The association between physical fitness and health in a nationally representative sample of Canadian children and youth aged 6 to 17 years

The Longitudinal Association of Cardiorespiratory Fitness and Adiposity With Clustered Cardiometabolic Risk: A Mediation Analysis

PURPOSE

Previous literature has demonstrated the mediating role of adiposity in the association between cardiorespiratory fitness (CRF) and cardiometabolic risk as well as the potential role of CRF in attenuating the adverse consequences associated with excess weight. This study aimed to evaluate the mediating role of CRF and adiposity in the possible association with cardiometabolic risk.

METHOD

Observational 3-year longitudinal study that included 420 children and adolescents (10.50 [2.05] y of age at baseline; 56.2% girls). Body mass index (BMI) was calculated, and CRF was evaluated using field assessments. A clustered cardiometabolic risk score (cMetS) was calculated from glucose, systolic blood pressure, total cholesterol/high-density lipoprotein cholesterol ratio, and triglycerides z scores. Analyses evaluated the mediating role of BMI in the association between CRF and cMetS as well as whether CRF mediated the association between BMI and cMetS.

RESULTS

BMI at baseline was directly associated with the cMetS at follow-up (0.102; 95% confidence interval, 0.020 to 0.181), independently of CRF, whereas CRF was only indirectly associated with cMetS at follow-up through BMI (-0.036; 95% confidence interval, -0.070 to -0.009), meaning that the association between CRF and cMetS was explained via the mediation role of BMI.

CONCLUSIONS

BMI presented direct association with cMetS, whereas CRF exhibited indirect association with cMetS mediated via BMI.

Longitudinal development and tracking of cardiorespiratory fitness from childhood to adolescence

BACKGROUND

Cardiorespiratory fitness (CRF) is an important indicator of health in childhood and adolescence but longitudinal studies on the development and tracking of CRF from childhood to adolescence are scarce.

OBJECTIVES

The objectives of this study were (1) to assess longitudinal development and track CRF over 10 years from childhood to adolescence, and (2) to examine potential sex differences in the development and tracking of CRF during this period.

METHODS

Participants were Icelandic children born in 1999, measured at the age of 7 (n = 190, 106 girls), 9 (n = 163, 95 girls), 15 (n = 239, 134 girls), and 17 (n = 202, 119 girls). CRF was assessed with a maximal cycle ergometer test and expressed as maximal power output (Max W) and maximal power output relative to lean mass (W/kgLM). Multilevel regression models were used to study the longitudinal development of CRF, and tracking was assessed with Spearman's rank correlation, logistic regression, and the percentage of participants remaining in low, moderate, or high CRF categories between measurements.

RESULTS

Max W and W/kgLM increased for both boys and girls up to age 15. Max W plateaued for both boys and girls while W/kgLM plateaued for girls but declined for boys from age 15 to 17. Boys had higher Max W than girls from age 15 and higher W/kgLM from age 9. CRF tracked at low to moderate levels from childhood to adolescence and at high levels in adolescence, with higher values observed for boys than girls.

CONCLUSIONS

Age 15 was a critical time point in the development of CRF, with values starting to plateau for girls and decline for boys. The results support early intervention for improved CRF in later years, with interventions targeting all children, regardless of their CRF level.

Moderating role of 1-minute abdominal test in the relationship between cardiometabolic risk factors and adiponectin concentration in adolescents

BACKGROUND

Adiponectin is an anti-inflammatory cytokine secreted by adipose tissue, has been associated with adiposity and cardiometabolic risk, and has controversial results with muscular fitness. The aim of this study was to analyze the interaction of 1-minute abdominal test in the relationship between adiposity, body composition, cardiometabolic risk and adiponectin concentration in adolescents.

METHODS

This is a cross-sectional study conducted with 62 adolescents of both sexes, aged 11 to 16 years, approved by the Ethics Committee of Research in Humans (CAEE: 62963916.0.0000.5223). Body mass, height, abdominal circumference (AC), waist circumference (WC), fat mass (FM), fat-free mass (FFM), high density lipoprotein (HDL-c), low density lipoprotein (LDL-c), triglycerides (TG), adiponectin, systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean blood pressure (MBP), 1-minute abdominal test (ABD) were measured. Body mass index (BMI), z-score BMI (BMI-z), triponderal mass index (TMI), and waist-to-height ratio (WHtR) were calculated. The macro PROCESS for SPSS v.24.0 was used for moderation analyses, with linear regression models.

RESULTS

Inverse interactions were found for adiposity (BMI, BMI-z, TMI, AC, WC, WHtR), body composition (FM, FFM) and CMRF (SBP, DBP, MBP, TG) versus 1-minute abdominal test with adiponectin concentration, demonstrating that abdominal test is a moderator in these relationships.

CONCLUSION

We conclude that 1-minute abdominal test may play an important role in the relationship between obesity and cardiometabolic risk. We found that muscular fitness can confer a protective effect on adolescents with high levels of abdominal test.

Effects of cardiorespiratory fitness and body mass index on cardiometabolic risk factors in schoolchildren

INTRODUCTION

High levels of physical fitness established during childhood and adolescence have been associated with positive effects on cardiometabolic risk factors (CMRF), which persist into adulthood. Conversely, a sedentary lifestyle, overweight, and obesity during this period are considered public health problems. These conditions tend to worsen in adulthood, increasing the incidence of chronic diseases, deteriorating CMRF, and consequently leading to higher comorbidity and mortality rates.

OBJECTIVE

To investigate the effect of cardiorespiratory fitness (CRF) and body mass index (BMI) on CMRF in children and adolescents.

METHODS

The sample consisted of 49 schoolchildren of both sexes aged 10-17 years. Anthropometric assessments, CRF test, muscle strength test, and blood pressure (BP) measurement were conducted. Participants were allocated into groups based on BMI (eutrophic, overweight, obese), and CRF levels (low-fit, normal-fit, and high-fit).

RESULTS

Obese individuals had lower CRF values compared to the eutrophic and overweight groups. The cardiometabolic risk profile (CMRP) was significantly higher in the obese group compared to the eutrophic group but showed no significant difference compared to the overweight group. The hight-fit group had lower CMRP values compared to the low-fit group.

CONCLUSIONS

Higher BMI and CRF values had negative and positive effects on CMRF and CMRP in schoolchildren, respectively. Overweight or obese schoolchildren with low levels of CRF constitute an unfavourable cardiometabolic risk profile.

Assessment of physical activity among adolescents: a guide to the literature

Purpose

The aim of this article is to systematically review articles and annual reports concerning young peoples' physical activity (PA) and linking this to considerations of the state and national defense.

Method

A systematic search of the literature included an analysis of publications accessible in global databases and other available books, student papers, and projects. The articles and reports were categorized based on year of publication, methods used, age of respondents, sample size, country, and digital object identifier (DOI).

Results

The result of this search is an overview of the extent and manner in which the worldwide scientific community is addressing the current situation and the long-term development of the physical fitness of adolescents. This publication also maps to what extent professional publications and articles are addressing PA from the perspective of the needs of armies and armed forces of various countries around the world.

Conclusions

The article provides a systematic overview of methods used to measure PA, and an overview of articles dealing with assessing PA. The examined articles indicate that from the perspective of not only national defense, but also health and overall quality of life, in particular, we need initiatives to encourage and motivate young people to increase their everyday PA. The research therefore also includes an overview of factors that may considerably influence PA. The results ascertained in this publication will be used, i.a. for investigating a longitudinal defense research project of the Ministry of Defense of the Czech Republic in which the authors are participating.

Effects of Auricular Acupressure on Hip Flexibility and Pain in Taekwondo Participants: Randomized Controlled Trial

BACKGROUND

In sports, hip flexibility is essential to reduce injuries and improve performance.

AIM

This study aimed to examine the effects of auricular acupressure on hip flexibility and pain in Taekwondo participants.

METHOD

This randomized controlled trial was performed in the Republic of Korea from January 2021 to August 2021. The Numeric Rating Scale for Pain and Hip Flexibility was used. Twenty-one participants received auricular pressure once weekly for six weeks, while 17 participants did not receive any intervention. Auricular acupressure was applied to the hip (AH13), Shinmun, and auricular acupressure points associated with the pain areas reported by the participants.

RESULTS

Auricular acupressure improved hip flexibility (t = 2.67, p = .011) and back pain (t = 2.11, p = .043). The mean difference in post-pretest hip flexibility in the experimental group was 16.24 degrees (±13.63), whereas that in the control group was 4.77 degrees (±15.07). The mean difference in the experimental group's pre-post-test scores of back pain was 1.24 (±2.64), whereas that in the control group was 0.18 (±1.41).

CONCLUSIONS

The results of this study showed that auricular acupressure could be used to treat pain and improve hip flexibility.

Participating in a School-Integrated Daily Exercise Program Improves Motor Performance Significantly in School-Children

Children's sedentary time has increased, while daily physical activity and motor performance have decreased. We evaluated an integrated school-based exercise program by assessing changes in motor skills after one year and comparing these changes to children who did not participate. We included 303 children from five schools in this longitudinal study and assigned them either to the exercise group (EG; n = 183 with daily exercise program) or the waiting group (WG; n = 120). Motor skills were assessed at baseline and after one year. Mixed modeling was used to analyze inter-group differences of change in motor skills and to determine the effect of sex, age group, and weight status. EG improved more strongly than WG for sprint, side jumps (both p = 0.017), stand and reach (p = 0.012), and ergometry (p ≤ 0.001) when compared to WG. Girls improved more strongly in the sit-ups than boys, second graders more than fifth graders in the backwards balance and the ergometry, and non-overweight children more in the standing long jump than overweight children. The exercise program is effective in increasing motor skills and physical fitness. Girls were not disadvantaged, and overweight children profited as much as their non-overweight peers in all categories but one.

Longitudinal Changes of Cardiorespiratory Fitness Performance in High School: Association with Individual and School-Based Variables

This study aimed to model adolescents' cardiorespiratory fitness performance change trajectories longitudinally across high school years and its relation to school- and individual/student-level factors. We employed hierarchical linear modeling to examine longitudinal cardiorespiratory fitness performance changes, as measured by the progressive aerobic capacity endurance run (PACER), over the years, between sexes, and in association with the school-level variables. Participants were 76,227 adolescents from 80 high schools in the mid-Atlantic region of the United States. School-level academic performance (SAP), the percent of students eligible for free and reduced-price meals (FARM), and physical education student-faculty ratio were obtained with permission from the school districts. The number of laps completed in PACER test improved throughout the first three years of high school, however, proportions of those within the healthy fitness zone (HFZ) decreased overall from 9th to 11th grade. Furthermore, the number of laps completed by adolescents appeared to have plateaued at 11th grade, with a significant decline during the final year of high school. Sex-based discrepancies in performance in meeting HFZ were evident, where girls significantly outperformed boys during 9th and 10th grades, and boys significantly outperformed girls during 12th grade. Additionally, SAP and FARM were positively and negatively, respectively, significantly associated with PACER performance at the school level. The odds ratio of adolescents performing in the HFZ declined significantly over the years, even though the number of PACER laps improved in the first three years. Concerted efforts should be targeted at improving cardiorespiratory fitness in high school due to its positive relationship to academic achievement in schools, and negative association with cardiovascular disease, metabolic syndrome, obesity, and all-cause mortality in adulthood.

Cross-sectional association between physical fitness and cardiometabolic risk in Chilean schoolchildren: the fat but fit paradox

BACKGROUND

Previous studies have examined the "fat but fit" paradox, revealing that greater levels of physical fitness may diminish the harmful consequences of excess weight on cardiometabolic risk. Despite the above, specific information about the "fat but fit" paradox in prepuberal population is scarce. The aim of this study was to determine the relationship between cardiometabolic risk across (individual and combined) physical fitness and excess weight status and whether the "fat but fit" paradox is met in the sample of schoolchildren analyzed.

METHODS

A cross-sectional study was conducted including 452 children (59.1% girls), aged 7-9 years from Santiago (Chile). Physical fitness was assessed as cardiorespiratory fitness and muscular fitness. Cardiorespiratory fitness was determined by the 6-minute-walk-test and muscle strength was assessed by the handgrip and standing long jump tests. Excess weight (overweight and obesity) was computed through body mass index (z-score). Cardiometabolic risk was established by summing the z-score of the serum glucose, triglycerides, high-density lipoprotein, insulin and waist-to-height ratio.

RESULTS

Schoolchildren with high physical fitness (individual or combined) showed the lowest cardiometabolic risk mean scores (P for trend <0.001 for all physical fitness groups). Conversely, schoolchildren with low physical fitness (individual or combined) showed the highest cardiometabolic risk mean scores (P for trend <0.001 for all categories). Additionally, schoolchildren without excess weight and with high individual or combined physical fitness status exhibits lower cardiometabolic risk mean scores compared to schoolchildren with excess weight and low physical fitness status (individual or combined) (P for trend <0.001 for all physical fitness groups). A lower odd of having high cardiometabolic risk was found in schoolchildren without excess weight and with both high physical fitness (both cardiorespiratory fitness and muscular fitness) [odds ratio (OR) =0.08; 95% confidence interval (CI): 0.04 to 0.16] in comparison to those with excess weight and low physical fitness.

CONCLUSIONS

Our results suggest that improvements in both fatness and aerobic fitness could be associated with lower cardiometabolic risk.

Muscular Fitness and Cardiometabolic Variables in Children and Adolescents: A Systematic Review

BACKGROUND

The importance of muscular fitness (MF) in the performance of activities of daily living is unequivocal. Additionally, emerging evidence has shown MF can reduce cardiometabolic risk in children and adolescents.

OBJECTIVES

The purpose of this study was to examine and summarize the evidence regarding the relationship between MF phenotypes (i.e., maximum muscular strength/power, muscular endurance, and maximum muscular strength/power/endurance) and cardiometabolic variables (obesity, blood pressure, lipids, glucose homeostasis, inflammatory markers, and clustered cardiometabolic variables) in children and adolescents.

DESIGN

This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and was registered with PROSPERO, number CRD42020179273.

DATA SOURCES

A systematic review was performed on five databases (PubMed, EMBASE, SciELO, Scopus, and Web of Knowledge) from database inception to May 2020, with complementary searches in reference lists.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Eligibility criteria included (1) a study sample of youth aged ≤ 19 years, (2) an assessment of MF with individual or clustered cardiometabolic variables derived from adjusted models (regardless of test/measurement adopted or direction of reported association), and (3) a report of the association between both, using observational studies. Only original articles published in peer-reviewed journals in English, Portuguese, and Spanish languages were considered. The quality of the included studies was assessed by using the National Heart, Lung, and Blood Institute checklist. The percentage of results reporting a statistically significant inverse association between each MF phenotype and cardiometabolic variables was calculated.

RESULTS

Of the 23,686 articles initially identified, 96 were included (77 cross-sectional and 19 longitudinal), with data from children and adolescents from 35 countries. The score for the quality of evidence ranged from 0.33 to 0.92 (1.00 maximum). MF assessed by maximum muscular strength/power was inversely associated with lower obesity (64/113 total results (56.6%)) and reduction in clustered cardiometabolic risk (28/48 total results (58.3%)). When assessed by muscular endurance, an inverse association with obesity (30/44 total results (68.1%)) and cardiometabolic risk (5/8 total results (62.5%)) was identified. Most of the results for the relationship between MF phenotypes with blood pressure, lipids, glucose homeostasis, and inflammatory markers indicated a paucity of evidence for these interrelationships (percentage of results below 50.0%).

CONCLUSION

MF assessed by maximum muscular strength/power or muscular endurance is potentially associated with lower obesity and lower risk related to clustered cardiometabolic variables in children and adolescents. There is limited support for an inverse association between MF with blood pressure, lipids, glucose homeostasis biomarkers, and inflammatory markers in children and adolescents.

Sports activity and changes in physical fitness of Polish children and adolescents: OSF study

BACKGROUND

Physical activity promotion programs for children and adolescents should constitute the basis of any national health policy aiming to improve physical fitness, which is a significant health indicator in children, adolescents, adults as well as elderly persons.

METHODS

The study included 1,230 children and adolescents aged 8-16 years (60.1% of girls) from Poland. Five hundred and twenty-seven persons covered by the survey (42.8%) participated in physical activity promotion called "Athletics for All!" (AFA) as an experimental group and 703 peers not participating in any forms of physical extra-curricular activities as a control group. Participants were measured for basic anthropometric parameters and body mass indices were calculated: Body Mass Index (BMI) and Ponderal Index (PI). Evaluation of physical fitness was made using the OSF Test (3 × 10 m shuttle run, standing broad jump, 1 kg medicine ball overhead throw, 4-min run). Comparative analysis between the experimental and control groups was carried out using the T-test for independent samples. Analysis of correlations between quantitative variables was performed with Pearson's r coefficient.

RESULTS

Statistically significant differences in all the tests were noted between the experimental group (AFA) and the control group in favor of the former one. Taking into account reference ranges of BMI created according to the latest Polish norms, statistically significant differences were noted between the subgroups in all physical fitness tests. As far as PI is concerned, in the AFA group significant differences were noted in all physical fitness tests between subgroups created in accordance with the aforementioned norms.

CONCLUSION

The findings of our study show that it is necessary to introduce physical activity promotion programs for children and adolescents. Such programs should constitute the basis of national health policy aiming at improving physical fitness among young people.

Promoting healthy lifestyle behaviours in youth: Findings from a novel intervention for children at risk of cardiovascular disease

Objectives

Obesity is the most prevalent risk factor for cardiovascular disease (CVD) in children. We developed a 2-year lifestyle intervention for youth at risk of CVD. We assessed changes in body mass index z-scores (zBMI) and key cardiometabolic risk factors, physical fitness, and capacity among those who completed the program.

Methods

The CIRCUIT program is a multidisciplinary lifestyle intervention for children aged 4 to 18 years at risk of CVD, based on a personalized plan to improve cardiometabolic outcomes by increasing physical activity and reducing sedentary behaviours. Both at baseline and 2-year follow-up, we measured zBMI, blood pressure z-scores (zBP), adiposity (%body and %trunk fat), fasting blood glucose and lipid profile, aerobic (VO2max) and anaerobic (5×5 m shuttle run test) fitness, and physical capacity indicators. Differences between baseline and follow-up were examined using paired t-tests (for age-sex standardized outcomes) and multivariable mixed effect models, adjusted for age and sex (for other outcomes).

Results

Among the 106 participants (53 males) who completed the 2-year program, mean age at baseline was 10.9 years (SD=3.2). After 2 years, zBMI and diastolic zBP decreased by 0.30SD (95% CI: −0.44; −0.16) and 0.43SD (95% CI: −0.65; −0.23), respectively. Participants improved %body and %trunk fat, lipid profile, aerobic and anaerobic fitness levels, and physical capacity (p&lt;0.02). No changes in systolic zBP nor in fasting plasma glucose were observed.

Conclusion

Our findings showed improved zBMI, cardiometabolic outcomes, physical fitness, and capacity among children at risk of CVD, suggesting that CIRCUIT is a promising intervention.

Relationship between waist circumference and cardiorespiratory fitness in Chinese children and adolescents: Results from a cross-sectional survey

Background

This article assessed the relationship between waist circumference (WC) and cardiorespiratory fitness (CRF) of children and adolescents aged 7–18 years.

Methods

Using a stratified cluster random sampling method, 92,574 children and adolescents (47,364 males and 45,210 females) were extracted. CRF was measured by performance in the 20 m shuttle run test (20mSRT) and the subsequent estimation of maximal oxygen consumption (V˙O_2max) using the Léger equations. Participants were divided into five groups of WC percentiles and three groups of CRF percentiles by the Lambda Mu Sigma (LMS). The correlation between WC and CRF was examined by one-way ANOVA and curvilinear regression analysis.

Results

WC increased with age, while V˙O_2max showed an age-related decline. Controlling for gender, urban, and rural factors, for children and adolescents aged 10–12, 13–15, and 16–18 years, the V˙O_2max Z-score of the normal WC group was significantly higher than the very low WC group (P < 0.05). Controlling for gender, urban, and rural factors, for participants aged 7–18 years, the V˙O_2max Z-score of the normal WC group was significantly higher than the high WC group and the very high WC group (P < 0.05).

Conclusions

It generally shows a “parabolic” trend between WC-Z and V˙O_2max-Z. The CRF among children and adolescents in the normal WC group is significantly higher than that in the low and the high WC groups.

Cardiorespiratory Fitness Associates with Blood Pressure and Metabolic Health of Children-The Arkansas Active Kids Study

INTRODUCTION

High blood pressure (HBP) in children causes preclinical damage to the heart and accelerates atherosclerosis. Current pharmacological treatments have limited ability to prevent end-organ damage, particularly that of the kidneys. A contrasting element between adult versus pediatric HPB treatment is the emphasis in adults on exercise regimens that target increments in cardiorespiratory fitness (CRF; peak oxygen consumption [V˙O2peak]). The aim of this study was to evaluate the association of CRF with blood pressure percentiles and blood pressure status in children with normal and excessive adiposity (NA vs EA). An exploratory aim was to measure associations of CRF with (a) other cardiovascular disease risk factors commonly found in children with HBP and (b) kidney function.

METHODS

Children (n = 211) attended one study visit. CRF was measured using an incremental bike test and body composition by dual-energy x-ray absorptiometry. Fat-free mass (FFM) index was calculated as kilograms of FFM per square meter. Multiple logistic and linear regression analyses were used to model the probability of HBP and other variables of interest (plasma lipids, HOMA2-IR, alanine aminotransferase, and estimated glomerular filtration rate) against V˙O2peak.

RESULTS

CRF interacted with adiposity status in predicting the probability of HBP. Each additional milliliter per minute per FFM index in V˙O2peak decreased the odds of HBP by 8% in the EA group only (odds ratio = 0.92, 95% confidence interval = 0.87-0.99). Systolic and diastolic blood pressure percentiles decreased, and estimated glomerular filtration rate increased with increasing CRF in both adiposity-level groups. HOMA2-IR and alanine aminotransferase decreased with increasing CRF in children with EA only.

CONCLUSIONS

Higher CRF associated with decreased probability of clinical HBP, lower insulin resistance, and improved liver function in children with EA. Yet blood pressure percentiles and kidney function improved with increasing CRF irrespective of adiposity status.

Bi-directional relationships between physical activity and mental health among a large sample of Canadian youth: a sex-stratified analysis of students in the COMPASS study

Objective

The aim of this research was to examine the bidirectional association between self-reported symptoms of mental disorder and physical activity among a large sample of Canadian secondary school students over time.

Methods

Linked survey data were obtained from 28,567 grade 9 to 12 students across Canada participating in two waves of the COMPASS Study (2017–18; 2018–19). Autoregressive cross-lagged models were run to examine the reciprocal relationships between self-reported moderate-to-vigorous physical activity (MVPA) and symptoms of depression (CESD-10) and anxiety (GAD-7). Models were stratified by gender, and accounted for grade, ethno-racial identity, and school-level clustering.

Results

Autoregressive associations show that neither symptoms of anxiety nor depression, at baseline, were predictive of mean MVPA at follow-up – consistent for the full sample and among both males and females. Higher MVPA among males at baseline was associated with lower symptoms of both anxiety (β = − 0.03, p = 0.002) and depression (β = − 0.05, p < 0.001) at follow-up. However, among females, higher MVPA at baseline was associated with greater symptoms of anxiety (β = 0.03, p < 0.001), but not symptoms of depression (β = 0.01, p = 0.073), at follow-up.

Conclusion

In our large sample of Canadian secondary school students, associations between physical activity and symptoms of mental disorder were not bi-directional, and these relationships differed in males and females. This study illustrates the complex nature of the relationship between physical activity and symptoms of mental disorder among youth. While results support the benefits of promoting physical activity among males to prevent or manage internalizing symptoms, the relationship among females warrants further investigation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12966-021-01201-z.

Insufficient Physical Fitness and Deficits in Basic Eating Habits in Normal-Weight Obese Children Are Apparent from Pre-School Age or Sooner

Normal-weight obesity appears to be an extended diagnosis/syndrome associated with insufficient physical fitness levels and inadequate eating habits at least from school years. However, its relation to long term health parameters in pre-school children remains unknown, even though pre-school age is crucial for the determining healthy lifelong habits. Therefore, the aim of the current study was to investigate the differences in physical fitness level and basic eating habits between normal-weight obese, normal-weight non-obese, and overweight and obese preschoolers. The research sample consisted of 188 preschoolers aged 4.0–6.9 years (M_age = 5.52 ± 0.8 year), normal-weight obese = 25; normal-weight non-obese = 143, overweight and obese = 20. Body composition was measured using bio-impedance InBody230. Six tests assessed the physical fitness level: sit-ups; standing long jump; shuttle running 4 × 5 meters; throwing with a tennis ball; multistage fitness tests; sit and reach. A four-item eating habits questionnaire for parents focusing on breakfast regularity, consumption of sweet foods and drinks, selection of food and attitude towards eating was used. A non-parametric analysis of variance and Fisher’s exact test along with suitable effect sizes were used for data processing of physical fitness tests and the basic eating habits questionnaire, respectively. Normal-weight obese children performed significantly worse (from p = 0.03 to p < 0.001, ES ω2-G = low to medium) in muscular fitness, cardiorespiratory fitness and running agility compared to normal-weight non-obese counterparts and did not significantly differ in the majority of physical fitness performance tests from overweight and obese peers. In basic eating habits, normal-weight obese boys preferred significantly more sweet foods and drinks (p = 0.003 ES = 0.35, large), while normal-weight obese girls had significantly more negative attitude towards eating (p = 0.002 ES = 0.33, large) in comparison to their normal-weight non-obese peers. Normal-weight obesity seems to develop from early childhood and is associated with low physical fitness and deficits in eating habits which might inhibit the natural necessity for physically active life from pre-school age or sooner.

Health-Related Criterion-Referenced Cut-Points for Cardiorespiratory Fitness Among Youth: A Systematic Review

BACKGROUND

Cardiorespiratory fitness (CRF), which reflects the overall aerobic capacity of the cardiovascular, respiratory, and muscular systems, is significantly related to health among youth.

OBJECTIVE

The aim of this systematic review was to identify health-related criterion-referenced cut-points for CRF among youth aged 5-17 years.

METHODS

A systematic search of two electronic databases (MEDLINE and SPORTDiscus) was conducted in September 2020. Only peer-reviewed studies that developed health-related criterion-referenced cut-points for CRF among youth were eligible provided they included (1) youth aged 5-17 years from the general population; (2) at least one quantitative assessment of CRF (e.g., peak oxygen uptake [[Formula: see text]O_2peak]); (3) at least one quantitative assessment of health (e.g., cardiometabolic risk); (4) a criterion for health; and (5) a quantitative analysis (e.g., receiver operating characteristic [ROC] curve) of at least one health-related cut-point for CRF. A narrative synthesis was used to describe the results of the included studies.

RESULTS

Collectively, 29 included studies developed health-related criterion-referenced cut-points for CRF among 193,311 youth from 23 countries. CRF cut-points, expressed as [Formula: see text]O_2peak, estimated using the 20-m shuttle run test, demonstrated high discriminatory ability (median area under the curve [AUC] ≥ 0.71) for both cardiometabolic and obesity risk. Cut-points derived from maximal cycle-ergometer tests demonstrated moderate discriminatory ability (median AUC 0.64-0.70) for cardiometabolic risk, and low discriminatory ability for early subclinical atherosclerosis (median AUC 0.56-0.63). Cut-points for CRF using submaximal treadmill exercise testing demonstrated high discriminatory ability for cardiometabolic risk, but only moderate discriminatory ability for obesity risk. CRF cut-points estimated using submaximal step testing demonstrated high discriminatory ability for cardiometabolic risk and moderate discriminatory ability for high blood pressure, while those for the 9-min walk/run test demonstrated moderate-to-high discriminatory ability for obesity risk. Collectively, CRF cut-points, expressed as [Formula: see text]O_2peak, demonstrated moderate-to-high discriminatory ability (median AUC ≥ 0.64) for cardiometabolic risk, obesity risk, and high blood pressure.

CONCLUSIONS

Currently, there is too wide a range of health-related criterion-referenced cut-points for CRF among youth to suggest universal age- and sex-specific thresholds. To further inform the development of universal cut-points, there is a need for additional research, using standardized testing protocols and health-risk definitions, that examines health-related criterion-referenced cut-points for CRF that are age, sex, and culturally diverse.

CLINICAL TRIALS REGISTRATION

PROSPERO registration number: CRD42020207458.

Healthier Minds in Fitter Bodies: A Systematic Review and Meta-Analysis of the Association between Physical Fitness and Mental Health in Youth

BACKGROUND

Physical fitness is an important marker of current and future health status, yet the association between physical fitness and indicators of mental health in youth has not been systematically reviewed and meta-analyzed.

OBJECTIVE

The aim of this work was to systematically review and meta-analyze the association between physical fitness components (i.e. cardiorespiratory fitness, muscular fitness, speed-agility, flexibility and fitness composite) and mental health indicators (i.e. psychological well-being and psychological ill-being) in preschoolers, children and adolescents.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Systematic searches were conducted in PubMed, Web of Science and Scopus from database inception to May 2020.

ELIGIBILITY CRITERIA

Studies (cross-sectional, longitudinal and intervention designs) were included if they measured at least one physical fitness component and one mental health indicator in healthy youth (2-18 years).

RESULTS

A total of 58 unique studies (52 cross-sectional, 4 longitudinal and 4 intervention studies) met all eligibility criteria and were included. There was a significant positive overall association between physical fitness and mental health in children and adolescents (pooled r = 0.206, p < 0.001). We found suggestive evidence of moderation by age group, fitness components and socioeconomic status (all p < 0.08). No relevant studies focusing on preschoolers were identified. Evidence based on longitudinal and intervention studies was limited.

CONCLUSION

We observed a small to medium sized positive association between physical fitness and overall mental health in youth. However, as the majority of studies were cross-sectional, additional longitudinal and intervention studies are needed to provide evidence of causation.

TRIAL REGISTRATION

PROSPERO registration number CRD42017080005.

Helping Children with Obesity "Move Well" To Move More: An Applied Clinical Review

ABSTRACT

Children with obesity experience musculoskeletal pain and reduced physical function and well-being, which collectively impact their fitness, strength, motor skills, and even their ability to undertake simple tasks, like walking and climbing stairs. Disrupting obesity-related disability may be critical to increasing children's physical activity. Thus, barriers to movement should be considered by health practitioners to improve the efficacy of prescribed physical activity. This applied clinical review highlights key subjective and objective findings from a hypothetical case scenario, linking those findings to the research evidence, before exploring strategies to enhance movement and increase physical activity.

Longitudinal changes in maximal oxygen uptake in adolescent girls and boys with different training backgrounds

The purpose of this study was to investigate the effects of high-volume endurance training on the development of maximal oxygen uptake (VO_2max ) in physically active boys and girls between the ages of 12 and 15 years, using a longitudinal design. The children participated in organized training in sports clubs for an average of 7-10 hours per week, with one group undertaking a high volume of endurance training (~7 hours per week; End boys, n = 23 and End girls, n = 17) and the other group having a primary focus on technical and tactical skill development, undertaking low volumes of endurance training (~1.6 hours per week; non-End boys, n = 29 and non-End girls, n = 9). VO_2max and anthropometrics were assessed at age 12, 13, and 15. At age 12, VO_2max was 58.9 (5.6), 65.5 (7.2), 56.5 (6.5), and 58.8 (7.9) mL·kg^-1 ·min^-1 in End girls, End boys, non-End girls, and non-End boys, respectively. Over the three years, there was no difference between the training groups in the development of VO_2max independent of scaling. In boys, VO_2max relative to body mass (BM) did not change from age 12 to 15, while VO_2max tended to decrease relative to fat-free mass (FFM). In girls, VO_2max relative to BM decreased slightly from age 12 to 15, with no changes over the years relative to FFM. The present longitudinal study suggests that in growing active children during puberty, high volumes of systematic endurance training do not have an additional effect on VO_2max compared with similar volume of training mainly aiming at developing motor skills.

Reciprocal Longitudinal Relationship Between Fitness, Fatness, and Metabolic Syndrome in Brazilian Children and Adolescents: A 3-Year Longitudinal Study

PURPOSE

To verify the reciprocal longitudinal relationships between cardiorespiratory fitness (CRF), percentage body fat (%body fat), and metabolic syndrome in Brazilian primary school students.

METHOD

This longitudinal study involved 420 children and adolescents followed for 3 years (2011-2014). The continuous Metabolic Syndrome (cMetSyn) score was calculated by summing adjusted z scores of glucose, systolic blood pressure, total cholesterol/high-density lipoprotein cholesterol ratio, triglycerides, and waist circumference. The CRF was assessed using running/walking tests, and %body fat was assessed through sex-specific 2-site skinfold thickness. Cross-lagged panel models were used to analyze longitudinal reciprocal relationships between CRF and %body fat with cMetSyn.

RESULTS

Results indicated that 2011 %body fat significantly predicted both 2014 CRF scores and 2014 cMetSyn scores (P < .001); however, 2011 CRF only predicted 2014 %body fat (P < .001) but not 2014 cMetSyn (P = .103). Furthermore, 2011 cMetSyn predicted 2014 %body fat (P = .002). The model explained 36%, 48%, and 37% of the variance in 2014 CRF, %body fat, and cMetSyn, respectively.

CONCLUSION

The results suggest a reciprocal inverse relationship between %body fat and metabolic syndrome risk and that %body fat may play a more important role in the risk of developing metabolic syndrome compared with CRF.

A Systematic Analysis of Temporal Trends in the Handgrip Strength of 2,216,320 Children and Adolescents Between 1967 and 2017

OBJECTIVE

To estimate national and international temporal trends in handgrip strength for children and adolescents, and to examine relationships between trends in handgrip strength and trends in health-related and sociodemographic indicators.

METHODS

Data were obtained through a systematic search of studies reporting temporal trends in the handgrip strength for apparently healthy 9-17-year-olds, and by examining large national fitness datasets. Temporal trends at the country-sex-age level were estimated by sample-weighted regression models relating the year of testing to mean handgrip strength. International and national trends were estimated by a post-stratified population-weighting procedure. Pearson's correlations quantified relationships between national trends in handgrip strength and national trends in health-related/sociodemographic indicators.

RESULTS

2,216,320 children and adolescents from 13 high-, 5 upper-middle-, and 1 low-income countries/special administrative regions between 1967 and 2017 collectively showed a moderate improvement of 19.4% (95% CI 18.4-20.4) or 3.8% per decade (95% CI 3.6-4.0). The international rate of improvement progressively increased over time, with more recent values (post-2000) close to two times larger than those from the 1960s/1970s. Improvements were larger for children (9-12 years) compared to adolescents (13-17 years), and similar for boys and girls. Trends differed between countries, with relationships between national trends in handgrip strength and national trends in health-related/sociodemographic indicators negligible-to-weak and not statistically significant.

CONCLUSIONS

There has been a substantial improvement in absolute handgrip strength for children and adolescents since 1967. There is a need for improved international surveillance of handgrip strength, especially in low- and middle-income countries, to more confidently determine true international trends.

PROSPERO REGISTRATION NUMBER

CRD42013003657.

Associations between fitness, physical activity and mental health in a community sample of young British adolescents: baseline data from the Fit to Study trial

OBJECTIVES

To examine relationships between fitness, physical activity and psychosocial problems among English secondary school pupils and to explore how components of physically active lifestyles are associated with mental health and well-being.

METHODS

A total of 7385 participants aged 11-13 took a fitness test and completed self-reported measures of physical activity, attitudes to activity, psychosocial problems and self-esteem during the Fit to Study trial. Multilevel regression, which modelled school-level cluster effects, estimated relationships between activity, fitness and psychosocial problems; canonical correlation analysis (CCA) explored modes of covariation between active lifestyle and mental health variables. Models were adjusted for covariates of sex, free school meal status, age, and time and location of assessments.

RESULTS

Higher fitness was linked with fewer internalising problems (β=-0.23; 95% CI -0.26 to -0.21; p<0.001). More activity was also related to fewer internalising symptoms (β=-0.24; 95% CI -0.27 to -0.20; p<0.001); the relationship between activity and internalising problems was significantly stronger for boys than for girls. Fitness and activity were also favourably related to externalising symptoms, with smaller effect sizes. One significant CCA mode, with a canonical correlation of 0.52 (p=0.001), was characterised high cross-loadings for positive attitudes to activity (0.46) and habitual activity (0.42) among lifestyle variables; and for physical and global self-esteem (0.47 and 0.42) among mental health variables.

CONCLUSION

Model-based and data-driven analysis methods indicate fitness as well as physical activity are linked to adolescent mental health. If effect direction is established, fitness monitoring could complement physical activity measurement when tracking public health.

Temporal trends in the sit-ups performance of 9,939,289 children and adolescents between 1964 and 2017

We estimated international/national temporal trends in sit-ups performance for children and adolescents, and examined relationships between national trends in sit-ups performance and national trends in health-related/sociodemographic indicators. Data were obtained by systematically searching studies reporting on temporal trends in sit-ups performance for apparently healthy 9-17 year-olds, and by examining nationally representative fitness datasets. Trends at the country-sex-age level were estimated by sample-weighted regression models relating the testing year to mean sit-ups performance. International/national trends were estimated by a post-stratified population-weighting procedure. Pearson's correlations quantified relationships between national trends in sit-ups performance and national trends in health-related/sociodemographic indicators. A total of 9,939,289 children and adolescents from 31 countries/special administrative regions between 1964 and 2017 collectively showed a large improvement of 38.4% (95% CI: 36.8 to 40.0) or 7.1% per decade (95% CI: 6.8 to 7.4). Large international improvements were experienced by all age and sex groups, with the rate of improvement slowing from 1964 to 2000, stabilizing near zero until 2010, before declining. Trends differed between countries, with national trends in vigorous physical activity a strong, positive correlate of national trends in sit-ups performance. More sit-ups data are needed from low- and middle-income countries to better monitor trends in muscular fitness.

PROSPERO REGISTRATION NUMBER

CRD42013003657.

Relative handgrip strength, nutritional status and abdominal obesity in Chilean adolescents

Handgrip strength (HGS) is a well-established indicator of muscle strength and can help to identify risk of sarcopenic obesity in children. This study explores the relationship between adiposity and muscular strength in healthy Chilean adolescents. Adolescents (n = 491) aged 10–17 were selected from five schools in Santiago, Chile. HGS was determined by dynamometry. Anthropometry (weight, height, waist and mid arm circumference), physical activity and socioeconomic status were also measured. Relative HGS (RHGS) was calculated by dividing maximum HGS of the dominant hand by body-mass index (BMI) and low RHGS was categorized as <25^th percentile by sex. Logistic regression was used to determine the relationship between two markers of adiposity (abdominal obesity category by waist circumference and nutritional status measured by BMI category) and low RHGS, adjusting for possible confounding variables. Participants were on average 13.6y (2.4), 32.8% were overweight or obese and 37.5% were at risk of or had abdominal obesity. RHGS was 1.25 kg/kg/m² overall, with a significant difference by sex (1.51 for boys versus 1.14 for girls). In adjusted analyses, boys and girls with risk of abdominal obesity, had 3.3 (1.6–6.6) and 4.1 (1.8–9.3) increased odds of low RHGS, respectively, compared to boys and girls with normal waist circumference. Those with abdominal obesity compared to normal WC, had 8.5 (3.4–21.4) and 6.5 (2.0–21.3) increased odds of low RHGS for boys and girls, respectively. We observed similar associations for BMI category. In our sample of healthy adolescents, higher adiposity related to greater odds of low muscle strength measured by dynamometry. Considering the demographic shift from a young to an aging population in many countries, along with the increasing prevalence of obesity beginning in childhood, understanding how adiposity relates to low muscle strength is of growing importance.

Temporal Trends in the Association between Participation in Physical Education and Physical Activity among U.S. High School Students, 2011-2017

The purpose of this study was to assess trends in physical education and physical activity among U.S. high school students from 2011 to 2017, respectively, and to evaluate temporal trends in the relationship between physical education class participation and physical activity levels. Data from a total of 51,616 high school students who participated in the Youth Risk Behavior Surveillance System (YRBSS) from 2011 to 2017 were analyzed for this study. Physical education was measured as follows: In an average week when you are in school, on how many days do you go to physical education classes? Physical activity was measured as follows: During the past 7 days, on how many days were you physically active for a total of at least 60 min per day? Meeting physical activity guideline was defined as engaging in 7 days per week of at least 60 min per day. Across the 2011-2017 YRBSS, there were no linear (p = 0.44)/quadratic trends (p = 0.37) in physical education and linear (p = 0.27)/quadratic trends (p = 0.25) in physical activity, respectively. Regarding the trends in the association between physical education and physical activity, there were no statistically significant linear (unstandardized regression coefficient (b) = 0.013, p = 0.43) or quadratic (p = 0.75) trends; however, at the sample level, there was a slight increase in the odds ratio effect sizes from 2011 to 2017 (ES = 1.80-1.98). The pooled association between physical education participation and physical activity was statistically significant, OR = 1.88, 95% CI = 1.75-2.03, p < 0.001. That is, on average across the four YRBSS cycles, students who participated in physical education had 1.88 times higher odds of meeting physical activity guideline when compared to students who did not participate in physical education. The trends of physical education and physical activity did not change between 2011 and 2017. Overall, we observed a significant relationship between participation in physical education and physical activity. There was a non-significant yet stable trend of association between participation in physical education and physical activity over time.

Association between Adherence to the Mediterranean Diet and Physical Fitness with Body Composition Parameters in 1717 European Adolescents: The AdolesHealth Study

Obesity, low levels of physical fitness, and unhealthy eating patterns are responsible for part of the health problems of adolescents today. The current study aimed at examining the association between the adherence to the Mediterranean diet (MD), through each answer to the items of the Adherence to the MD Questionnaire (KIDMED), and physical fitness with body composition parameters (body mass index (BMI), percentage of body fat, and waist circumference) in 1717 European adolescents (N = 900 boys, N = 817 girls). Data of body composition, physical fitness results, and the answers to KIDMED were analyzed by the Student’s t-test. Additionally, the effect size (ES) was calculated and a Chi-square test analyzed the proportion of participants with and without over waist circumference, overfat, and overweight in each KIDMED question. The relative risk of suffering over waist circumference, overfat and overweight in relation to the responses was calculated by Odd-Ratio. Adherence to the MD did not influence the condition of over waist circumference, overfat and overweight, although certain dietary habits were identified as risk factors for their development. Over waist circumference, overfat, and overweight boys and girls presented higher levels of body mass, waist circumference, body fat percentage, and BMI (p < 0.001; ES = 1.73–3.38), as well as lower levels of all the parameters of the physical fitness analyzed (p < 0.001; ES = 0.45–1.08), except the handgrip test. A direct relationship between fitness and over waist circumference, overfat, and overweight was found.

Association between Club Sports Participation and Physical Fitness across 6- to 14-Year-Old Austrian Youth

Changes in social and built environments most likely contribute to a decline in physical activity (PA) and physical fitness in children and adolescents. Organized sports may be an important component in ensuring adequate fitness, which is an important aspect in general health and well-being. The present study examines differences by club sports participation in cardiorespiratory endurance, muscular strength, power, speed, agility, flexibility and balance in 3293 (55.1% male) Austrian children and adolescents between 6 and 14 years of age. Anthropometric measurements (height and weight) were taken and participants completed the German motor test during regular class time. Even though there was no significant difference in body weight between club sports participants and non-club sports participants, club sports participation was associated with higher physical fitness, particularly regarding endurance, strength, power, and agility. Differences by club sports participation, however, declined during the elementary school years (6-10 years of age), while they became more pronounced during middle school years (10-14 years of age). Club sports participation, therefore, may be a viable option in the promotion of physical fitness, particularly during adolescence. At younger ages, other sources of PA, such as physical education and free play, however, should be considered to ensure sufficient fitness levels that contribute to a healthy and active lifestyle.

Establishing modified Canadian Aerobic Fitness Test (mCAFT) cut-points to detect clustered cardiometabolic risk among Canadian children and youth aged 9 to 17 years

The objective of this study was to establish cut-points to identify potential clustered cardiometabolic risk among children (aged 9-13 years) and youth (aged 14-17 years) using the modified Canadian Aerobic Fitness Test (mCAFT). Nationally representative cross-sectional data were obtained from cycles 1 and 2 (2007-2011) of the Canadian Health Measures Survey. Cardiorespiratory fitness was measured using the mCAFT, which was used to estimate peak oxygen consumption. Clustered cardiometabolic health was identified as the mean of 4 standardized variables: sum of 4 skinfolds; total cholesterol-to-high-density lipoprotein ratio; and systolic and diastolic blood pressure. In total, 2106 (49% female) participants were retained for this analysis. The optimal mCAFT cut-point for males was 49 and 46 mL·kg^-1·min^-1 among children and youth, respectively. Among females, the mCAFT cut-point was 46 and 37 mL·kg^-1·min^-1 among children and youth, respectively. In 2016-2017, 83% of females and 71% of males met the new mCAFT cut-points. The mCAFT cut-points can help identify children and youth at potential risk of poor cardiometabolic health in public health surveillance, clinical, and school-based settings. Novelty We developed new mCAFT cut-points to identify potential clustered cardiometabolic risk among Canadian children and youth. These mCAFT cut-points can be used to inform national health surveillance efforts.