and adolescents (OR, 1.057; 95% CI, 1.037-1.076; OR, 5.707; 95% CI, 1.122-29.205; OR, 1.169; 95% CI, 1.070-1.278, and OR, 1.154 95% CI, 1.100-1.210, respectively; all p < 0.001); and motor fitness was positively associated with SRH only in adolescents at baseline (OR, 1.192; 95% CI, 1.066-1.309; p < 0.01). Cardiorespiratory fitness and global physical fitness were positively associated with SRH in children two years later (OR, 1.056; 95% CI, 1.023-1.091; p < 0.001; and OR, 1.082; 95% CI, 1.031-1.136; p < 0.01; respectively). Only cardiorespiratory fitness was independently associated with SRH in children and adolescents at baseline (OR, 1.059; 95% CI, 1.029-1.090; and OR, 1.073; 95% CI, 1.050-1.097, respectively; both p < 0.001) and two years later (OR, 1.075; 95% CI, 1.040-1.112; p < 0.001; and OR, 1.043; 95% CI, 1.014-1.074; p < 0.01, respectively). A high level of cardiorespiratory fitness at baseline or maintaining high levels of cardiorespiratory fitness from the baseline to 2-year follow-up were associated with a higher level of SRH at 2-year follow-up in children (p < 0.01) and adolescents (p < 0.05). These findings emphasize the importance of cardiorespiratory fitness as strong predictor of present and future SRH in youth. Intervention programs to enhance cardiorespiratory fitness level of the youth population are urgently needed for present and future youth's health.

Changes in the school and non-school sedentary time in youth: The UP&DOWN longitudinal study.

The aims of this study were (i) to examine the sedentary time (ST) during different time periods [i.e., weekend, out-of-school weekdays hours, school hours, recess, physical education classes (PEC)] in children and adolescents; (ii) to identify 2-year longitudinal changes in the ST for these periods; and (iii) to examine if ST at baseline is associated with ST 2 years later. This was a 2-year follow-up study with 826 (51.9% boys) children and 678 (50.7% boys) adolescents. Accelerometers were used to assess ST. Students spent more than 60% of their weekend, out-of-school hours and school hours in ST. During these periods, girls and adolescents were more sedentary than boys and children, respectively (p < 0.05). Over 2-year follow-up, ST increased during the weekend, out-of-school hours, school hours and recess in all subgroups studied (p < 0.001). ST during PEC declined 2% per year in children (p < 0.001) but it increased in adolescents (p < 0.05). ST during the periods analysed at baseline was lowly associated with ST during these periods 2 years later (intraclass correlations from <0.001 to 0.364). Interventions in these settings may be adequate if the intention is to avoid ST increase in students.

Does modality matter? A latent profile and transition analysis of sedentary behaviours among school-aged youth: The UP&DOWN study.

The aims of this study were to identify profiles of sedentary behaviour (SB) patterns, based on leisure-time self-reported SB modalities (screen, educative, social, and relaxing) and to evaluate changes in these profiles over 2 years among Spanish youth aged 8-18 years. Latent profile analysis (LPA), a data-driven analytic approach, was used to identify groups of boys and girls (n = 1553; 48% girls; mean±SD age: 12.56 ± 2.49 y) with distinct SB profiles using the SB modalities (time/d) as input variables. Latent transition analysis, an extension of LPA that uses longitudinal data, was used to analyse 2-year changes in these profiles. At baseline, four and three SB profiles were found among boys (labelled: screen, educative, social, and relaxing) and girls (labelled: screen/social, educative, and relaxing), respectively. Overall, more girls (range: 48%-67%) had the same profile over time, than boys (40%-52%). Participants with a screen or relaxing SB profile at baseline were more likely to have an educative profile after 2 years. Youth with a social and an educative SB profile at baseline were more likely to transition to profiles characterized by higher screen and social SB, respectively. Using a novel and person-centered approach, this study identified gender-specific SB profiles that were moderately stable over time.

How socio-demographic and familiar circumstances are associated with total and domain-specific sedentary behaviour in youth? The UP&DOWN study.

Objective: The aims of the present study were to analyze the associations between the socio-demographic and familiar circumstances with: (i) the total leisure-time sedentary behavior (SB) assessed by accelerometry, and (ii) the domain-specific leisure-time SB (i.e., screen-based, educational-based, social-based, and other-based SB), in a sample of Spanish youth. Method: The sample consisted of 1,543 youth (12.02 ± 2.51 years) included in the UP&DOWN study. SB was evaluated by accelerometry and questionnaire. Nationality, location of school, type of school, socio-economic status, parental educational level, parental occupation status, family structure, number of siblings and position among siblings were self-reported by participants or their parents. Linear mixed models, including school and city as random effects, were performed. Results: Several associations were found; however, socio-demographic and family circumstances differently associated with SB according to the domain-specific SB, the sex and the type of day. For example, participants with a father holding a high-skilled occupation spent lower time in screen-based SB during weekdays; and mother occupation status of high qualification was related to higher educational-based SB in boys. Having three or more sibling was associated with lower total SB in boys, while having an obese mother was related to higher screen-based SB on weekends both in boys and girls. Conclusions: Socio-demographic and familiar circumstances are associated with SB in young people, so future interventions should consider multiple and sex-specific factors for reduce SB of young people, focusing especially on youth with a low number of siblings and with parents holding low-skilled employments.

Dance participation and academic performance in youth girls

Dance is a predominant type of physical activity among girls. Dance characteristics imply skills associated to health-related physical fitness, as well as others such as learning and memory, mental representation, imagination and creativity, which are related to cognitive development. Although dance has been shown to influence physical health among youth girls, whether dance may influence academic performance and cognition in youth remains to be elucidated. The objective of this work was to examine the association between participation in dance and academic performance in youth girls.

Physical Activity Coparticipation and Independent Mobility as Correlates of Objectively Measured Nonschool Physical Activity in Different School Grades. The UP&DOWN Study.

BACKGROUND: The aim was to investigate the association of (i) parental, sibling, and friend coparticipation in physical activity (PA); and (ii) independent mobility (IM) for walking, cycling, and taking public transport with objectively measured nonschool PA on week- and weekend days in different school grades. METHODS: A total of 1376 Spanish youngsters (50.8% boys; mean age 11.96 ± 2.48 years) participated in the study. Participants reported the frequency of their parental, sibling, and best friend coparticipation in PA with them and their IM for walking, cycling, and taking public transport. PA was objectively measured by accelerometry. RESULTS: Coparticipation in PA and IM were more frequently related to nonschool PA among adolescents than among children. Friend coparticipation in PA was positively associated with higher levels of nonschool PA in adolescents. IM for walking and IM for cycling in adolescents were related to nonschool PA on weekdays. CONCLUSIONS: Our results highlight the need for age-focused interventions and the integration of family and friends to promote PA in youth.

Adherence to the Mediterranean diet and academic performance in youth: the UP&DOWN study.

PURPOSE: To examine the association between adherence to the Mediterranean diet and academic performance in children and adolescents. METHODS: This is a cross-sectional study conducted with 1371 youth aged 12.04 ± 2.50 years (685 girls) in Spain during 2011-2012. Adherence to the Mediterranean diet was assessed using the KIDMED index (Mediterranean Diet Quality Index in children and adolescents), which includes 16 questions on specific dietary patterns. Levels of adherence were classified into three groups: poor adherence (0-3), average adherence (4-7), and good adherence (8-12). Academic performance was assessed through school records using four indicators: math, language, an average of math and language, and grade point average score. RESULTS: Adherence to the Mediterranean diet was related to academic performance (ß ranging from 0.107 to 0.148; all P < 0.001) after adjusting for confounders. The group of good adherence to the Mediterranean diet had significantly higher scores in all of the academic indicators compared with the poor group (ranging from +0.429 to 0.464; all P ≤ 0.001); as well as the group of average adherence to the Mediterranean diet had significantly higher scores in all of the academic indicators compared with the poor group (ranging from +0.292 to 0.344; all P ≤ 0.06). There were no differences between the groups of good and average adherence to the Mediterranean diet. CONCLUSIONS: Adherence to the Mediterranean diet may have a beneficial influence on academic performance in youth. Importantly, the benefits of adherence to the Mediterranean diet on academic performance may be stronger as youth adhered to the optimal Mediterranean diet levels.

Independent and combined influence of the components of physical fitness on academic performance in youth.

OBJECTIVE: To examine the independent and combined associations of the components of physical fitness with academic performance among youths. STUDY DESIGN: This cross-sectional study included a total of 2038 youths (989 girls) aged 6-18 years. Cardiorespiratory capacity was measured using the 20-m shuttle run test. Motor ability was assessed with the 4×10-m shuttle run test of speed of movement, agility, and coordination. A muscular strength z-score was computed based on handgrip strength and standing long jump distance. Academic performance was assessed through school records using 4 indicators: Mathematics, Language, an average of Mathematics and Language, and grade point average score. RESULTS: Cardiorespiratory capacity and motor ability were independently associated with all academic variables in youth, even after adjustment for fitness and fatness indicators (all P≤.001), whereas muscular strength was not associated with academic performance independent of the other 2 physical fitness components. In addition, the combined adverse effects of low cardiorespiratory capacity and motor ability on academic performance were observed across the risk groups (P for trend<.001). CONCLUSION: Cardiorespiratory capacity and motor ability, both independently and combined, may have a beneficial influence on academic performance in youth.

Associations of muscular fitness with psychological positive health, health complaints, and health risk behaviors in Spanish children and adolescents.

We examined the association of muscular fitness with psychological positive health, health complaints, and health risk behaviors in 690 (n = 322 girls) Spanish children and adolescents (6-17.9 years old). Lower body muscular strength was assessed with the standing long jump test, and upper-body muscular strength was assessed with the throw basketball test. A muscular fitness index was computed by means of standardized measures of both tests. Psychosocial positive health, health complaints, and health risk behaviors were self-reported using the items of the Health Behavior in School-aged Children questionnaire. Psychological positive health indicators included the following: perceived health status, life satisfaction, quality of family relationships, quality of peer relationships, and academic performance. We computed a health complaints index from 8 registered symptoms: headache, stomach ache, backache, feeling low, irritability or bad temper, feeling nervous, difficulties getting to sleep, and feeling dizzy. The health risk behavior indicators studied included tobacco use, alcohol use, and getting drunk. Children and adolescents with low muscular fitness (below the mean) had a higher odds ratio (OR) of reporting fair (vs. excellent) perceived health status, low life satisfaction (vs. very happy), low quality of family relationships (vs. very good), and low academic performance (vs. very good). Likewise, children and adolescents having low muscular fitness had a significantly higher OR of reporting smoking tobacco sometimes (vs. never), drinking alcohol sometimes (vs. never), and getting drunk sometimes (vs. never). The results of this study suggest a link between muscular fitness and psychological positive health and health risk behavior indicators in children and adolescents.

Cardiorespiratory fitness and fatness are associated with health complaints and health risk behaviors in youth.

BACKGROUND: We examined the association of cardiorespiratory fitness and fatness with health complaints and health risk behaviors in 691 (323 girls) Spanish children aged 6 to 17.9. METHODS: Health complaints and health risk behaviors were self-reported using items of the Health Behavior in School-aged Children questionnaire. Weight and height were measured and body mass index was computed. Cardiorespiratory fitness was measured by the 20-m shuttle-run test, and youth categorized as fit/unfit. RESULTS: Unfit youth were more likely to report health complaints sometime (OR: 2.556, 95% CI: 1.299-5.031; and OR: 1.997, 95% CI: 1.162-3.433, respectively) and health risk behaviors such as drinking alcohol sometime (OR: 5.142, 95% CI: 1.214-21.783; and OR: 2.413, 95% CI: 1.484-3.923) than their fit counterparts. Overweight-obese youth were more likely to report health complaints (OR: 1.732, 95% CI: 1.019-2.945; and OR: 1.983, 95% CI: 1.083-3.629, respectively). The analysis of the combined influence of fitness and fatness revealed that fit youth had lower health complaints index than the fat-unfit and unfat-unfit groups (all P < .05). CONCLUSIONS: Low fitness and overweight-obesity increased the risk of having health complaints in youth, yet high levels of cardiorespiratory fitness might overcome deleterious effects of overweight-obesity on health complaints.

Positive health, cardiorespiratory fitness and fatness in children and adolescents.

BACKGROUND: Positive health is likely a buffer against physical and mental illness. Positive health may explain some of the health benefits associated with increasing cardiorespiratory fitness and decreasing fatness in youth. We examined the association of cardiorespiratory fitness and fatness with positive health indicators in 684 (365 boys and 319 girls) Spanish children aged 6-17.9 years. METHODS: Positive health indicators were self-reported using items of the Health Behavior in School-aged Children questionnaire. The study health indicators were: perceived health status, life satisfaction, quality of family relationships, quality of peer relationships and academic performance. Weight and height were measured and body mass index was computed. We also measured triceps and calf skinfolds thickness and body fat percentage was estimated. Cardiorespiratory fitness was measured by the 20 m shuttle-run test. RESULTS: Cardiorespiratory fitness was positively associated with life satisfaction in children and adolescents. Fatness was inversely associated with perceived health status in children and adolescents, whereas fatness was inversely associated with life satisfaction, quality of family relationships and academic performance only in children. CONCLUSION: These findings suggest a link between cardiorespiratory fitness and fatness and positive health indicators, suggesting that improving both fitness and fatness could exert a favourable effect on positive health during childhood and adolescence.