Fitness, body composition, and metabolic risk scores in children and adolescents: the UP&DOWN study.

We aimed to analyse the longitudinal association between physical fitness (PF) and body composition (BC) with a metabolic risk score (Met4) in children and adolescents and to elucidate whether the association between PF and Met4 differs when using relativized or absolute fitness variables. A total of 188 children (86 females) and 195 adolescents (97 females) were included. Cardiorespiratory fitness (CRF) was determined by the 20-m shuttle run test, and muscular fitness (MF) was determined by hand grip and standing long jump tests. Height and weight were measured, and the body mass index (Kg/m2) was calculated. Triceps and subscapular skinfolds were assessed to compute body fat percentage. Met4 was computed from systolic blood pressure, triglycerides, high-density lipoprotein cholesterol, and glucose levels. Relative CRF was longitudinally and negatively associated with Met4 in female children (ß = -0.031, p = 0.025), while absolute CRF was positively associated with Met4 in male children and adolescents (ß = 0.000, p < 0.05). Relative upper and lower-body MF were longitudinally and negatively associated with Met4 in female adolescents (ß = -1.347, ß = -0.005, p < 0.05), while absolute lower-body MF was positively associated with Met4 in male children (ß = 0.000, p = 0.019). BC was longitudinally and positively associated with Met4 in male children (ß-ranging from 0.011 to 0.055, all p < 0.05) and male adolescents (ß-ranging from 0.011 to 0.046, all p < 0.05).  Conclusion: BC is more strongly associated with Met4 than PF in children and adolescents. An optimal body weight status should be considered the main objective of health-promoting programs at childhood and adolescence. Furthermore, the way of expressing the fitness variables determines the direction of the association with Met4. What is Known: • Physical fitness is an important health indicator in children and adolescents, with great amount of previous evidence supporting the preventive role of maintaining optimal levels of both cardiorespiratory and muscular fitness for future cardiometabolic issues. What is New: • The way of reporting physical fitness variables can affect the associations between physical fitness features and cardiometabolic outcomes. Since body composition variables have a great impact on both physical fitness and cardiometabolic health, relativizing physical fitness performance by body composition could lead to erroneous conclusions.

Results From Spain's 2022 Para Report Cards on Physical Activity of Children and Adolescents With Disabilities.

This report aims to provide a better understanding of physical activity (PA) and related factors among Spanish children and adolescents living with disabilities. The 10 indicators used for the Global Matrix on Para Report Cards of children and adolescents living with disabilities were evaluated based on the best available data in Spain. An analysis of strengths, weaknesses, opportunities, and threats based on data provision was drafted by three experts and critically reviewed by the authorship team to provide a national perspective for each evaluated indicator. Government was the indicator with the highest grade (C+), followed by Sedentary Behaviors (C-), School (D), Overall PA (D-), and Community & Environment (F). The remaining indicators received an incomplete grade. There were low levels of PA in Spanish children and adolescents living with disabilities. Yet, opportunities to improve the current surveillance of PA among this population exist.

Bidirectional longitudinal associations of fatness with physical fitness in adolescents with Down syndrome. The UP&DOWN Longitudinal study.

BACKGROUND: The aim of this study was to examine the bidirectional longitudinal associations of several markers of fatness and physical fitness in adolescents with Down syndrome. METHODS: This study comprised a total of 111 adolescents (41 females), aged from 11 to 20 years with complete data at the baseline. We had a drop-out of <10% from the baseline to the 2-year follow-up. The ALPHA health-related fitness test battery for youth was used. RESULTS: Our results show that all fatness variables at the baseline were associated with a 2-year change in cardiorespiratory fitness (ß ranging from -0.32 to -0.38; all p < .05), but not with muscular and motor fitness (p > .05). However, no associations were found between physical fitness components as predictors and fatness indicators (p > .05). CONCLUSIONS: Results suggest that reducing fatness during adolescence might represent a modifiable factor to improve cardiorespiratory fitness at the 2-year follow-up, but not vice versa since associations were not bidirectional.

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.

[Family environment, physical activity and sedentarism in preadolescents with childhood obesity: ANOBAS case-control study]. / Ambiente familiar, actividad física y sedentarismo en preadolescentes con obesidad infantil: estudio ANOBAS de casos-controles.

OBJECTIVE: The aim of this study is to compare the levels of physical activity and sedentary behaviours in children with obesity and normal weight through accelerometer measures, and analyze the family environment related to physical activity. DESIGN: Case-control study. LOCATION: A health center and colleges of the Community of Madrid. PARTICIPANTS: A total of 50 obese children between 8 and 12 years of age (P > 97) and their mothers were matched by age, sex and socioeconomic status of their parents (1: 1) with 50 children with normopeso (GN; P < 85). MAIN MEASUREMENTS: Physical activity levels were measured by accelerometer (ActiGraph GT3X), levels of physical activity of the primary caregiver were measured through physical activity questionnaire (IPAQ) and the environment in relation to the physical activity was measured by the Home Environment Scale (HES-S). RESULTS: The group GO showed less vigorous physical activity than their peers in the GN group. Vigorous physical activity in the GO group was associated with modeling and parental policies regarding physical activity. A multiple regression analysis revealed that 21% of the variance of weight status of children was explained by sex, vigorous physical activity and maternal body mass index. CONCLUSIONS: The levels of vigorous physical activity and the family environment differ between children with obesity and normal weight. Therefore, it is important to continue working on the awareness of illness and the promotion of healthy habits from Primary Care and the school and institutional context.

A longitudinal perspective of eating disorder risk in immigrant and Spanish native adolescents: The longitudinal up & down study.

OBJECTIVES: Previous research has postulated immigrant status as a relevant factor influencing eating disorder (ED) risk in adolescents. The present study assesses differences by sex in ED risk between Spanish native and immigrant adolescent populations residing in Spain and analyzes longitudinal differences in ED risk between immigrant and native adolescents over 2-year follow-up. METHOD: The study sample was 981 adolescents aged 11-19 years at baseline. ED risk was evaluated using the Spanish version of the SCOFF Questionnaire. Logistic regression was used to value associations between country of origin and ED risk prevalence by sex, as well as changes in ED risk at 2-year follow-up. RESULTS: Immigrant adolescent girls and boys presented greater ED risk than their Spanish counterparts. Prospective analyses showed that immigrant boys presented greater likelihood of acquiring ED risk over 2 years compared to Spanish adolescent boys. CONCLUSION: Immigrant adolescent populations, particularly boys, seem to be vulnerable to ED. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Association between Clustering of Lifestyle Behaviors and Health-Related Physical Fitness in Youth: The UP&DOWN Study.

OBJECTIVES: To examine clustering of lifestyle behaviors in Spanish children and adolescents based on screen time, nonscreen sedentary time, moderate-to-vigorous physical activity, Mediterranean diet quality, and sleep time, and to analyze its association with health-related physical fitness. STUDY DESIGN: The sample consisted of 1197 children and adolescents (597 boys), aged 8-18 years, included in the baseline cohort of the UP&DOWN study. Moderate-to-vigorous physical activity was assessed by accelerometry. Screen time, nonscreen sedentary time, Mediterranean diet quality, and sleep time were self-reported by participants. Health-related physical fitness was measured following the Assessing Levels of Physical Activity battery for youth. A 2-stage cluster analysis was performed based on the 5 lifestyle behaviors. Associations of clusters with fatness and physical fitness were analyzed by 1-way ANCOVA. RESULTS: Five lifestyle clusters were identified: (1) active (n = 171), (2) sedentary nonscreen sedentary time-high diet quality (n = 250), (3) inactive-high sleep time (n = 249 [20.8%]), (4) sedentary nonscreen sedentary time-low diet quality (n = 273), and (5) sedentary screen time-low sleep time (n = 254). Cluster 1 was the healthiest profile in relation to health-related physical fitness in both boys and girls. In boys, cluster 3 had the worst fatness and fitness levels, whereas in girls the worst scores were found in clusters 4 and 5. CONCLUSIONS: Clustering of different lifestyle behaviors was identified and differences in health-related physical fitness were found among clusters, which suggests that special attention should be given to sedentary behaviors in girls and physical activity in boys when developing childhood health prevention strategies focusing on lifestyles patterns.

Independent and combined associations of physical fitness components with inflammatory biomarkers in children and adolescents.

BACKGROUND: We aimed to examine the independent and combined associations of cardiorespiratory fitness, muscular fitness, and motor ability with single and clustered inflammatory biomarkers in children and adolescents. METHODS: This study included 503 children and adolescents. Cardiorespiratory fitness, upper- and lower-muscular fitness, and motor ability were assessed using field-based tests. Fasting blood samples were obtained to determine the levels of a set of inflammatory biomarkers. Global physical fitness and clustered inflammatory biomarker scores were computed. Associations between physical fitness and inflammatory biomarkers were analyzed through linear regression. Differences in inflammatory biomarker levels between physical fitness tertiles were tested. RESULTS: Global physical fitness was inversely associated with single and clustered inflammatory biomarkers in children (p < 0.05); and with C-reactive protein, complement factor C4, leptin, and clustered inflammatory biomarkers in adolescents (p < 0.025). Cardiorespiratory fitness and upper-muscular fitness were negatively and independently associated with several single and clustered inflammatory biomarkers in children and adolescents (p < 0.05). Differences were found between the lowest and the highest tertiles of global physical fitness in clustered inflammatory biomarker levels (p < 0.010). CONCLUSION: Physical fitness was negatively associated with single and clustered inflammatory biomarkers, independently of body mass index. Increasing physical fitness levels in youth might contribute to reduce the cardiovascular risk.

Definitions, measurement and prevalence of sedentary behaviour in adults with intellectual disabilities - A systematic review.

Supporting positive change in lifestyle behaviours is a priority in tackling the health inequalities experienced by adults with intellectual disabilities. In this systematic review, we examine the evidence on the definition, measurement and epidemiology of sedentary behaviour of adults with intellectual disabilities. A systematic literature search of PUBMED, EMBASE, MEDLINE and Google Scholar was performed to identify studies published from 1990 up to October 2015. Nineteen papers met the criteria for inclusion in the systematic review. Many researchers do not distinguish between insufficient physical activity and sedentary behaviour. None of the studies reported the reliability and validity of the methods used to measure sedentary behaviour. Sedentary time, assessed objectively, ranged from 522 to 643min/day: higher than in adults without intellectual disabilities. This first-ever review of sedentary behaviour and intellectual disabilities found that at present the evidence base is weak. Studies calibrating accelerometer data with criterion measures for sedentary behaviour are needed to determine specific cut-off points to measure sedentary behaviour in adults with intellectual disabilities. Researchers should also examine the reliability and validity of using proxy-report questionnaires to measure sedentary behaviour in this group. A better understanding of sedentary behaviour will inform the design of novel interventions to change lifestyle behaviours of adults with intellectual disabilities.

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.

Correlates of sedentary behaviour in youths with Down syndrome: the UP&DOWN study.

The aim of this study was to identify potential correlates of sedentary time and television (TV) viewing time in youth with Down syndrome (DS). A total of 98 adolescents with DS (63 males) aged 11-20 years old participated in this study. Total sedentary time was measured using accelerometers, while total TV viewing time and potential correlates were measured using proxy-report questionnaire. Analyses of covariance and a stepwise multiple linear regression were performed to examine correlates of total sedentary time and total TV viewing time. Different potential correlates were associated with total sedentary time (mother age, mother TV viewing time, perceived benefits of physical activity, birth order and having nearby shops in the neighbourhood) and total TV viewing time (father TV viewing time, TV viewing time with parents, family dietary habits during watching TV and weekend days time indoor). The identification of correlates associated with sedentary behaviour, principally those considered modifiable such as social and environmental factors, may contribute to development strategies to decrease sedentary behaviour in adolescents with DS and consequently promote a healthier lifestyle.

The role of physical activity in the association between disability and mortality among US older adults: a nationwide prospective cohort study.

To examine whether physical activity can mitigate the mortality risk associated with disability in activities of daily living and instrumental activities in daily living among older adults. This analysis comprised 177,360 US participants (104,556 women), aged ≥ 60 years, with valid data from the 1997 through 2018 waves of the US National Health Interview Survey. Participants reported the frequency and duration of leisure-time PA, and their disabilities in activities of daily living and instrumental activities in daily living. Mortality data were obtained from the National Death Index. Over a mean (SD) follow-up of 8.02 (5.43) years, 66,694 deaths occurred from all-cause, 22,673 from cardiovascular disease, and 13,845 from cancer. Among people with disability in activities in daily living, those reaching physical activity recommendations had 25%, 24% and 33% lower risk of all-cause mortality, cardiovascular diseases, and cancer death, respectively, compared with those who do not meet physical activity recommendations. Values were 23%, 22% and 24% for those with disability in instrumental activities in daily living. Risk reductions associated with reaching the recommended physical activity ranged 16% to 29% for people without disability. Combining disability type and compliance with physical activity, individuals with disability in activities of daily living or instrumental activities in daily living who meet the recommended physical activity had moderately higher mortality than those without disability who did not achieve the recommended physical activity. Compliance with physical activity recommendations can partially mitigate excess mortality resulting from disability in activities in daily living or instrumental activities in daily living in older adults.

Reliability of the ALPHA health-related fitness test battery in adolescents with Down syndrome.

The Assessing Levels of Physical Activity (ALPHA) health-related fitness test battery is a set of reliable, valid, and feasible tests to assess health-related physical fitness in children and in adolescents. The aim of this study was to examine the reliability of this battery in adolescents with Down syndrome (DS). The extended ALPHA health-related fitness test battery was performed twice within 1 month in 17 apparently healthy adolescents, aged 12-18 years, with DS who had an intelligence quotient ≥ 35. Intraclass correlation coefficient (ICC) was used to determinate test-retest reliability, and nonparametric Wilcoxon signed rank test was used to compare mean differences between measurements. With the exception of subscapular skinfold test, which obtained a moderate agreement (ICC = 0.64), all tests had a very high reliability: the 20-m shuttle-run test (ICC = 0.86), the right handgrip strength test (ICC = 0.86), the left handgrip strength test (ICC = 0.86), the standing broad jump test (ICC = 0.85), body mass index (ICC = 0.95), waist circumference (ICC = 0.98), triceps skinfold (ICC = 0.85), and the 4 × 10-m shuttle-run test (ICC = 0.92). There were no significant differences (all p > 0.05) in any of the tests. The ALPHA health-related fitness battery is reliable for measuring health-related components of fitness in adolescents with DS.

Time measurement validity and reliability of the 4 × 10-m shuttle run test in adult population: The ADULT-FIT project.

OBJECTIVES: The purpose of this study was to analyze the time measurement validity and reliability (between raters and test-retest) of the 4 × 10-m shuttle run test to assess motor fitness in adults, according to gender, age, and physical activity levels. DESIGN: Cross-sectional. A total of 230 adults (86 women) aged 18-64 years participated in the study. METHODS: The time taken to complete the 4 × 10-m shuttle run test was recorded simultaneously by a trained and an untrained rater (inter-rater reliability) and by photoelectric cells (time measurement validity). 48-72 h later, the test was repeated under the same conditions (test-retest reliability). RESULTS: The systematic error for trained rater vs. photocell was close to zero (0.0125, p < 0.01), with an effect size of 0.006; and for both, untrained rater vs. photocell and trained rater vs. untrained rater was ∼0.2 s (p < 0.001) with an effect size of 0.09. For the test-retest reliability, the systematic error was 0.05 s (p < 0.001), with an effect size of 0.26, the intraclass correlation coefficient was 0.998 and the coefficient of variation reported a variability of 0.73 %. Results were not influenced by gender and age, while these improved for active vs. non-active participants. CONCLUSIONS: Findings indicate that measurements with trained raters are a valid and reliable method for assessing the 4 × 10-m shuttle run test in adults. It is highly recommended that raters be trained to minimize the measurement error.

Prospective Associations of Physical Activity and Health-Related Physical Fitness in Adolescents with Down Syndrome: The UP&DOWN Longitudinal Study.

(1) Background: Numerous studies have focused on examining the association between PA levels and health-related physical fitness components in children or adolescents without disabilities. However, research on the association between PA and health-related physical fitness in adolescents with DS (Down syndrome) is limited, and most of the previous studies have been developed with a cross-sectional perspective. Therefore, the aim of the present study was to assess the prospective association of accelerometer-based PA at baseline with health-related physical fitness at a 2-year follow-up in a relatively large sample of adolescents with DS from the UP&DOWN study. (2) Methods: A total of 92 adolescents with DS (58 males) between 11 and 20 years old with full data were eligible from an initial sample of 110 participants. Fitness was assessed by the ALPHA health-related fitness test battery for youth, and physical activity was assessed by Actigraph accelerometers. (3) Results: The high tertile of total PA was related to decreased motor (Beta [95% CI] = -1.46 [-2.88; -0.05]) and cardiorespiratory fitness (Beta [95% CI] = -2.22 [-4.42; 0.02]) in adolescents with DS. (4) Conclusions: In adolescents with DS, (i) PA level was not prospectively associated with muscular fitness and (ii) high levels of total PA at the baseline were inversely associated with motor and cardiorespiratory fitness at the 2-year follow-up. For comparative purposes, these relationships were also examined in a subsample of adolescents without DS.

Criterion-Related Validity of Field-Based Fitness Tests in Adults: A Systematic Review.

We comprehensively assessed the criterion-related validity of existing field-based fitness tests used to indicate adult health (19-64 years, with no known pathologies). The medical electronic databases MEDLINE (via PubMed) and Web of Science (all databases) were screened for studies published up to July 2020. Each original study's methodological quality was classified as high, low and very low, according to the number of participants, the description of the study population, statistical analysis and systematic reviews which were appraised via the AMSTAR rating scale. Three evidence levels were constructed (strong, moderate and limited evidence) according to the number of studies and the consistency of the findings. We identified 101 original studies (50 of high quality) and five systematic reviews examining the criterion-related validity of field-based fitness tests in adults. Strong evidence indicated that the 20 m shuttle run, 1.5-mile, 12 min run/walk, YMCA step, 2 km walk and 6 min walk test are valid for estimating cardiorespiratory fitness; the handgrip strength test is valid for assessing hand maximal isometric strength; and the Biering-Sørensen test to evaluate the endurance strength of hip and back muscles; however, the sit-and reach test, and its different versions, and the toe-to-touch test are not valid for assessing hamstring and lower back flexibility. We found moderate evidence supporting that the 20 m square shuttle run test is a valid test for estimating cardiorespiratory fitness. Other field-based fitness tests presented limited evidence, mainly due to few studies. We developed an evidence-based proposal of the most valid field-based fitness tests in healthy adults aged 19-64 years old.

A longitudinal gender perspective of well-being and health in spanish youth: the UP&DOWN study.

Previous studies have observed a link between gender and well-being and health in young populations. The purpose of this research was twofold: (1) to analyse the cross-sectional relationship between gender status with well-being indicators and self-perceived health in adolescents at baseline and at 2-year follow-up and (2) to evaluate the prospective associations between gender at baseline and well-being indicators/self-perceived health assessed at 2-year follow-up. Well-being was measured using the KIDSCREEN-10 questionnaire (as a measure of health-related quality of life (HR-QoL)), the Children's Hope Scale and the Positive and Negative Affect Schedule. Health status of the adolescents was assessed using self-perceived health. Multilevel mixed-effects linear/logistic regression models were carried out to assess the associations between gender status and well-being and health of a sample of 1590 Spanish adolescents. Adolescent girls were shown to have lower HR-QoL scores and higher negative affect scores, and had a higher risk of reporting poor health than boys, in both cross-sectional and longitudinal analyses. Adolescent girls seem to be more vulnerable to poorer well-being and self-reported health than boys. When looking at hedonic and eudemonic well-being separately, longitudinal differential evolution of boys and girls seems to indicate greater deterioration of hedonic well-being among girls as compared to boys. Overall, gender may have a relevant impact on mental and physical health during adolescence.

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.

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 Body Composition and Physical Fitness in Adolescents with Down Syndrome: The UP&DOWN Longitudinal Study.

Background: Adolescents with Down syndrome (DS) demonstrate higher values of body composition and lower levels of physical fitness when compared with their peers with typically developing (TD) or their peers with intellectual disability but without DS. Objective: To examine, during a 2-year period, changes in indicators of body composition and physical fitness components in TD adolescents and adolescents with DS. Methods: Hundred adolescents with DS (64 males) aged 11-20 years old were matched by sex to 163 TD adolescents (108 males) aged 12-18. Indicators of body composition were determined by body mass index (BMI), waist circumference, waist-to-height ratio, skinfolds, and percentage of body fat (%BF). Components of physical fitness were assessed by the Assessing Level of Physical Activity (ALPHA) health-related fitness test battery for youth. Results: In the 2-year follow-up, significant (p < 0.05) decreases in BMI and increases in cardiorespiratory fitness and handgrip strength were seen for both groups; decreases in %BF were only seen for participants with DS; and increases in standing long jump were seen only for TD adolescents. Conclusions: Results indicate that during the 2-year study period, there were significant decreases in BMI and significant increases in handgrip strength and cardiorespiratory fitness in the TD group. For participants with DS, there was a significant decrease in %BF. However, participants with DS did not exhibit improvements in physical fitness.