Physical fitness in childhood and adolescence: a powerful marker of health

Secular Trends in Physical Fitness of Peruvian Children Living at High-Altitude

The physical fitness of children is an important marker of health, and monitoring its temporal changes provides important information for developing interventions. We aimed to: (1) describe secular trends in physical fitness across age, within each sex, in Peruvian schoolchildren; and (2) verify if these trends are also present when adjusted for changes in height and weight. We sampled 1590 children (707 in 2009; 883 in 2019), aged 6-11 years. Physical fitness was assessed with four tests from the EUROFIT battery. ANOVA and ANCOVA statistical models were used. Results showed that with increasing age, girls and boys were significantly stronger in all PF tests, except for the case of flexibility in girls. In 2019, girls were stronger (handgrip) and more flexible than in 2009; but lower values were evident in standing long jumps in both sexes. Age-by-year interactions were statistically significant for agility in both sexes, with significant differences occurring at different ages. These trends did not change when adjusted for temporal changes in height and weight. Our research provides important data for local governments to implement public policies and practices to improve physical fitness levels in children.

Feasibility and Reliability of Health-Related Physical Fitness Tests in Children and Adolescents with Hearing Impairment

Although research supports the feasibility and reliability of health-related physical fitness (HRPF) tests in typically developing children and adolescents, little is known regarding the feasibility and reliability of these tests for those with hearing impairments (HI). The aim of this study was to evaluate the feasibility and reliability of a HRPF test battery for children and adolescents with HI. A test-retest design with a one-week interval was conducted with 26 participants with HI (mean age: 12.7 ± 2.8 years; 9 male). The feasibility and reliability of seven field-based HRPF tests (i.e., body mass index, grip strength, standing long jump, vital capacity, long distance run, sit-and-reach, one leg stand) were evaluated. All the tests showed high feasibility (completion rate > 90%). Six tests indicated good to excellent test-retest reliability (all intraclass correlation coefficient [ICC] > 0.75) while the one leg stand test showed poor reliability (ICC = 0.36). Relatively large percentages of standard error of measurement (SEM%) and minimal detectable change (MDC%) were observed in the sit-and-reach test (SEM% = 52.4%, MDC% = 145.2%) and one leg stand test (SEM% = 107.9%, MDC% = 299.2%), whereas the rest of the tests demonstrated reasonable SEM% and MDC% values. Collectively, most of the tests can be feasibly and reliably used to assess HRPF for children and adolescents with HI.

Longitudinal associations of movement behaviours with body composition and physical fitness from 4 to 9 years of age: structural equation and mediation analysis with compositional data

BACKGROUND

The associations of movement behaviours (physical activity [PA], sedentary behaviour [SB], and sleep) with body composition and physical fitness from pre-school to childhood, as well as the direction of the associations, could provide important information for healthy lifestyle promotion in children. This study investigated the longitudinal and bidirectional associations of movement behaviours with body composition and physical fitness measured at 4 and 9 years of age.

METHODS

This longitudinal study included baseline (n = 315, 4.5 [SD = 0.1] years) and follow-up data (n = 231, 9.6 [SD = 0.1] years) from the MINISTOP study. Movement behaviours were measured for 7 days using wrist-worn accelerometers, body composition with air-displacement plethysmography, and physical fitness with the ALPHA health-related fitness test battery. Cross-lagged panel models and mediation analyses were performed in combination with compositional data analysis.

RESULTS

We did not observe direct associations of the movement behaviours at 4 years with either body composition or physical fitness at 9 years (all P > 0.05). However, fat mass index at 4 years was negatively associated with vigorous PA (VPA), relative to remaining behaviours (VPA, β = - 0.22, P = 0.002) and light PA (LPA), relative to SB and sleep (β = - 0.19, P = 0.016) at 9 years. VPA (relative to remaining), moderate PA (MPA) (relative to LPA, SB, and sleep), and SB (relative to sleep) tracked from 4 to 9 years (all β ≥ 0.17, all P < 0.002), and these behaviours shared variance with fat mass index (all|β| ≥ 0.19, all P < 0.019), and aerobic, motor, and muscular fitness (all|β| ≥ 0.19, all P < 0.014) at 9 years. Mediation analysis suggested that the tracking of VPA (relative to remaining behaviours) from 4 to 9 years was negatively associated with fat mass index (β ≥ - 0.45, P = 0.012), and positively with aerobic fitness at 9 years (β ≥ 1.64, P = 0.016).

CONCLUSION

PA and SB tracked from the pre-school years into childhood. Fat mass index at 4 years of age was negatively associated with VPA (relative to remaining behaviours) and LPA (relative to SB and sleep) at 9 years of age. The tracking of VPA was associated with lower fat mass index and higher aerobic fitness at 9 years of age. These findings suggest that higher levels of VPA in pre-school age, if maintained throughout childhood, may support the development of healthy body composition and aerobic fitness levels in later childhood.

Motor, Physical, and Psychosocial Parameters of Children with and without Developmental Coordination Disorder: A Comparative and Associative Study

(1) Background: Developmental coordination disorder (DCD) is a chronic impairment that affects several domains that mark the developmental trajectory from childhood to adulthood. Aim: This study examined the differences in physical and psychosocial factors for children with DCD and typical development (TD) and the associations between these factors with gross motor coordination. (2) Methods: Children with DCD (n = 166; age: M = 8.74, SD = 2.0) and TD (n = 243; Age: M = 8.94; SD = 2.0) attending private and public schools were screened using the MABC-2. Children were then assessed using the Körperkoordination test für Kinder (gross coordination), the Perceived Efficacy and Goal Setting System (self-efficacy), horizontal jump (lower limb strength), and dynamometer (handgrip strength). A semi-structured interview was carried out to examine the oriented physical activity practice in the daily routine, the time spent in the activities, and the use of public spaces to practice non-oriented physical activities. (3) Results: Children with TD showed scores significantly higher than children with DCD in almost all factors with small to very large effect sizes; the exceptions were self-care and daily physical activity. The structural equation model showed that for children with DCD, the BMI explained negatively and significantly the motor coordination (b = -0.19, p = 0.019), whereas physical activity (b = 0.25, p < 0.001), lower limb strength (b = 0.38, p < 0.001), and perceived self-efficacy (b = 0.19, p = 0.004) explained it positively. For children with TD, the BMI explained negatively and significantly the motor coordination (b = -0.23, p = 0.002), whereas physical activity (b = 0.25, p < 0.001) and lower limb strength (b = 0.32, p < 0.001) explained it positively. (4) Conclusions: The authors extended previous research by providing evidence that factors affecting motor coordination vary across childhood for children with DCD and TD. Self-efficacy was relevant only in explaining motor coordination for children with DCD.

How Do Health, Biological, Behavioral, and Cognitive Variables Interact over Time in Children of Both Sexes? A Complex Systems Approach

The present study examined gender differences in health, physical activity, physical fitness, real and perceived motor competence, and executive function indicators in three time points, and analyzed the dynamic and non-linear association between health, biological, behavioral, and cognitive variables in children followed over time. A total of 67 children (aged between six and 10 years) were followed during two years and split into two cohorts (six to eight years old: C1; eight to 10 years old: C2). Data regarding health, physical activity, real and perceived motor competence, physical fitness, and executive function indicators were obtained according to their respective protocols. Comparison tests and network analysis were estimated. Significant gender differences were found in both cohorts. The emerged networks indicated different topologies in both cohorts. No clusters were observed between the variables in C1, and there was a greater number of interactions at eight years of age. Sparse networks were observed in children aged eight and 10 years in C2, and greater connectivity was observed at nine years of age between health, physical fitness, motor competence, and physical activity indicators. This study showed that there are non-linear dynamic relationships between health, biological, behavioral, and cognitive variables over time during child development.

Individual and combined impact of physical fitness on health-related quality of life during adolescence: DADOS Study

The purpose of the present study was to investigate the individual and combined impact of physical fitness components at baseline on health-related quality of life (HRQoL) at 24-month follow-up in adolescents. This longitudinal research included 199 adolescents (13.9±0.3 years at baseline) from the DADOS study. Cardiorespiratory fitness was assessed using the 20-m shuttle run test. Muscular strength was assessed using the standing broad jump test. Motor competence was assessed using the 4 × 10-m shuttle run test. A physical fitness z-score was calculated as the mean of the z-scores values of each fitness test. A fitness index ranging from 0 to 3 was created according to the number of physical fitness components in which participants achieved high levels according to normative values. HRQoL was evaluated by the KIDSCREEN-10 questionnaire. Linear regression analyses showed that cardiorespiratory fitness, muscular strength, and the physical fitness z-score at baseline were individually associated with HRQoL at follow-up (β ranging from 0.123 to 0.183; all p < 0.05). Moreover, logistic regression analysis revealed that adolescents with a fitness index ≥1 at baseline were more likely to achieve high HRQoL at 24-month follow-up, compared with their peers with an index of 0 (OR ranging from 3.554 to 9.087; all p < 0.05). Our results revealed an individual and cumulative positive impact of physical fitness at baseline on HRQoL at 24-month follow-up. These findings underline the key role of promoting the enhancement of overall physical fitness components in order to improve adolescents' health and well-being.Highlights Adolescents with high levels of cardiorespiratory fitness, muscular strength and motor competence will benefit from a greater physical and mental well-being over the time.The more physical fitness components with optimal levels, the greater likelihood of reaching better HRQoL over the time.Public health authorities should focus on the promotion of multiple physical fitness components to increase adolescent's likelihood of achieving greater HRQoL over the time.

Influence of Volume and Bouts of Sedentary Time and Physical Activity on School-Aged Youth's Physical Fitness: The UP & DOWN Longitudinal Study

BACKGROUND

The aim of this study was to examine associations of total volume and bouts of sedentary time (ST) and moderate to vigorous physical activity (MVPA) with physical fitness (PF) in youth.

METHODS

This was a 2-year follow-up study with 1418 children and adolescents (51.7% boys). Accelerometers were used to assess ST and MVPA. Cardiorespiratory and muscular fitness values were objectively measured and combined in a global PF variable. Weight status was objectively obtained. Linear regression analyses were used to examine the cross-sectional (using scores at baseline) and longitudinal associations (using the change in the variables) of total volume and bouts of ST and MVPA with PF.

RESULTS

Total ST was negatively associated with global PF (β = -0.488, P < .001 in cross-sectional analysis; β = -0.234, P = .003 in longitudinal analysis). However, this association was not independent of MVPA. Total volume of MVPA showed a positive association with global PF independently of ST and weight status (β = 0.285, P < .001 in cross-sectional analysis; β = 0.119, P = .001 in longitudinal analysis). Longitudinal associations found between ST and MVPA accumulated in bouts of various lengths and global PF became nonsignificant when their respective total volumes are included in the model.

CONCLUSIONS

These results underline the need to accumulate minutes of MVPA, regardless of the bout duration, to increase PF levels in youth.

Adolescents' Flexibility Can Affect Motor Competence: The Pathway from Health Related Physical Fitness to Motor Competence

Motor competence has been shown to predict health-related physical fitness (HRPF) components in youth, but there is indeterminate evidence for the reverse path. Even less is known about the specific relationship between motor competence and flexibility. Our aims in this study were to analyze the relationship between flexibility and motor competence among adolescents; and, secondarily, to examine the relationships between motor competence and other HRPF components (body composition and musculoskeletal fitness). We conducted a longitudinal study (14-months follow-up) with two measurement points of 128 participants (55.5% girls; 45% boys) aged 12-13 years at baseline. We assessed HRPF components at the first time point and determined motor competence at the second time point. We assessed HRPF in terms of body composition (body fat percentage), musculoskeletal fitness (sit-up test), and flexibility (sit and reach). We determined motor competence using the Körperkoordinationstest für Kinder (KTK). We employed multivariate analyses of variance (MANOVA) to examine the effect of HRPF on motor competence through three models, in which each HRPF component was considered an independent variable. Sex, age, physical activity, and body mass index (BMI) z-scores were considered confounders. In our crude models all HRPF components significantly affected motor competence. In adjusted models, flexibility (p = .002) and body composition (p < .001) significantly affected motor competence. Overall, these results supported the assumptions that HRPF components are related to motor competence in adolescence, and that flexibility can affect motor competence in young people.

Longitudinal Associations of Cardiorespiratory Fitness and Poverty With Academic Performance Among Youth

BACKGROUND

Cardiorespiratory fitness (CRF) plays a significant role in health and academic performance in youth. The purpose of this study was to examine the longitudinal relationship between CRF and academic performance from fifth to eighth grade among a large, diverse, and state-wide cohort of students, and to determine the extent to which the relationship between change in CRF and academic performance is moderated by poverty status.

METHODS

CRF and academic performance data were obtained for a retrospective state-wide cohort of 11,013 students with baseline (fifth grade, school year 2015-2016) and follow-up (eighth grade, school year 2018-2019) data. Analysis of covariance was used to examine the association between changes in CRF over a 3-year follow-up period and eighth grade academic performance.

RESULTS

After adjusting for covariates, change in CRF and poverty status were positively and significantly associated with eighth grade academic performance. Poverty status did not significantly moderate the association between changes in CRF and academic performance.

CONCLUSIONS

Schools should prioritize evidence-based policies and programs that optimize students' access to high quantity and quality physical activity throughout the school day. Such efforts can improve and maintain student CRF and thus academic performance outcomes.

Athletic children: Guidelines and monitoring in pediatric orthopedic surgery

In day-to-day practice pediatric orthopedic surgeons often come up against the question of sport. The aim of the present study was to analyze the relationship between sport and childhood, with 3 questions: (1) What are the benefits of sport for children? (2) How to manage high-level child athletes? And (3) What sports are possible after major orthopedic surgery? Sports provide many benefits for children, and are to be encouraged. Sixty minutes' moderate to intense physical activity per day benefits motor development and bone mineralization and reduces the risk of obesity. On the other hand, excessive sports activity, as encountered in high-level sport, can be harmful for the child's development. The amount of training should not exceed a certain threshold in terms of hours per week according to age. Surgical treatment of sport-related traumatic lesions does not necessarily accelerate return to sport: indications need to be reasonable, despite pressure from the patient's circle. Sports are possible after major orthopedic surgery, although return to sport tends to be delayed and the level is lower than preoperatively.

Inequalities in the association between adherence to the Mediterranean diet and physical fitness in the young population during the COVID-19 lockdown

OBJECTIVE

this study analyzed the association between adherence to the Mediterranean diet and proxy-reported physical fitness among Spanish and Brazilian youths during the COVID-19 lockdown according to several inequality indicators.

METHODS

we conducted a cross-sectional study with parents and guardians of children and adolescents from Spain and Brazil. The evaluation process was through the use of online questionnaires. Adherence to the Mediterranean diet was assessed using the Mediterranean Diet Quality Index in Children and Adolescents. Proxy-reported physical fitness was determined using the International Fitness Scale. Inequality indicators (gender, nationality, socioeconomic status, and parents/guardians' education level) were evaluated with a survey completed by the participants' parents/guardians. Binary logistic regression models estimated the association between adherence to the Mediterranean diet and proxy-reported physical fitness, with stratification according to inequality variables. A total sample of 1,099 Spanish and Brazilian individuals (47.6% girls, aged 3 to 17 years) were included in the analysis.

RESULTS

compared to the "improvement needed to Mediterranean diet" category, the "optimal Mediterranean diet" group was significantly associated with "very good" physical fitness in boys (OR = 1.5; 95 % CI: 1.0-2.1) and in participants with parents/legal guardians' education level without university studies (OR = 1.5; 95 % CI: 1.0-2.4).

CONCLUSIONS

gender and parents/guardians' education level plays a significant role in the association between the "optimal Mediterranean Diet" and "very good" physical fitness level in Spanish and Brazilian children and adolescents. Future prospective studies are needed to investigate the role of inequality indicators in this relationship.

Increasing Physical Activity at School Improves Physical Fitness of Early Adolescents

(1) Introduction: Regular physical activity (PA) is an important part of a healthy lifestyle for children and adolescents. The aim of this study was to assess the impact of an increase in organized PA at school on the physical fitness (PF) of early adolescent boys and girls. (2) Methods: A total of 294 children born in 2007 took part in the study. The sample was divided into two groups: of increased PA at school (n = 140, girls n = 66, boys n = 74) and standard PA (n = 154, girls G n = 70, boys n = 84). Increased and standard PA levels consisted of 10 and 4 h of physical education lessons (PE) per week, respectively. PE consisted of team games and fitness exercises. Three of the Eurofit tests, core strength, long jump, and running speed, were used to measure PF. Tests were conducted in May 2018 and 2019, at an average age of a participant of 11 and 12 years, respectively. Descriptive statistics and cluster analysis were applied for analyzing the results. (3) Results: After one year of observation PF of children was improved in both groups (p < 0.001). However, it was greater in the increased PA group than in the standard one. A higher percentage of very good scores and lower of poor and very poor were noted in the increased PA group than the standard one (20.36% vs. 12.90%, p = 0.003 and 18.58% vs. 24.85%, p = 0.022, respectively). Boys obtained better results than girls (p = 0.003). Children achieved the best results in the shuttle run test, and the worst in the core strength. Children with normal body mass obtained better results than those with excessive ones. (4) Conclusions: Increasing the number of PE at school beneficially affects the fitness performance of early adolescents. To improve the health status of adolescents it is advisable to increase the number of compulsory PE lessons in the school curriculum.

Effectiveness of Brainball program on physical fitness of primary school pupils in Vietnam. A longitudinal study

Objective

The present study aimed to evaluate the effectiveness of the Brainballs on the physical fitness of 2nd-grade students at a primary school in Vietnam during and eight months after the experiment.

Methods

The study included 55 pupils (23 boys and 32 girls) aged seven years. The study design was a pedagogical experiment with a parallel-group technique, including experimental and control groups. The examination was carried out in 2019/2020 in three terms pre- (September 2019), post- (January 2020), and follow-up (September 2020). Physical fitness was tested with the use of the International Physical Fitness Test. The Brainball program, conducted twice a week for 35 minutes, combined physical education (PE) with subject-related content, utilizing 100 balls with painted letters, numbers, and signs.

Results

Results show that the fitness level was not increased significantly after 20 weeks of the intervention program, neither in experimental nor control groups. However, it significantly improved eight months later at the follow-up examination. The analysis of covariance indicated that pupils from the experimental group improved significantly on most physical fitness as compared to the control group, specifically on the following tests: 50-meter running (p = 0.0044), toe touch (p = 0.0137), standing long jump (p = 0.0076), 4 × 10 m sprint (p = 0.0333), hand strength (p = 0.0233).

Conclusions

These results have shown long-term positive effects of the use of "Brainball" educational balls in physical education classes on the physical fitness development of students, especially in the qualities of speed, strength, and flexibility.

Lifestyle and physical fitness in adolescents with type 1 diabetes and obesity

Background

The association between Type 1 Diabetes Mellitus (T1DM) and obesity (Ob) is no longer unexpected due to unhealthy lifestyle mostly in adolescents. We compared clinical-biochemical characteristics, adherence to the Mediterranean Diet (MD), lifestyle habits and physical fitness across different weight categories of T1DM adolescents from Campania Region. As second aim, we assessed the relationship among lifestyle and physical fitness in these patients.

Methods

74 adolescents (35M; 39F; 13-18 y), with T1DM diagnosed at least 6 mo before the study, were enrolled at the Regional Center for Pediatric Diabetology of Vanvitelli University of Naples. Height, weight, Body Mass Index (BMI), BMI z-score, and Clinical Biochemical health-related parameters were determined. MD adherence, physical activity (PA) amount and sedentary habits were assessed by questionnaires. Handgrip strength, 2-Min Step test (2-MST) cardiorespiratory endurance and Timed up and go test (TUG) for agility and balance were used for physical fitness evaluation.

Results

Our sample included 22 normal weight (NW), 37 overweight (OW) and 15 with Obese (Ob) adolescents. Across the three groups, adolescents showed similar Clinical-Biochemical parameters, MD adherence, PA amount, mostly walking (9.3 h/w), daily video exposure (8.5 h/d) and similar handgrip or 2-MST performance. Better performance was observed in NW compared to OW or Ob for TUG (7 vs 8 vs 9 s; p < 0.05). A positive correlation was found between TUG test and BMI, while no correlation was found between HbA1c (glycated haemoglobin) and BMI z score or 2-MST.

Conclusions

T1DM adolescents did not meet the recommendations for active lifestyle, despite a medium/good adherence to MD, in particular in NW and OW youths. Sedentary habits correlated with a poor HbA1c. Further, reduced agility and balance were observed in adolescents with obesity compared to NW participants.Future research should be aimed to examine wider samples and to design health promotion interventions for T1DM adolescents.

A Meta-Analysis of Sampled Maximal Aerobic Capacity Data for Boys Aged 11 Years Old or Less Obtained by Cycle Ergometry

The aim of this study was to develop distributions of VO_2max based on measured values that exist in the literature in prepubertal boys using cycle ergometry. PRISMA guidelines were followed in conducting this research. One database was searched for peak and maximal VO₂ values in healthy boys with mean age under 11 years old. Data were split into articles reporting absolute and relative VO_2max values and analyzed accordingly. Multilevel models grounded in Bayesian principles were used. We investigated associations between VO_2max and body mass, year of the study, and country of origin. Differences in "peak" and "maximal" VO₂ were assessed. Absolute VO_2max (Lmin^-1) increases with age (P ~100%) but mean relative VO_2max does not change (P ~100%). Absolute VO_2max is higher in more recent studies (P = 95.7 ± 0.3%) and mean relative VO_2max is lower (P = 99.6 ± 0.1%). Relative VO_2max in the USA is lower compared with boys from other countries (P = 98.8 ± 0.2%), but there are no differences in absolute values. Mean aerobic capacity estimates presented as "peak" values are higher than "maximal" values on an absolute basis (P = 97.5 ± 0.3%) but not on a relative basis (P = 99.6 ± 0.1%). Heavier boys have lower cardiorespiratory fitness (P ≈ 100%), and body mass seems to be increasing faster with age in the USA compared with other countries (P = 92.3 ± 0.3%). New reference values for cardiorespiratory fitness are presented for prepubertal boys obtained with cycle ergometry. This is new, as no reference values have been determined so far based on actual measured values in prepubertal boys. Aerobic capacity normalized to body weight does not change with age. Cardiorespiratory fitness in prepubertal boys is declining, which is associated with increasing body mass over the last few decades. Lastly, this study did not find any statistically significant difference in the sample's mean aerobic capacity estimates using the "peak" and "maximum" distinctions identified in the literature.

Effect of Physical Activity/Exercise on Cardiorespiratory Fitness in Children and Adolescents with Type 1 Diabetes: A Scoping Review

The most common type of diabetes among children and adolescents is type 1 diabetes mellitus (T1DM), which is associated with an increased risk of cardiovascular disease (CVD). Additionally, lower levels of cardiorespiratory fitness (CRF) are linked to an increased risk of CVD. Regular exercise is associated with a decreased risk of CVD and improved CRF. We conducted this scoping review to assess the effects of exercise on CRF in youth with T1DM. Three electronic databases (PubMed, Embase, and Cochrane Central Register of Controlled Trials) were used to search for the relevant literature. In this analysis, the PICOS method was used to select studies and was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Guidelines scoping review guidelines for the evaluation of the effects of physical activity and cardiac function; the criteria may include the type and intensity of physical activity, the duration of the intervention, peak oxygen consumption (VO2), peak minute ventilation (VE), and peak heart rate of cardiorespiratory fitness. Screening resulted in 434 records. Of these, nine articles were included in our study. These nine studies were experimental (noncontrolled trials or randomized controlled trials) (n = 7) and observational (cross-sectional) (n = 2), and could be used to evaluate the effectiveness of physical activity interventions on cardiac function. The effects of exercise on CRF in youth with T1DM vary according to the type, frequency, and intensity of the exercise. According to our review, the duration of exercise included in the studies did not meet the recommendations of the guidelines for youth with T1DM. Additionally, half of the studies revealed that exercise could optimize the lipid profile in youth with T1DM. Hence, this research is to provide an overview of the effects of physical activity and exercise on CRF, cardiovascular fitness, lipid profile, and blood pressure in youth with T1DM, as well as identified potential limitations of the existing studies. Nevertheless, the limited number of clinical studies employing exercise interventions for children and adolescents with T1DM emphasize the need for more studies in this area, and more specific modes of exercise should be developed in the future.

Effects of a Physical Exercise Program and Health Advice on Sedentary Behavior of Adolescents

Sedentary behavior (SB) is a risk factor for chronic non-communicable diseases. This study aimed to assess the effects of an extracurricular physical exercise program and health advice on SB in adolescents. This was a non-randomized experimental study involving 19 adolescents divided into an intervention group (IG) and a control group (CG), aged 13-16 years from a public school in a Brazilian municipality. SB was measured using self-reports and accelerometers. The intervention included physical exercise and health advice. Repeated measures analysis of variance with a significance level of α = 5% was used. There was a time*group interaction for the subscapular fold ((pre IG = 16.30 mm vs. CG = 13.44 mm, post IG = 14.00 mm vs. CG = 15.89 mm) p = 0.001), and VO2MAX ((pre IG = 32.75 mL/kg/min vs. CG = 30.66 mL/kg/min, post IG = 35.76 mL/kg/min vs. CG = 29.28 mL/kg/min) p = 0.008). The accelerometer showed significant differences between groups in the total SB ((pre IG = 647.49 min/day vs. CG = 535.24 min/day, post IG = 614.02 min/day vs. CG = 586.97 min/day) p = 0.045), with a significant decrease in the IG. In conclusion, an extracurricular physical exercise program and health advice was effective in reducing SB in adolescents.

The association between muscle strength and executive function in children and adolescents: Based on survey evidence in rural areas of China

Background

In recent years, muscle strength in children and adolescents has continued to decline, especially in rural areas. Executive function as a higher function of the brain, is closely related to the future achievement of children and adolescents. For this reason, this study analyzed the correlation between muscle strength and executive function in children and adolescents in rural areas of China to better promote the development of muscle strength and executive function.

Methods

Demographic factors, muscle strength, and executive function were tested in 1,335 children and adolescents in rural China using a three-stage stratified whole-group sampling method. One-way ANOVA and chi-square test were used to compare the differences in executive function among children and adolescents with different muscle strengths. Multiple linear regression analysis and logistic regression analysis were used to analyze the association that exists between muscle strength and executive function.

Results

When comparing the inconsistently, congruent, 1back, 2back, conversion, size parity, and cognitive flexibility response times of children and adolescents with different muscle strength indexes in rural China, the differences were statistically significant (F = 46.592, 45.610, 10.809, 32.068, 24.095, 19.260, 11.501, p < 0.001). Logistic regression analysis was performed using children and adolescents with muscle strength index >P80 as the control group. The results showed that the risk of 1back dysfunction was higher (OR = 1.764, 95% CI:1.094, 2.843) in children and adolescents with muscle strength index <P20 (p < 0.05). The risk of 2back dysfunction was higher in children and adolescents with a muscle strength index <P20 (OR = 2.129, 95% CI:1.329, 3.410) (p < 0.01). Compared with children and adolescents with muscle strength index >P80. The muscle strength index <P20 group had a higher risk of cognitive flexibility dysfunction (OR = 1.820, 95% CI:1.111, 2.982) (p < 0.05).

Conclusion

There is a association between muscle strength and executive function in children and adolescents in rural areas of China. Those with higher muscle strength have shorter executive function reaction times and are at lower risk of developing executive dysfunction. Future measures should be taken to improve muscle strength and executive function levels in children and adolescents in rural areas to promote healthy physical and mental development.

Secular trends of cardiorespiratory fitness in children and adolescents over a 35-year period: Chronicle of a predicted foretold

Background

In the context of concerns regarding the cardiorespiratory fitness (CRF) of youth populations, the aims of this study were: (1) to update reference values for the VO₂max for school-aged Canadians and (2) to document secular trends in CRF after a 35-year interval.

Methods

Between September 2014 and April 2017, the CRF of 3725 students (53.2% boys; 6.0 to 17.9 yrs) was determined using the 20-m shuttle run test. The sample was collected in 36 different schools from six cities of Québec (Canada).

Results

Median values of VO₂max decreased with age in both sexes (p ≤ 0.05). By the age of 10, more than 20% of boys showed VO₂max values below the recommended value (42 ml·kg^-1·min^-1). At the age of 17, that proportion reached 56.8%. A similar proportion of 12 yrs girls (20%) were under the recommended minimal value (37 ml·kg^-1·min^-1) and that value reached 69.9% at the age of 17. Compared to 1982, the VO₂max at age 17 has declined by 18% for boys and 12% for girls. The situation is worse in terms of functional capacity (number of stages completed) with an overall decrease of more than 30%.

Conclusion

This study demonstrates that, compared to data obtained using the same methodology 35 years ago, the CRF and functional capacity of children and adolescents has declined to levels that should raise concerns from a public health perspective. Thus, the development of strategies to promote a physically active lifestyle in youth is more relevant than ever.

An Investigation of the Utility of Waist Circumference Predicting Cardiorespiratory Fitness in School Children: A Cross-Sectional Study

The early identification of modifiable risk factors and their monitoring, also within school physical education (PE) classes, are becoming indispensable in the context of public health. The aim of this study was to test whether making use of waist circumference (WC) measurements increases the possibility of predicting the results of cardiorespiratory fitness (CRF) in school-age children, as compared with body mass index (BMI) and other somatic indicators related to body fat. The cross-sectional study covered 190 children aged 10 to 15 years, participating in school PE classes. Body height (BH), body weight (BW), WC, hip circumference (HC) and percentage of body fat (BF%) were measured. BMI, waist to hip ratio (WHR) and waist to height ratio (WHtR) were calculated, and a CRF test was performed by means of a 20 m shuttle run test (20mSRT). The peak heart rate (HR_peak) of the children was also measured. The regression model that was developed showed that WC (R² = 47.1%), beyond BF% (R² = 50.3%) and WHtR (R² = 50.0%), was a useful measure of CRF, and stronger than BMI (R² = 45.8%) or WHR (R² = 39.2%). The risk of obtaining the CRF result classified below a good level (below the percentile range of P60-P80) was significantly higher in children with a larger WC (odds ratio (OR) for the WC change of 1 cm equals 1.14 (95% CI: 1.09-1.20; p < 0.001)). The simplicity of measuring WC and the possibility of using this measurement in the calculation of WHtR with reference to CRF indicate its usefulness in the prophylactic exams of school children.

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 (β =  -0.031, p = 0.025), while absolute CRF was positively associated with Met4 in male children and adolescents (β = 0.000, p < 0.05). Relative upper and lower-body MF were longitudinally and negatively associated with Met4 in female adolescents (β =  -1.347, β =  -0.005, p < 0.05), while absolute lower-body MF was positively associated with Met4 in male children (β = 0.000, p = 0.019). BC was longitudinally and positively associated with Met4 in male children (β-ranging from 0.011 to 0.055, all p < 0.05) and male adolescents (β-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.

Association Between Physical Activity, Sedentary Behavior and Physical Fitness and Glycated Hemoglobin in Youth with Type 1 Diabetes: A Systematic Review and Meta-analysis

BACKGROUND

Scientific literature suggests poor glycemic control in youth with type 1 diabetes (T1D) and physical inactivity, sedentary behavior and low physical fitness levels, although results are not entirely consistent.

OBJECTIVE

To meta-analyze the association between glycated hemoglobin and physical activity, sedentary behavior, and physical fitness in children and adolescents with T1D.

METHODS

Our meta-analysis was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Guidelines (PRISMA). Three databases were searched for studies. All studies meeting the following criteria were included: (1) Population: children and adolescents with a mean age between 3 and 18 years diagnosed with T1D; (2) Exposition: physical activity and/or sedentary behavior and/or cardiorespiratory fitness and/or muscular fitness; (3) Outcome: glycated hemoglobin; (4) Study design: cross-sectional, longitudinal, and case-control studies. Pooled effects were calculated using a random effects inverse-variance model with the Hartung-Knapp-Sidik-Jonkman adjustment.

RESULTS

Thirty-seven studies were included, accounting for a total of 34,863 youths with T1D (51.9% girls). Twenty-nine studies evaluated physical activity, eight sedentary behavior, 14 cardiorespiratory fitness, and two muscular fitness. A negative association between physical activity (r = - 0.09, 95% CI - 0.14 to - 0.04; I² = 63.5%), cardiorespiratory fitness (r = - 0.31, 95% CI - 0.44 to - 0.19; I² = 57.0%) and glycated hemoglobin was found. Also, the association with sedentary behavior was positive (r = 0.20, 95% CI 0.04 to 0.35; I² = 92.6%). All the associations were independent of the glycated hemoglobin levels and diabetes duration.

CONCLUSIONS

Low levels of physical activity and cardiorespiratory fitness and extensive sedentary behavior may explain part of the variance in glycated hemoglobin and part of the risk for poor glycemic control in youth with T1D.

PROSPERO

Registration number: CRD42021254362.

Top 10 International Priorities for Physical Fitness Research and Surveillance Among Children and Adolescents: A Twin-Panel Delphi Study

BACKGROUND

The measurement of physical fitness has a history that dates back nearly 200 years. Recently, there has been an increase in international research and surveillance on physical fitness creating a need for setting international priorities that could help guide future efforts.

OBJECTIVE

This study aimed to produce a list of the top 10 international priorities for research and surveillance on physical fitness among children and adolescents.

METHODS

Using a twin-panel Delphi method, two independent panels consisting of 46 international experts were identified (panel 1 = 28, panel 2 = 18). The panel participants were asked to list up to five priorities for research or surveillance (round 1), and then rated the items from their own panel on a 5-point Likert scale of importance (round 2). In round 3, experts were asked to rate the priorities identified by the other panel.

RESULTS

There was strong between-panel agreement (panel 1: r_s = 0.76, p < 0.01; panel 2: r_s = 0.77, p < 0.01) in the priorities identified. The list of the final top 10 priorities included (i) "conduct longitudinal studies to assess changes in fitness and associations with health". This was followed by (ii) "use fitness surveillance to inform decision making", and (iii) "implement regular and consistent international/national fitness surveys using common measures".

CONCLUSIONS

The priorities identified in this study provide guidance for future international collaborations and research efforts on the physical fitness of children and adolescents over the next decade and beyond.

Physical fitness mediates and predicts for high blood pressure among children in relation to weight status

Background

Pediatric hypertension contributes to adulthood hypertension and target organ damage. Obesity is a well-known predictor for pediatric hypertension; however, the relationship between physical fitness and blood pressure (BP) is unclear among children. This study aimed to compare the differences in demographics, anthropometrics, and physical fitness across BP subgroups and investigate whether physical fitness was related to pediatric hypertension independent of weight status.

Methods

This quantitative, cross-sectional study investigated demographic, anthropometric, physical fitness, and BP measures among 360 healthy school-aged children. Continuous variables were compared across BP subgroups with the one-way analysis of variance. Mediation and moderation analyses were used to explore the mechanism. Multivariable regression models were used to assess independent associations for hypertension.

Results

There were 177 (49.2%), 37 (10.3%), and 146 (40.6%) children in the normotensive, elevated BP, and hypertensive subgroups, respectively. The hypertensive subgroup had higher body mass index (BMI) and waist/height ratio percentiles and performed worse in 800-m run, standing long jump (SLJ), and 1-min sit-ups than the normotensive subgroup. Furthermore, the 800-m run percentile (total effect: β = 0.308, standard error = 0.044, p < 0.001) and sit and reach percentile (total effect: β = 0.308, standard error = 0.044, p < 0.001) mediated the relationship between the BMI percentile and systolic BP percentile; the SLJ percentile was directly associated with the diastolic BP percentile (β,-0.197, 95% confidence interval,-0.298-0.097; p < 0.001). The parsimonious model of multivariable regression models revealed that the SLJ percentile (adjusted exp (β), 0.992, 95% confidence interval, 0.985-0.999; p = 0.042) and BMI percentile (adjusted exp (β), 1.024, 95% confidence interval, 1.016-1.032; p < 0.001) were two independent predictors for pediatric hypertension.

Conclusion

Physical fitness mediates the relationship between anthropometric and BP measures. The SLJ percentile is associated with pediatric hypertension independent of the BMI percentile. Proactive screening and health promotion for not only healthy weight status but also good physical fitness may be beneficial for BP control among school-aged students.

Physical activity and physical fitness in children with heritable connective tissue disorders

Objectives

Health problems in patients with heritable connective tissue disorders (HCTD) are diverse and complex and might lead to lower physical activity (PA) and physical fitness (PF). This study aimed to investigate the PA and PF of children with heritable connective tissue disorders (HCTD).

Methods

PA was assessed using an accelerometer-based activity monitor (ActivPAL) and the mobility subscale of the Pediatric Evaluation of Disability Inventory Computer Adaptive Test (PEDI-CAT). PF was measured in terms of cardiovascular endurance using the Fitkids Treadmill Test (FTT); maximal hand grip strength, using hand grip dynamometry (HGD) as an indicator of muscle strength; and motor proficiency, using the Bruininks-Oseretsky Test of Motor Proficiency-2 (BOTMP-2).

Results

A total of 56 children, with a median age of 11.6 (interquartile range [IQR], 8.8-15.8) years, diagnosed with Marfan syndrome (MFS), n = 37, Loeys-Dietz syndrome (LDS), n = 6, and genetically confirmed Ehlers-Danlos (EDS) syndromes, n = 13 (including classical EDS n = 10, vascular EDS n = 1, dermatosparaxis EDS n = 1, arthrochalasia EDS n = 1), participated. Regarding PA, children with HCTD were active for 4.5 (IQR 3.5-5.2) hours/day, spent 9.2 (IQR 7.6-10.4) hours/day sedentary, slept 11.2 (IQR 9.5-11.5) hours/day, and performed 8,351.7 (IQR 6,456.9-1,0484.6) steps/day. They scored below average (mean (standard deviation [SD]) z-score -1.4 (1.6)) on the PEDI-CAT mobility subscale. Regarding PF, children with HCTD scored well below average on the FFT (mean (SD) z-score -3.3 (3.2)) and below average on the HGD (mean (SD) z-score -1.1 (1.2)) compared to normative data. Contradictory, the BOTMP-2 score was classified as average (mean (SD) z-score.02 (.98)). Moderate positive correlations were found between PA and PF (r(39) = .378, p < .001). Moderately sized negative correlations were found between pain intensity and fatigue and time spent actively (r(35) = .408, p < .001 and r(24) = .395 p < .001, respectively).

Conclusion

This study is the first to demonstrate reduced PA and PF in children with HCTD. PF was moderately positively correlated with PA and negatively correlated with pain intensity and fatigue. Reduced cardiovascular endurance, muscle strength, and deconditioning, combined with disorder-specific cardiovascular and musculoskeletal features, are hypothesized to be causal. Identifying the limitations in PA and PF provides a starting point for tailor-made interventions.

Normative values of cardiorespiratory fitness in Croatian children and adolescents

Although defining normative values of cardiorespiratory fitness have been the topic of many Western societies, little evidence has been provided for less developed countries like Croatia. Since cardiorespiratory fitness rapidly declines in Croatian children and adolescents, the newly established normative values would help health-related professionals and physical education teachers to detect 'talented' groups and direct them towards sport and 'risky' groups for planning special interventions. Therefore, the main purpose of the study was to determine normative reference values of cardiorespiratory fitness. A total of 1,612 children and adolescents aged 7-14 years (mean±SD; age 9.7±2.4 years; stature 151.0±17.6 cm; body mass 45.1±19.1 kg; 52.5% girls) participated in this cross-sectional study. Cardiorespiratory fitness was assessed by the Maximal multistage 20-m shuttle run test and the performance was expressed as the number of stages. Maximal oxygen uptake (VO2max) was estimated by equations. Smoothed percentile curves were calculated. Boys outperformed girls in the maximal number of levels achieved after the 20-m shuttle run test and in the VO2max values at each age category. In boys, a gradually higher level of performance between ages 11 and 14 was observed, while in girls the values started to rise after the age of 8. Our study provides one of the first sex- and age-specific normative values for cardiorespiratory fitness assessed by the 20-m shuttle run test in Croatian children and adolescents.

Relevance and Effectiveness of Combined Resistance and Balance Training to Improve Balance and Muscular Fitness in Healthy Youth and Youth Athletes: A Scoping Review

BACKGROUND

Balance and resistance training applied as single-mode interventions have proven to enhance measures of balance and/or muscular fitness in youth and youth athletes. Less is known on the effectiveness of combined or sequenced balance and resistance training in youth and youth athletes.

OBJECTIVE

The objective of this scoping review was to describe the effects of concurrently performed balance and resistance training (i.e., metastable resistance training) and different sequencing schemes of balance and resistance training on measures of balance and/or muscular fitness in healthy youth and youth athletes. We additionally aimed to identify knowledge gaps in the literature.

METHODS

According to the principles of a scoping review, we followed a broad research question, identified gaps in the literature, and reported findings on the level of single studies but did not aggregate and meta-analyze outcomes across studies. For this purpose, systematic literature searches were conducted in the electronic databases PubMed (including MEDLINE), Web of Science, and SPORTDiscus from inception until August 2022. We included metastable resistance training and sequenced balance and resistance training studies in healthy youth and youth athletes aged 6-18 years that investigated the training-induced effects on measures of balance (e.g., stork balance test) and muscular fitness (e.g., countermovement jump test) in contrast to active/passive controls. The Physiotherapy Evidence Database (PEDro) scale was used to assess the risk of bias. The Strength of Recommendation Taxonomy (SORT) was applied for the whole scoping review on levels A (high strength of recommendation) to C (low strength of recommendation) and for individual studies on levels 1 (high-quality evidence) to 3 (low-quality evidence).

RESULTS

The strength of recommendation for the scoping review was level B based on inconsistent or limited-quality evidence. Eleven randomized controlled trials were eligible to be included in this scoping review and each study was rated as 'limited-quality evidence'. A median PEDro score of 6 was computed across the included studies. Four studies examined the effects of metastable resistance training (e.g., plyometric training on unstable surfaces) on measures of balance and/or muscle fitness in youth athletes. The remaining seven studies investigated the impact of sequenced balance and resistance training (e.g., blocked balance training followed by blocked resistance training) on measures of balance and/or muscle fitness in youth and youth athletes. The duration of the intervention programs ranged from 6 to 10 weeks with 2-weekly to 3-weekly exercise sessions. Participants' age range was 10-18 years (mean 15 years). Ten studies examined young male and female athletes from different sports (i.e., basketball, handball, soccer) and one study physical education students. Metastable resistance training compared with plyometric training performed on stable surfaces showed no extra effect on measures of balance and muscular fitness. Stable plyometric training appears to be even more effective to improve jump performance. Sequenced balance and resistance training in the form of a mesocycle of balance followed by plyometric training seems to be particularly effective to improve measures of balance and muscular fitness in young athletes. This scoping review identified knowledge gaps that may indicate future research avenues: (i) comparative studies should be designed to examine how sex, age, maturity status, and expertise level impact on the adaptive potential following metastable resistance training or sequenced balance and resistance training in youth and youth athletes, (ii) at least one established measure of balance and muscular fitness should always be included in study designs to allow future comparison between studies and to aggregate (meta-analyze) findings across studies and (iii) studies are needed that examine neuromuscular and tendomuscular adaptations following these exercise types as well as dosage effects.

CONCLUSIONS

According to the results of this scoping review, balance training should be an essential training component for youth that is incorporated with the resistance training exercises or introduced at least a month before resistance and plyometric training within a periodized training program. More research is needed to examine the moderating roles of age, maturity status, and sex.

Effects of fundamental movement skills on health-related quality of life in Chinese school-age children: the mediating role of physical fitness level

Background

The primary purpose of this study is to analyze the relationship between school-age children's fundamental movement skills (FMS), physical fitness levels, and the health-related quality of life (HRQoL); To explore the mediating role of physical fitness levels between school-age children's FMS and HRQoL.

Methods

In the cross-sectional survey in 2021, 334 school-age children aged 6-10 (8.20 ± 1.16) were recruited from primary schools in Jinhua City, Zhejiang Province, China. Test of Gross Motor Development 2 (TGMD-2), National Standards for Students' Physical Health, and Pediatric Quality of Life Inventory TM Version 4.0 (PedsQL™ 4.0) were used to investigate the FMS, physical fitness level, and HRQoL of school-age children. Hierarchical regression was used to analyze the relationship among FMS, physical fitness levels, and HRQoL. Bootstrap is used to evaluate the mediating role of physical fitness levels in the relationship between FMS and HRQoL.

Results

The higher the FMS and physical fitness, the higher the school-age children's HRQoL, physical functioning, social functioning, and school functioning (r = 0.244-0.301, p < 0.01). In addition, developing children's FMS promotes physical fitness levels (r = 0.358, p < 0.01). The regression analysis results of controlling gender, age, and body mass index z (BMI-z) scores showed that FMS significantly positively predicted the physical functioning (β = 0.319, p < 0.01), social functioning (β = 0.425, p < 0.01), and school functioning (β = 0.333, p < 0.01) of school-age children. When the physical fitness level enters the regression equation, the absolute value of the regression coefficient of FMS decreases. However, it can still significantly predict the physical functioning (β = 0.211, p < 0.01) and school functioning (β = 0.142, p < 0.05) of school-age children. Simple intermediary analysis shows that physical fitness level plays an intermediary role between FMS, physical functioning (indirect effect = 0.089 [95% Confidence interval (CI) = 0.015,0.195]), and school functioning (indirect effect = 0.065 [95% CI = 0.007,0.150]).

Conclusion

This study shows that physical fitness levels mediate the relationship between FMS and HRQoL. Encouraging the development of FMS and promoting physical fitness levels of school-age children can effectively improve the HRQoL of school-age children.

Are anthropometric characteristics powerful markers to predict the Cooper Run Test? Actual Caucasian data

Background

Cardiorespiratory fitness (CRF) is a powerful marker of cardiovascular health, especially in youth. Several field tests can provide accurate measurement of CRF, the Cooper Run Test (CRT) is generally preferred by physical education (PE) teachers and trainers. The CRT performance in adolescents has been compared to reference distance values, gender and age but the differences among the anthropometric characteristics of youth has not been evaluated. For these reasons, the aim of this study was to develop reference standards for CRT and evaluate possible correlations between biometric measurements and athletic performance.

Methods

This cross-sectional study involved a total of 9,477 children (4,615 girls) aged 11-14 years, freely recruited from North Italian middle schools. Mass, height and CRT performances were assessed in the morning during PE classes as scheduled (mornings-Monday to Friday). The anthropometric measures were collected at least 20 min before the CRT run test.

Results

We found a better CRT result in boys (p < 0.001), however a smaller SD in girls suggested a more homogeneous aerobic performance for girls (i.e., 371.12 m vs 282.00 m). In addition, the Shapiro-Wilk test showed a low p-value (p < 0.001) but the effect size (0.031 for boys and 0.022 for girls) was small enough that the correction on this parameter allows a practical assumption of normality for the distributions. A visual homoskedastic distribution in both sexes is evident for both body mass index (BMI), mass and VO₂ peak with respect to CRT results. In addition, there were low linear correlation coefficients for both BMI, mass and VO₂ peak compared to the CRT results, with a R2 < 0.5 for every covariate. The only visual heteroskedastic distribution was observed in regression between distance in CRT and age at peak high velocity.

Conclusions

Our findings suggested that anthropometric characteristics are not powerful markers to predict Cooper Run Test results in a well-mixed, unpolarized and unbiased pool of middle school boys and girls. PE teachers and trainers should prefer endurance tests over the use of indirect formulas to predict performance.

Effectiveness of an adapted physical activity intervention on health-related physical fitness in adolescents with intellectual disability: a randomized controlled trial

This study aimed to examine the effects of an adapted physical activity (APA) intervention on health-related physical fitness (HRPF) in adolescents with intellectual disability (ID). With a randomized controlled trial design, adolescents aged 12-18 years, with mild and moderate ID, and being overweight and obese were recruited and randomly assigned to either an intervention or a control group. The APA intervention consisted of overall moderate intensity aerobic and resistance exercise, with a duration of 45 min/session, a frequency of 2 sessions/week, and lasting for 9 months. A negative control was involved, in which participants received no treatment. Changes in four fitness tests, including the 9-min run/walk, handgrip strength, 30-s sit-ups, and sit-and-reach tests, were assessed between the groups using general linear models. A total of 57 participants (39 in the intervention group and 18 in the control group) completed the study. Significant mean differences in changes in the 9-min run/walk test (413.6 m [95% CI 146.72 m, 680.41 m], p = 0.003) and the right-side sit-and-reach test (2.2 cm [95% CI 0.37 cm, 4.09 cm], p = 0.020) respectively were observed in the intervention group, compared to the control group. No significant between-group improvement was observed for the handgrip strength and the 30-s sit-ups tests. The APA intervention induced beneficial effects on cardiorespiratory fitness and potential beneficial effects on flexibility for adolescents with ID. However, no significant effects of this intervention on muscular strength and endurance were observed in this study. Future studies should consider involving effective exercises in interventions to improve muscular strength and endurance.

Association Analyses of Physical Fitness Parameters and Anxiety Symptoms in Chinese College Students

Poor physical fitness is related to many negative health outcomes, including mental disorders. However, the relationship between physical fitness and anxiety symptoms among college students remains unclear. Therefore, this study investigated whether physical fitness is related to anxiety symptoms in Chinese college students. Cross-sectional data were collected from 6635 men and 4482 women. Physical fitness was measured via a 50-m sprint, a sit-and-reach test, vital capacity, and a standing long jump for both sexes; 1000-m run and pull-up tests for males; and 800-m run and sit-up tests for females. The seven-item Generalized Anxiety Disorder Scale (GAD-7) was used to evaluate anxiety symptoms. Multivariate linear regression showed that better physical fitness was related to lower GAD-7 scores. In addition, multivariate logistic regression analysis showed that better ability in the 50-m sprint, sit-and-reach test, pull-up test, and vital capacity was related with a lower risk of anxiety symptoms in males, and better ability in the 800-m run and standing long jump was related with a lower risk of anxiety symptoms in females. In conclusion, physical fitness was inversely associated with anxiety symptoms in male and female college students. This association was also independent of confounding factors.

Physical Fitness Perception and Physical Education Enjoyment in 11- to 12-Year-Old Children

Childhood motor competence plays a fundamental role in long-term adherence to physical activity. Enjoyment levels and self-perception of physical fitness increase motivation, commitment, and participation in physical activity. The objective of this study was to assess the body mass index (BMI), weight percentile, health status, physical fitness, and enjoyment levels of physical activity. A sample of 138 persons, of whom 67 were males and 71 females, with a mean BMI of 20.04 (2.35) answered the questionnaires Physical Activity Enjoyment Scale and the International Fitness Scale−self-report of physical fitness in young people. Tests were administered to measure functional fitness and anthropometric characteristics. Statistical analysis included calculation of Cronbach’s alpha, ANOVA and Pearson’s bivariate test correlations. The data indicate the reliability of the International Fitness Scale. No significant differences by gender were observed for the Physical Activity Enjoyment Scale. The BMI showed that significant positive correlations with 20 m sprint scores (p < 0.001, r = 0.367) and significant negative correlations with 6-minute lap scores (p < 0.001, r = −0.360) could be caused by an older physiological age. The overall physical fitness level of the children was medium-high, with most of the children enjoying physical education classes and slightly higher enjoyment values for males 40.88 (5.42) than females 40.31 (6.16).

Effect of resistance circuit training on health-related physical fitness, plasma lipid, and adiponectin in obese college students

The purpose of this study is to investigate the effects of resistance circuit training on health-related physical fitness, plasma lipid and adiponectin in obese college students. Twenty male college students participated in this study and they were randomly divided into the sedentary group (SG, n=10) and the resistance circuit training group (RCG, n=10). The exercise group underwent the resistance circuit training program for 60 min 3 times a week for 12 weeks, while the sedentary group continued activities of daily living as usual. The levels of health-related fitness, blood lipid, and adiponectin were measured twice before and after the experiment. To analyze the statistically significance of collected data, Two-way repeated measure analysis of variance was used to determine the changes in the groups over the training period. A paired t-test was used to verify the difference within each group, and an independent t-test was used to verify the difference between the groups. In this study, the body composition including body fat mass, percent body fat and body mass index were significantly decreased in RCG compared to those in SG, and the health-related fitness showed a significant difference between RCG and SG. In addition, RCG positively modulated blood concentration of total cholesterol, triglycerides, high-density and low-density lipoprotein cholesterol. However, plasma adiponectin concentration did not show any significant differences between the two groups. Therefore, the present data suggested that resistance circuit training might be regulator to improve health-related physical fitness and decrease the level of plasma lipid in obese male college students.

Relationship between health-related quality of life and physical fitness in Norwegian adolescents

AIMS

This cross-sectional study investigated the association between health-related quality of life (HRQoL), cardiorespiratory fitness (CRF) and muscular fitness in 14-year-old adolescents.

METHODS

Norwegian adolescents (N = 1985) carried out a 10-min running test to assess cardiorespiratory fitness and three different muscular fitness tests (handgrip, sit-ups, and standing broad jump) and answered the KIDSCREEN-27 questionnaire to provide HRQoL data. Linear-mixed effect models were applied to detect relationships among the variables.

RESULTS

Running-test results were positively associated with higher scores in the following KIDSCREEN domains: physical well-being, psychological well-being, autonomy and parent relationships, and school environment (β = 0.01-0.04; p < .01 for all). Performance in sit-ups test was positively associated with higher scores in three out of five KIDSCREEN domains: physical well-being (β = 0.31; p < .001), social support and peers (β = 0.16; p = .023), and school environment scores (β = 0.19; p = .006). An inverse association was found between the handgrip test results and the score on psychological well-being domain (β = - 0.10; p = .013).

CONCLUSIONS

The associations between HRQoL and physical fitness were trivial (abdominal strength and handgrip strength) to small (CRF) but confirmed that earlier findings from children also are applied to adolescents. Explosive strength in the lower body showed no association with HRQoL. Further research should investigate the direction of causality.

TRIAL REGISTRATION

Clinicaltrials.gov ID nr: NCT03817047. Registered 01/25/2019 'retrospectively registered'.

Portuguese Physical Literacy Assessment - Observation (PPLA-O) for adolescents (15-18 years) from grades 10-12: Development and initial validation through item response theory

Introduction

Aims of these studies were to develop the Portuguese Physical Literacy Assessment Observation instrument (PPLA-O) to assess the physical and part of the cognitive domain of Physical Literacy (PL) through data collected routinely by Physical Education (PE) teachers; and to assess the construct validity (dimensionality, measurement invariance, and convergent and discriminant validity) and score reliability of one of its modules [Movement Competence, Rules, and Tactics (MCRT)].

Methods

Content analysis of the Portuguese PE syllabus and literature review were used for PPLA-O domain identification. Multidimensional Item Response Theory (MIRT) models were used to assess construct validity and reliability, along with bivariate correlations in a sample of 515 Portuguese grade 10-12 students (M age = 16, SD = 1).

Results

PPLA-O development resulted in an instrument with two modules: MCRT (22 physical activities) and Health-Related Fitness (HRF; 5 protocols); both assessed with teacher-reported data entered in a spreadsheet. A two correlated dimensions Graded Response Model (Manipulative-based Activities [MA], and Stability-based Activities [SA]) showed best fit to the MCRT data, suggesting measurement invariance across sexes, and adequate to good score reliabilities (MA = .89, and SA = .73). There was a moderate to high correlation (r = .68) between dimensions, and boys had higher scores in both dimensions. Correlations among MCRT scores and HRF variables were similar in magnitude to previous reports in meta-analysis and systematic reviews.

Conclusions

PPLA-O is composed of two modules that integrate observational data collected by PE teachers into a common frame of criterion-referenced PL assessment. The HRF module uses data collected through widely validated FITescola® assessment protocols. The MCRT makes use of teacher-reported data collected in a wide range of activities and movement pursuits to measure movement competence and inherent cognitive skills (Tactics and Rules). We also gathered initial evidence supporting construct validity and score reliability of the MCRT module. This highly feasible instrument can provide Portuguese grade 10-12 (15-18 years) PE students with feedback on their PL journey, along with the other instrument of PPLA (PPLA-Questionnaire). Further studies should assess inter and intra-rater reliability and criterion-related validity of its two modules.

Role of aerobics exercise and kettlebell training improving on selected health related physical fitness parameters in obese male adults

Background: Aerobics exercise training and kettlebell training is recommended to prevent and control overweight/obesity.   Purpose: The aim of the this research is to assess the improvement in various variables related to health fitness among obese adults on administrating a twelve weeks aerobics exercise training and kettlebell training. Materials and Methods: Total sixty male adults with obese (Mean ± SD; age: 18.92 ± 1.54 yrs.; height: 172.4 ± 5.4 cm.; weight: 84.4 ± 6.3 kg) were randomly allocated into three equal (n = 20) groups: Aerobic Exercise Training (AET), Kettlebell Training (KBT) and a control group. The AET & KBT training protocol was performed three days per week for 12 weeks. All the selected variables of physical fitness has been examined at baseline and 12 weeks.   Control group does not perform any exercise. Analysis and findings: There were significant difference in terms of Flexibility (F), Muscular Endurance (ME), Muscular Strength (MS) and Cardiovascular Endurance (CE), between the AETG & KBTG have been compared with control group (p < 0.05).  Body Composition (BF) significant reductions in AET & KBT groups have been compared with control group (p < 0.05). Conclusion: Our findings suggest that AET & KBT protocols have greater effects than control group on health related physical fitness variables in obese male adult individuals. It is recommended that schools and colleges should administrate the aerobic exercise session and kettlebell training among adults for better health perspectives.

Predicting VO2max in Children and Adolescents Aged between 6 and 17 Using Physiological Characteristics and Participation in Sport Activities: A Cross-Sectional Study Comparing Different Regression Models Stratified by Gender

Background: The aim of this study is to use different regression models to capture the association between cardiorespiratory fitness VO2max (measured in mL/kg/min) and somatometric characteristics and sports activities and making better predictions. Methods: multiple linear regression (MLR), quantile regression (QR), ridge regression (RR), support vector regression (SVR) with three different kernels, artificial neural networks (ANNs), and boosted regression trees (RTs) were compared to explain and predict VO2max and to choose the best performance model. The sample consisted of 4908 children (2314 males and 2594 females) aged between 6 and 17. Cardiorespiratory fitness was assessed by the 20 m maximal multistage shuttle run test and maximal oxygen uptake (VO2max) was calculated. Welch t-tests, Mann−Whitney-U tests, X2 tests, and ANOVA tests were performed. The performance measures were root mean square error (RMSE), mean absolute error (MAE), and coefficient of determination (R2). All analyses were stratified by gender. Results: A comparison of the statistical indices for both the predicted and actual data indicated that in boys, the MLR model outperformed all other models in all indices, followed by the linear SVR model. In girls, the MLR model performed better than the other models in R2 but was outperformed by SVR-RBF in terms of RMSE and MAE. The overweight and obesity categories in both sexes (p < 0.001) and maternal prepregnancy obesity in girls had a significant negative effect on VO2max. Age, weekly football training, track and field, basketball, and swimming had different positive effects based on gender. Conclusion: The MLR model showed remarkable performance against all other models and was competitive with the SVR models. In addition, this study’s data showed that changes in cardiorespiratory fitness were dependent, to a different extent based on gender, on BMI category, weight, height, age, and participation in some organized sports activities. Predictors that are not considered modifiable, such as gender, can be used to guide targeted interventions and policies.

Longitudinal association of childhood physical activity and physical fitness with physical activity in adolescence: insights from the IDEFICS/I.Family study

BACKGROUND

This study aimed to examine associations of early childhood physical fitness and physical activity (PA) with PA during later childhood/early adolescence while accounting for gender differences.

METHODS

We selected data of N = 4329 children from the IDEFICS/I. Family cohort (age 2.4-11.7 years) with data on baseline fitness and accelerometer measurements. At baseline, physical fitness tests were conducted including Flamingo balance, Backsaver sit and reach, Handgrip strength, Standing Long Jump, 40-m sprint and 20-m Shuttle run (to estimate cardio-respiratory fitness levels). PA was measured with Actigraph accelerometers over 3 days at baseline (ActiTrainer or GT1M) and 7 days at follow-up (GT3X). Evenson cutpoints were used to determine moderate-to-vigorous PA (MVPA) time, and children with ≥60mins/day of average MVPA were deemed as having met WHO guidelines at baseline and follow-up. Linear and logistic regressions were performed to examine longitudinal associations between meeting WHO guidelines, MVPA, and physical fitness tests at baseline with meeting WHO guidelines and MVPA at follow-up. Models were conducted on the entire sample, the sex-stratified sample, and stratified by sex and pubertal status at follow-up.

RESULTS

Results showed that meeting WHO guidelines for MVPA at baseline was positively associated with MVPA (Standardized Beta (B) = 0.13, 95%CI:(5.6;11.1)) and meeting WHO guidelines at follow-up for the entire sample (OR = 2.1, 95%CI:(1.5; 3.14), and stratified by males (OR = 2.5, 95%CI:(1.5; 4.1)) and females (OR = 1.8, 95%CI:(1.0; 3.2)). This was also found for both male pre/early pubertal and pubertal groups but only in the female pre/early pubertal group, and not the female pubertal group (MVPA: B = .00, 95%CI:(- 6.1; 5.6), WHO: OR = 0.61, 95%CI:(0.23;1.6)). Models indicated that Standing Long jump, 40-m sprint, Shuttle run and Flamingo balance at baseline were associated with MVPA and meeting the guidelines at follow-up.

CONCLUSIONS

Meeting WHO guidelines and certain fitness tests at baseline were strongly associated with MVPA and meeting WHO guidelines at follow-up, but this association varied with sex and pubertal status. Consequently, these findings underline the importance of ensuring sufficient physical activity in terms of quality and quantity for children at the earliest stages of life.

TRIAL REGISTRATION

ISRCTN62310987.

Comparison of Cardiorespiratory Fitness of Chinese Tibetan Adolescents with Their Han Counterparts: A Cross-Sectional Retrospective Study

Cardiorespiratory fitness (CRF) is a core element of healthy physical fitness. Foreign attention to CRF in adolescents at different altitudes is high, while less research has been conducted on Chinese adolescents. In order to compare the CRF of Chinese Tibetan adolescents with their Han counterparts born and raised at high altitude and Chinese Han adolescents at sea level. A total of 2748 participants, including Chinese Tibetan adolescents, Chinese Han adolescents born and raised at high altitudes, and Chinese Han adolescents at sea level aged 12-18 years old, were obtained using convenience sampling and random cluster sampling. The method of the 20 m shuttle run test (20 m SRT) test was used to derive VO_2max by equation. One-way ANOVA and LSD methods were conducted, and effect sizes were calculated to compare the CRF of the three types of adolescents. Regression analysis was used to analyze the relationship between altitude and VO_2max. The VO_2max scores of Chinese Tibetan adolescents and Chinese Han adolescents at sea level were higher than Chinese Han adolescents born and raised at high altitudes. For both boys and girls, the VO_2max scores of Chinese Tibetan adolescents exceeded Chinese Han adolescents at sea level after the age of 16 years old. Regression analysis showed that altitude was inversely associated with VO_2max. The pace of lung growth may distinguish Chinese Tibetan adolescents from Chinese Han adolescents born and raised at high altitudes. The results of the study suggest that we should focus on the changes in CRF in adolescents at different altitudes and should adopt different CRF interventions for adolescents at different altitudes.

Florentine Normative Values for Physical Fitness in Adolescents Aged 14-15 Years

Physical fitness during youth is linked to the health of today's young people and future adults. Therefore, fitness evaluation can direct any physical exercise interventions and verify improvements. The study aims to provide normative values of the physical fitness of the Florentine adolescent population. This cross-sectional study enrolled 1915 subjects aged 14 and 15 from the first and second high school classes. Tests were performed to assess cardiovascular endurance, upper and lower limb strength, running speed and agility, and lower limb muscle flexibility. Sex and age-related percentiles were elaborated. The study included 1028 subjects in the first class (aged 14.3 ± 0.8 years; 54.5% females) and 887 in the second class (aged 15.3 ± 0.7 years; 53.4% females). Males showed higher values than females except for flexibility. Furthermore, both genders show increased results in transitioning from the first to the second class, except for muscle flexibility and running speed. The percentiles of the present study provide normative values of the physical fitness of the 14-15-year-old Florentine adolescent population. These results, characterized by a sociocultural specificity linked to the territory from which they were collected, can contribute to the assessment and improvement of the physical status of young people, promoting current and future health.

Association between physical activity, sedentary time, and physical fitness of female college students in China

BACKGROUND

Prior research has highlighted the importance of Physical Activity (PA), Sedentary Time (ST), and Physical Fitness (PF) for health. However, there is limited research on the association between PA, ST, and PF in the context of female college students, particularly in Eastern cultures. Therefore, the purpose of this study was to investigate the association between PA, ST, and PF among Eastern female college students to inform policy and practice.

METHODS

The study was conducted from February to May 2022 at East China Normal University, Shanghai, China. A total of 512 Chinese female college students participated in this study through snowball sampling. Participants' PA and ST were investigated using the International PA Questionnaire, and PF was measured using the Chinese National Student Physical Fitness Test. Independent samples t-test and binary logistic regression were used to compare the differences in PF between Active Participants (AP) and Inactive Participants (IP), as well as between Low Sedentary Participants (LSP) and High Sedentary Participants (HSP). Multinomial logistic regression was used to compare the differences in PF between Active and Low Sedentary Participants (ALSP), Active and High Sedentary Participants (AHSP), Inactive and Low Sedentary Participants (ILSP), and Inactive and High Sedentary Participants (IHSP). Data analysis was performed using Statistical Package for the Social Sciences version 28. The level of significance was set at 0.05.

RESULTS

AP showed significantly higher cardiorespiratory fitness (p < 0.05) and overall fitness (p < 0.01) than IP. Compared to IP, AP was less likely to be classified as unfit in terms of cardiorespiratory fitness [Odds Ratio (OR), 0.57; 95% Confidence Interval (CI), 0.38-0.85; p < 0.05]. Compared to IHSP, ALSP (OR, 0.44; 95% CI 0.25-0.76; p < 0.01) and AHSP (OR, 0.54; 95% CI 0.32-0.93; p < 0.05) were less likely to be classified as unfit in terms of cardiorespiratory fitness. Furthermore, compared to IHSP, AHSP (OR, 1.66; 95% CI 1.02-2.70; p < 0.05) and ILSP (OR, 2.09; 95% CI 1.16-3.77; p < 0.05) were more likely to be classified as unfit in terms of their flexibility.

CONCLUSION

There was a positive association between PA, cardiorespiratory fitness, and overall fitness. There was also an association between cardiorespiratory fitness, flexibility, and the combination of PA and ST. These findings suggest that both PA and ST can influence different PF items. Therefore, we recommend that public health policy and practice for college female students should consider PF items when selecting different PA and ST intervention strategies.

Associations of cardiorespiratory fitness, screen time and mental health among Chinese school children

To assess the independent and joint associations between cardiorespiratory fitness (CRF), screen time and mental health among Chinese school-aged children, a cross-sectional study was conducted in 3 primary schools in Wuhan city, China. Children self-reported ST, and their height, weight and CRF were measured. Mental health (anxiety, depressive symptom, and self-esteem) was assessed by self-administered questionnaires. A total of 805 children aged 9.1 ± 0.6 years participated in this study. High ST was associated with significantly increased risk for anxiety and low self-esteem, while high CRF was associated with a decreased risk of low self-esteem. In the joint model, children with low ST and high CRF showed the lowest risk for anxiety (OR: 0.42, 95%CI: 0.20-0.89) and low self-esteem (OR:0.44, 95%CI: 0.24-0.82). High ST and low CRF were negatively associated with mental health in Chinese schoolchildren. Health care and interventions on limiting ST and improving CRF level are warranted to promote the mental health in this population.

Correlates of the Physical Activity Decline during Childhood

PURPOSE

This study aimed to describe longitudinal trends in children's moderate-to-vigorous physical activity (MVPA) and to investigate associations with individual, familial, and school characteristics.

METHODS

A sample of 341 Portuguese children age 5-10 yr (173 girls) from six age cohorts was followed over 3 yr using a mixed-longitudinal design. Physical activity, body mass index (BMI), gross motor coordination, and musculoskeletal fitness were assessed annually. Information on socioeconomic status and school characteristics was collected and analyzed with mixed models.

RESULTS

MVPA shows a similar declining trend in both sexes, but on average, boys exceeded the World Health Organization recommendations of 60 min·d -1 . The best model showed that boys spend, on average, more time in MVPA than girls. Children with lower BMI are less prone to the decline in MVPA, whereas higher levels of musculoskeletal fitness were associated with lower declines in MVPA. Of all school characteristics, only playground dimension was related to MVPA decreasing trajectories.

CONCLUSIONS

MVPA systematically declines from 5 to 10 yr of age in both boys and girls, but boys remained more active than girls across the age range. The best predictors of MVPA decline are sex, BMI, musculoskeletal fitness, and school playground dimension.

Potential Relevance of a Motor Skill “Proficiency Barrier” on Health-Related Fitness in Youth

This study investigated the potential impact of a motor skill proficiency barrier on measures of cardiorespiratory (CRF) and musculoskeletal (MSF) fitness in youth. A sample of 241 youth (114 girls) aged 10 - 18 years, completed the Motor Competence Assessment battery with composite scores indexed according to age- and gender-adjusted percentile scores. Motor competence (MC) levels were categorized as low (≤ 25%tile - proficiency barrier), moderate (≥ 26%tile to < 75%tile), and high (≥ 75%tile). CRF levels (Health Risk, Needs Improvement, and Healthy) were assessed using the Fitnessgram® 20 m PACER test. Low (≤ 20%tile), moderate (≥ 21%tile to ≤ 80%tile), and high (≥ 80%tile) MSF levels were assessed using grip strength normative data. Two 3 × 3 chi-square tests were conducted to determine the probability of MC level predicting CRF and MSF levels. Results demonstrated statistically significant models for performance on both the PACER (χ2[4, N = 241] = 22.65, p < .001) and grip strength (χ2[4, N = 241] = 23.95, p < .001). Strong evidence of a proficiency barrier impacting CRF was noted, as no low skilled youth met the "Healthy" fitness zone standards for PACER performance. Evidence supporting a barrier with grip strength was not as strong, as 20.8% of youth exhibiting low MC displayed high grip strength. However, all individuals with high levels of MC demonstrated at least moderate grip strength. Results emphasize the importance of developing MC during childhood as it may provide a protective effect against unhealthy CRF and MSF across youth.HighlightsThese data support the notion of Seefeldt's (1980) proficiency barrier as it relates to CRF, as no youth demonstrating low MC met the healthy fitness zone criteria for PACER performance. The development of MC may both directly and indirectly provide a protective effect against unhealthy CRF levels across childhood and adolescence.Evidence supporting a proficiency barrier with MSF as measured by grip strength was not as strong; however, all individuals with high levels of MC demonstrated at least moderate grip strength. Thus, the development of MC may be a protective factor to mitigate low levels of MSF via enhanced neuromuscular function.Promoting the development of MC in a variety of developmentally appropriate activities and settings (e.g. MC skills practice, structured and unstructured play, and performance contexts) is important to promote positive trajectories of CRF and MSF across childhood and adolescence.

Health-Related Physical Fitness in Adolescents from Spain, Estonia and Iceland: A Cross-Sectional, Quantitative Study

The benefits of physical fitness (PF) for health are well-known. Low PF significantly contributes to the prevalence of obesity in adolescents, with an increased risk of developing chronic diseases. The objectives of the present study were to explore the health-related PF components and body composition levels in adolescents in three European cities, and their differences. The present study is a cross-sectional, descriptive, and quantitative research effort with 1717 participants aged between 13−16 years (48% girls), enrolled in public and private secondary schools in Seville (Spain), Reykjavik (Iceland) and Tartu (Estonia). The ALPHA fitness battery test was used with the following tests: handgrip strength, standing broad jump, 4 × 10 m speed-agility, 20 m shuttle run, and anthropometric variables. Regarding body composition, differences were detected for city and gender in height (p < 0.001), weight (p < 0.001), body fat percentage (p < 0.001), and waist circumference (p < 0.001); but no differences were reported for BMI for both city (p = 0.150) and gender (p = 0.738). Similarly, concerning PF, it was detected statistically significant differences between cities and gender in handgrip strength (p < 0.001), jump test (p < 0.001), speed-agility test (p < 0.001), and cardiovascular endurance in both variables (p < 0.001). In total, 26.8% of the boys and 27.3% of the girls were categorized as overweight; 18.1% of the boys and 31.2% of the girls had an excessive percentage of fat mass; and 22.7% of the boys and 22.2% of the girls showed an excessive waist circumference. The participants from Seville presented the lowest results in PF tests. In contrast, Reykjavik, with the highest results in the endurance and speed-agility tests, and Tartu, with higher results in the manual grip strength and long jump tests, shared the highest results.

Age- and Sex-Specific Physical Fitness Reference and Association with Body Mass Index in Hong Kong Chinese Schoolchildren

There is lacking a population-based study on the fitness level of Hong Kong schoolchildren, and it seems that increasing childhood obesity prevalence has shifted the classification of healthy fitness, with 'underfit' as normal. This cross-sectional territory study aimed to develop an age- and sex-specific physical fitness reference using a representative sample of children aged 6-17 and to determine the associations with body mass index in schoolchildren. The study analyzed Hong Kong School Physical Fitness Award Scheme data covering grade 1 to grade 12 students' physical fitness and anthropometric measurements from 2017 to 2018. This reference was established without the impact due to COVID-19. Four aspects of physical fitness tests were measured using a standardized protocol, including (i) upper limb muscle strength, (ii) one-minute sit-up, (iii) sit-and-reach, and (iv) endurance run tests. The generalized additive model for location, scale, and shape was used to construct the reference charts. A Mann-Whitney U test was used to compare the mean differences in age, weight, and height, and a Pearson's chi-square test was used to examine the distributions of sex groups. A Kruskal-Wallis test was used to compare the group differences in BMI status, followed by the Dunn test for pairwise comparisons. A 5% level of significance was regarded as statistically significant. Data of 119,693 students before the COVID-19 pandemic were included in the analysis. The association between physical fitness level and BMI status varied depending on the test used, and there were significant differences in fitness test scores among BMI groups. The mean test scores of the obese group were lower in most of the tests for both boys and girls, except for handgrip strength. The underweight group outperformed the obese group in push-ups, one-minute sit-ups, and endurance run tests, but not in handgrip strength. In conclusion, a sex- and age-specific physical fitness reference value for Hong Kong Chinese children aged 6 to 17 years old is established, and this study demonstrated a nonlinear relationship between BMI status and physical fitness. The reference will help to identify children with poor physical fitness to offer support and guidance on exercise training. It also serves as a baseline for assessing the impact of the COVID-19 pandemic on Hong Kong students' physical fitness.

Recreational Soccer Training Effects on Pediatric Populations Physical Fitness and Health: A Systematic Review

This systematic review analyzed the effects of recreational soccer programs on physical fitness and health-related outcomes in youth populations. Studies were sought in the following databases: (i) PubMed, (ii) Scopus, (iii) SPORTDiscus, and (iv) Web of Science. The eligibility criteria included (1) population: youth (<18 years old) populations with no restrictions on sex or health condition; (2) intervention: exposure to a recreational soccer training program of at least four weeks duration; (3) comparator: a passive or active control group not exposed to a recreational soccer training program; (4) outcomes: physical fitness (e.g., aerobic, strength, speed, and change-of-direction) or health-related measures (e.g., body composition, blood pressure, heart rate variability, and biomarkers); (5) study design: a randomized parallel group design. The search was conducted on 6 September 2022 with no restrictions as to date or language. The risk of bias was assessed using the PEDro scale for randomized controlled studies. From a pool of 37,235 potentially relevant articles, 17 were eligible for inclusion in this review. Most of the experimental studies revealed the beneficial effects of recreational soccer for improving aerobic fitness and its benefits in terms of blood pressure and heart-rate markers. However, body composition was not significantly improved by recreational soccer. The main results revealed that recreational soccer training programs that are implemented twice a week could improve the generality of physical fitness parameters and beneficially impact cardiovascular health and biomarkers. Thus, recreational soccer meets the conditions for being included in the physical education curriculum as a good strategy for the benefit of the general health of children and young people.

Duration of Daytime Napping Is Related to Physical Fitness among Chinese University Students

Reportedly, daytime napping affects the physical fitness of athletes. However, results of these studies are conflicting, and may not be generalizable to all populations. Early adulthood is an important period linking adolescents and adults, during which building good physical fitness is crucial for their remaining lives. Thus, we investigated whether daytime napping duration is associated with physical fitness among Chinese university students. This study was based on an annual physical health examination for all university students and included 11,199 participants (6690 males; 4509 females). The daytime napping duration was assessed using a self-report questionnaire. Physical fitness was measured with a 50 m sprint; 1000 m (for males) and 800 m (for females) runs; standing long jump, sit-and-reach, pull-up (for males), and sit-up (for females) tests; and vital capacity. The adjusted association was evaluated using analysis of covariance. Of the participants, 86% napped regularly. After covariate adjustment was performed, significant V-shaped associations were observed between the daytime napping duration and the 50 m sprint and 800 m run results in males and females. Inverted V-shaped associations were observed between the daytime napping duration and the sit-and-reach, standing long jump, and pull-up test performances and vital capacity in males and between the daytime napping duration and the standing long jump test performance in females. Daytime napping for <30 min may have beneficial effects on physical fitness among university students.