Physical activity, cardiorespiratory fitness, and obesity among Chinese children

International fitness scale (IFIS): association with motor performance in children with obesity

Background

Overweight and obesity are defined as abnormal or excessive fat accumulation that presents a risk to health; and compared with their normal-weight peers, these individuals tend to have a lower level of self-confidence, and consequently lower physical activity adherence. Due to these self-perceived barriers, the aim of our study was to evaluate the efficacy of an online training program on self-reported physical fitness (SRPF) in children with obesity (OB).

Methods

A total of 32 children with OB carried out physical fitness (PF) tests and were asked to complete the International Fitness Enjoyment Scale (IFIS) questionnaire. The physical fitness tests were the Standing Broad Jump (SBJ), the 6-Min Walking Test (6MWT) and the 4 × 10 m sprint test. Children participated in a 3-weekly 60-min training session through Zoom platform. Before the beginning of the training protocol, OB children were compared with normal weight (NW) ones for PF batteries and the IFIS questionnaire. Changes in performances after the training were assessed by paired Student t and Wilcoxon tests.

Results

After the online training program children increased their performance in 6MWT (mean difference (MD) = 54.93; p < 0.0001) in SBJ (MD = 10.00; p = 0.0001) and in 4 × 10 m sprint test (MD = -0.78; p < 0.0001). No differences were found in children's physical fitness perception.

Discussion

Our study highlighted how a structured online training program can lead to improvements in PF of children with OB. Instead, the lack of differences in SRPF after the training suggests interesting questions to be explored on the aspects linked to self-perception. Therefore, even if our training protocol could not directly improve SRPF in children with obesity, the enhancement of their PF could be a starting point for achieving this result with a longer training period and consequently improve PA participation for children with OB.

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.

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.

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.

Association between nutritional status, physical fitness and executive functions in preadolescents: A person-centered approach

Objective

In the current study, a person-centered approach was adopted to investigate the relationship between nutritional status and physical fitness profiles and executive functions (EF) in preadolescents.

Methods

Participants (M age = 10.8 years; Male = 50.8%) were recruited from two primary schools in Hong Kong. Nutritional status [body mass index (BMI)], physical fitness including cardiorespiratory fitness (CRF, predicted VO2max, multi-stage fitness test) and speed-agility (20-m sprint) were measured on school days. EF performance was measured using the Flanker task (inhibition) and the Sternberg task (working memory).

Results

Data from 120 preadolescents were considered valid. Three distinct profiles were identified by a person-centered approach. Profile 1 was featured by high BMI (21.61 ± 3.38 kg/m2), poor VO2max (33.29 ± 23.96 ml/kg/min), and slow 20-m sprint (4.51 ± 0.13 s). Profile 2 was featured by low BMI (15.99 ± 3.38), fair VO2max (44.98 ± 23.96) and fast 20-m sprint (3.97 ± 0.13). Profile 3 was featured by low BMI (15.63 ± 3.38), poor VO2max (32.37 ± 23.96), and slow 20-m sprint (4.48 ± 0.13). Wald chi-square test revealed preadolescents in profile 1 and profile 2 performed better than profile 3 in accuracy of Flanker task (1 vs. 3: χ 2 = 12.23, P < 0.001; 2 vs. 3: χ 2 = 10.86, P = 0.001). That is, for normal weight preadolescents with poor CRF and speed-agility, those with superior nutritional status performed better in inhibition. For normal weight preadolescents with poor nutritional status, those with superior CRF and speed-agility had better inhibitory capacity.

Conclusion

Compared to the commonly used variable-centered approach, this person-centered approach is a valuable addition that expands the understanding of the association between nutritional status, physical fitness and EF in preadolescents. Results are discussed with regards to maximizing health behaviors and implications for educational policy.

Lower fitness levels, higher fat-to-lean mass ratios, and lower cardiorespiratory endurance are more likely to affect the body mass index of Saudi children and adolescents

Background

Several studies suggest that health-related physical fitness may play a prominent role in preventing obesity in children and adolescents.

Objectives

The present study examined fitness levels using five components of health-related fitness in Saudi students aged 10-17 years (fat-to-lean mass ratio, cardiorespiratory endurance, upper body strength and endurance, abdominal muscle strength and endurance, and flexibility). Subsequently, the association between BMI and a health-related fitness index (HR-PFI) based on the five fitness components was investigated.

Methods

The study was conducted on 1,291 students with a mean age of 12.95 ± 1.72 years. Participants included 1,030 boys aged 12.80 ± 1.79 years, with 479 young boys (11.24 ± 0.81b years), and 551 adolescents (14.16 ± 1.21 years). Moreover, the study examined 261 girls averaging 13.54 ± 1.2 years old, with 66 young girls (11.92 ± 0.27 years), and 195 teenage girls (14.09 ± 0.85 years). Each participant's health-related fitness level was assessed by the following tests: Bioelectrical Impedance Analyzer (BIA) for body composition, one-mile run/walk test for cardiorespiratory endurance, curl-up test for abdominal muscle strength and endurance (AMSE), push-up test for upper body strength and endurance (UBSE), and back-saver sit-and-reach test for flexibility.

Results

The overall prevalence of overweight and obesity was 10.4 and 24.7% in boys and 10 and 8.4% in girls, respectively. The mean Z-scores of performances decreased from the underweight to the obese groups. BMI was positively associated with the ratio of fat mass to lean mass and negatively associated with cardiorespiratory endurance in the overall group of participants as well as in the subgroups by sex and age categories. BMI was also negatively associated with flexibility and HR-PFI in the total group, UBSE, AMSE, and HR-PFI in prepubertal boys, and UBSE in prepubertal girls. The coefficient of determination values was 0.65 in the total group, 0.72 in prepubertal boys, 0.863 in adolescent boys, 0.956 in prepubertal girls, and 0.818 in adolescent girls.

Conclusions

Overall health-related physical fitness, fat-to-lean mass ratio, and cardiorespiratory endurance are the factors that most affect BMI in Saudi students aged 10 to 17.

Effects of a SMART Goal Setting and 12-Week Core Strength Training Intervention on Physical Fitness and Exercise Attitudes in Adolescents: A Randomized Controlled Trial

This study aimed to analyze the impacts of a 12-week core strength training (CST) and goal-setting (GS) program on the core endurance, agility, sprinting, jumping, grip strength, and exercise attitude in a group of adolescents. This study followed a randomized parallel design in which 362 adolescents (age: 14.5 ± 1.07 years; body mass index: 19.82 ± 3.64) were allocated to a GS (n = 89), CST (n = 92), or GS + CST (n = 90) program or to a control group (n = 91). Participants were assessed two times (baseline and postintervention) for the following tests: (i) 50 m dash, (ii) grip strength, (iii) long jump, (iv) 1000 m running for boys and 800 m for girls, (v) core endurance, and (vi) exercise attitude. Significant differences (p < 0.05, η2p = 0.035−0.218) were found between the four groups of the six components of physical fitness and the three components of attitude toward exercise (target attitudes, behavioral habits, and sense of behavioral control). Between-group analysis revealed that the GS + CST had significant advantages (p < 0.05) over the CON in terms of the 50 m dash (Cohen’s d = 0.06), grip strength (Cohen’s d = 0.19_left, 0.31_right), 800/1000 m running (Cohen’s d = 0.41), core endurance (Cohen’s d = 0.95), and sense of behavioral control (Cohen’s d = 0.35). Between-group analysis also revealed that the CST had significant advantages over the CON in terms of grip strength (Cohen’s d = 0.27_left, 0.39_right), 50 m (Cohen’s d = 0.04), long jump (Cohen’s d = 0.21), 800/1000 m (Cohen’s d = 0.09), and core stability (Cohen’s d = 0.63), which were significantly different from CON (p < 0.05). GS differed from CON only on 50 m (Cohen’s d = 0.02) and core stability (Cohen’s d = 0.13) with a small effect (p < 0.05). We conclude that the combined intervention of GS and CST is more effective in promoting fitness in adolescents, i.e., GS + CST > CST and GS + CST > GS.

Moderating Role of Physical Fitness in the Association Between TV Time and Adiposity Parameters in Adolescents

PURPOSE

To identify whether physical fitness (PF) components play a moderating role in the relationship between TV time and adiposity levels.

DESIGN

Cross-sectional study.

SETTING

Few studies have examined if different PF levels modify the association between TV time and adiposity in adolescents. Studies often focus on the isolated relationships between obesity and TV time, or obesity and PF levels.

SUBJECTS

1071 adolescents (617 girls), aged 12 to 17 years.

MEASURES

Cardiorespiratory fitness (CRF), abdominal muscular endurance, and lower limb strength were evaluated using the protocols of the Projeto Esporte Brasil fitness testing battery. TV time was obtained using a self-reported questionnaire. Body mass index (BMI) and waist circumference (WC) were also assessed. Moderation analyses were conducted through multiple linear regression models with the following associations tested in different models: PF components, TV time, and interaction (PF component x TV time) with adiposity parameters (BMI and WC).

RESULTS

A significant interaction term was found for CRF and TV time in the association with both WC (β: -.005; 95% CI: -.009; -.001; P = .012) and BMI (β: -.002; 95% CI: -.004; -.001; P = .009).

CONCLUSION

CRF moderates the relationship between TV time and adiposity measures in this cross-sectional analysis. These data support strategies looking at increasing physical activity levels to improve CRF and avoid the development of excess abdominal obesity and excess weight.

Associations between cardiorespiratory fitness, fatness, hemodynamic characteristics, and sedentary behaviour in primary school-aged children

BACKGROUND

Low cardiorespiratory fitness (CRF) is associated with the development of cardiovascular diseases during childhood, adolescence and older ages. The purpose of the study was to investigate associations between fatness, hemodynamic characteristics and secondary time with CRF in primary school-aged children.

METHODS

Height, weight, body mass index (BMI), blood pressure (BP), heart rate (HR), CRF (20 m shuttle-run) and sedentary time were measured for 105 children (categorized as normal, overweight, obese). The independent sample t-test checked for differences and one-way ANOVA-Post Hoc Test and stepwise linear regression analysis assessed the 20 m shuttle-run performance predictors.

RESULTS

There was a statistically significant difference in CRF between boys and girls. There was a statistically significant difference between (p < 0.05) CRF for Normal weight (M = 47.58 ± 3.26 kg m^-2) and Obese (M = 44.78 ± 3.23 kg m^-2). CRF correlated with age, BMI and sedentary time (r > 0.3; p < 0.05). BMI is the best independent predictor of CRF.

CONCLUSIONS

Children with normal BMI tend to present better CRF performance than obese and overweight children. Sedentary behaviour is associated with lower CRF in primary school-aged children.

Differences in Cardiopulmonary Fitness Between Boy and Girls With Repaired Tetralogy of Fallot

OBJECTIVE

Many studies have demonstrated that patients with repaired tetralogy of Fallot (rTOF) have generally poorer cardiopulmonary fitness (CPF). However, little is known about how the disease results in different CPF in each sex. Therefore, this study aimed to investigate whether sex (and gender) differences affect CPF in children and adolescents with rTOF.

METHODS

This retrospective study recruited adolescents and children (aged 10-18) with rTOF following an acute stage of tetralogy of Fallot (TOF) who received cardiopulmonary exercise testing (CPET) in the past 10 years. CPF was determined by symptom-limited CPET with a treadmill under ramped Bruce protocol. Boys and girls were categorized into groups based on body mass index (BMI) and fat mass index (FMI). The BMI was grouped by Taiwanese obesity cutoff points. The FMI was categorized by the body fat percentage. Excess adiposity was defined as (1) "overweight" and "obese" by BMI and (2) greater than the sex- and age-specific 75th percentile of whole subjects by FMI.

RESULTS

A total of 185 participants (104 boys and 81 girls) with rTOF were recruited for the final analysis. Within the BMI category, 76 boys and 63 girls were in the normal group, whereas 28 boys and 18 girls were in the excessive adiposity group. Within the FMI category, 77 boys and 60 girls were in the normal group, whereas 27 boys and 21 girls were in the excessive adiposity group. The analysis of the body composition of rTOF subjects showed that there was no statistically significant difference between the subgroups of the two sexes, but both showed a smaller body size than normal Taiwanese children. When comparing the CPF within different BMI and FMI groups, the children in the excessive adiposity group had significantly lower values in metabolic equivalents (MET) at anaerobic threshold, peak MET, and measured peak oxygen consumption (VO₂) to predicted peak VO₂, regardless of sex. Moreover, boys (60.90%) presented poorer CPF than girls (74.22%, p < 0.001).

CONCLUSION

In Taiwan, patients with rTOF had poorer CPF than healthy peers. This study found that girls with rTOF had better CPF than boys with rTOF. The effect of gender stereotypes on sports participation and self-efficacy might be one of the contributing factors; however, further investigations are warranted to determine the causal effect.

Association between Health-Related Physical Fitness and Respiratory Diseases in Adolescents: An Age- and Gender-Matched Study

The current study examined the differences in health-related physical fitness (HRPF), physical activity (PA), and sedentary behavior (SB) between adolescents with and without ongoing respiratory diseases (RD). This study's participants were from 12 to 15 years old (7th-10th grade) in South Korea. Adolescents with RD were selected through RD-related questions (i.e., asthma, rhinitis, sinusitis, and bronchitis) (n = 139); in contrast, adolescents without RD, randomly selected from the general group, responded to any health problem-related questions as "No" (n = 139). HRPF was measured based on the FITNESSGRAM and EURO FIT test batteries and the measurements of HRPF included cardiovascular endurance, muscular strength, muscular endurance, flexibility, and body composition. All statistical analyses were conducted by SPSS 25.0, and the independent t-test was used to compare the HRPF and PA between the two groups. Moreover, the measured HRPF was compared with a series of analyses of three-way ANOVAs (age × gender × group). Adolescents with RD had a positive association with less participation in PA (p < 0.05; RD: 3081.81 ± 4793.37; general: 2073.64 ± 3123.47) and with more time spent on SB (above 12 h per week: RD group (38.85%) and general group (33.09%)). Furthermore, adolescents in the RD group showed significant effects on all components of HRPF (p < 0.05). Our study confirmed that HRPF is an essential predictor of adolescents' health outcomes, especially for those with RD. We suggest that increased HRPF can be an effective treatment for respiratory diseases in adolescents, and health practitioners should pay more attention to helping adolescents with RD to gain or maintain high HRPF.

Analysis of the Relationship between Obesity Factors and Health-Related Physical Fitness Factors among People with Intellectual Disabilities in South Korea

Little is known about the relationship between health-related physical fitness factors and obesity-related factors in individuals with intellectual disabilities. We investigated the prevalence of obesity and the relationship between obesity-related factors and health-related physical fitness factors among people with intellectual disabilities in South Korea to identify the physical fitness factors that influence the degree of obesity. For obesity-related factors, we measured body composition (height, weight, body mass index—BMI, and body fat percentage) of 108 subjects with intellectual disabilities (mean ± standard deviation; age = 24.4 ± 8.45 years). For health-related physical fitness factors, we measured muscular strength, muscular endurance, and flexibility. There was a significant negative correlation between muscular endurance and obesity factors (BMI, r = −0.306, p < 0.01; body fat percentage, r = −0.402, p < 0.01). Further, the prevalence of obesity (34.3%) and being overweight (17.6%) among people with intellectual disabilities was high in South Korea. In addition, muscular endurance was found to have a significant effect on the obesity level (β = −0.239, p < 0.000). This suggests that a program that considers muscular endurance should be prioritized when implementing an exercise intervention strategy for the treatment of overweight and obesity among people with intellectual disabilities.

Comparison of Peak Oxygen Consumption During Exercise Testing Between Sexes Among Children and Adolescents in Taiwan

Objective: Studies among Western children have observed that the peak oxygen consumption (peak V ˙ O₂) of boys is higher than that of girls, and this difference increases as children progress through adolescence. However, the maturation process and social expectation toward Eastern boys and girls are much different from their Western counterparts. This study aimed to provide baseline information on cardiopulmonary fitness (CRF) of Taiwanese children and adolescents in relation to age and sex. We also evaluated the correlation between body mass and CRF and compared the CRF between non-obese and overweight/obese children. Methods: We conducted a retrospective study of children and adolescents aged 4-18 years in Taiwan. Participants were classified into four groups based on age (group 1, aged 4-6; group 2, aged 7-9; group 3, aged 10-13; and group 4, aged 14-18 years). All participants completed symptom-limited exercise test by treadmill and anthropometric measurements through bioelectrical impedance method. Results: In total, 897 (448 men, 449 women) participants were analyzed. Boys had higher peak V ˙ O₂ (all p < 0.01) and peak metabolic equivalent (MET, all p < 0.05) than girls in all the four groups. Age significantly (P < 0.001) correlated with peak V ˙ O₂ in all participants, boys, and girls, with coefficients of determination (R ²) of 0.9349, 0.9433, and 0.9085, respectively. The peak V ˙ O₂ (all p < 0.001) of all the groups and peak MET (all p < 0.05) of group 2-4 associated with BMI and FMI modestly to moderately. Non-obese children had higher peak MET in group 1 (p = 0.049) and group 2-4 (all p < 0.001) than overweight/obese children significantly. Conclusions: The difference in peak V ˙ O₂ and anthropometry-body composition between sexes was observed earlier in children in Taiwan than those in Western countries. Non-obese children had better CRF than overweight/obese children and the difference presented since preschool age.

[Assessment of the nutritional status and physical condition of basic education students in Chile]

Introduction

Introduction: currently, regular physical exercise is the best tool available to promote people's well-being and improve their health. Objective: the objective of the study was to determine the level of physical condition and nutritional status, as well as the relationship between them, in elementary school students in the city of Chillán. Methods: the study is of the descriptive, cross-sectional, relational type. A total of 2500 students participated. To evaluate physical condition, the followingtests were used: Wells and Dillons (flexibility), Sargent Test (lower limb power), AAPHARD's 1-Mile Test (cardiorespiratory resistance), and Sit-ups in 30 seconds (localized muscular resistance). Results: when comparing by sex, men presented significant statistical differences in the physical variables of aerobic capacity (p = 0.00), sit-ups (p = 0.00) and jumping (p = 0.00); only in the case of flexibility did women present better results (p = 0.01). When relating BMI to physical capacity a negative relationship is observed in both sexes-that is, the higher the BMI, the lower the amount of sit-ups (r = -0.032; r = -0.084, women and men, respectively) and aerobic capacity (r = -0.063 and r = -0.023, women and men, respectively). In flexibility and jump a positive though negligible correlation was observed. Conclusion: normal-weight men and women have a better physical condition as compared to those with overweight or obesity. As for sex, men have a better physical condition except for the flexibility test, where women obtain the best results. In addition, a negative relationship is observed in both sexes between physical condition and body composition, where a high BMI results in a low level of physical performance.

The reciprocal relationship between body mass index categories and physical fitness: A 4-year prospective cohort study of 20 000 Chinese children

INTRODUCTION

Body mass index (BMI) categories and physical fitness are associated but the reciprocal relationship between BMI categories and physical fitness has not been investigated. This study aims to investigate the longitudinal reciprocal relationship between BMI categories and physical fitness.

METHODS

This is a population-based 4-year cohort study in 48 elementary schools. Children aged 6 to 9 years at recruitment were included. BMI categories and physical fitness including handgrip strength, core muscle endurance, flexibility, and cardiorespiratory fitness were measured using standard equipment and protocol.

RESULTS

Among 26 392 eligible participants, 19 504 (73.9%) were successfully followed for 3 years. Baseline obesity prevalence was 5.9%. After 3 years, those who were unfit at baseline had an increased risk of obesity (risk ratio [RR] 1.41, 95% CI 1.16-1.71, P < .001) and those who were fit at baseline had a decreased risk of obesity (RR 0.69, 95% CI 0.60-0.80, P < .001) compared with moderately fit children. Furthermore, improvement of fitness predicted decreased risk of obesity. Similarly, normal body weight also predicted better physical fitness. The path analysis confirmed a strong reciprocal relationship between physical fitness and obesity.

CONCLUSIONS

Better physical fitness was prospectively associated with normal weight and vice versa. Physically fit children were more likely to maintain a healthy weight and those with a healthy weight were more likely to be physically fit, which is important for healthy development.

Health profile with body mass index and physical fitness in Swedish adolescents: a cross-sectional study

Objectives Physical inactivity and poor physical fitness in children and adolescents are growing public health problems globally. This study aimed to investigate the correlation between Body Mass Index (BMI) and three physical fitness components, including overall fitness, according to the Swedish Physical power, Mental harmony and Social capacity profile (FMS profile). Another aim was to investigate the test-retest reliability of the FMS questionnaire and fitness tests. Methods A total of 3,692 male and female adolescents in Sweden, between year 2004 and 2013, aged from 16 to 18 years old, were included. Height and weight data were collected to calculate the Body mass index (BMI). The participants performed physical fitness tests, which measure cardio-respiratory fitness, muscular strength and flexibility. The test-retest study included 18 adolescents, aged 16. They answered the FMS questionnaire and participated in the fitness tests with one-week interval. Results A weak inverse relationship between BMI and physical fitness was found: r=-0.06 to -0.07 (p<0.05) for flexibility, r=-0.13 to 0.10 (p<0.001) for strength, r=-0.14 to -0.33 (p<0.001) for cardiorespiratory fitness, and r=-0.15 to -0.27 (p<0.001) for overall fitness. In the test-retest study, the ICC's for strength, flexibility and balance were 0.94, 0.96 and 0.89, respectively. The ICC's for the questions regarding lifestyle ranged from 0.75 to 1.00 and for diet, physical activity and drugs were 0.56, 0.44 and 0.58, respectively. The correlation was stronger in overweight/obese individuals compared to normal weight individuals. Conclusion Overweight and obese individuals scored lower in the fitness tests compared to their normal weight counterparts. The test-retest study revealed that the FMS questionnaire and fitness tests are reliable tools.

Physical Fitness and Bone Health in Young Athletes and Nonathletes

BACKGROUND

Physical activity (PA) and physical fitness (PF) are crucial for bone health. However, children participating in competitive sports with high PA are at a greater risk of fracture from trauma or overuse. Given the importance of bone development during adolescence, associations between commonly used physical fitness tests with distal third radius (R-SoS) and midshaft tibia (T-SoS) speed of sound by quantitative ultrasound were assessed in adolescent athletes and nonathletes.

HYPOTHESIS

The relationship between physical fitness tests and R-SoS and T-SoS will differ depending on sex and athletic status.

STUDY DESIGN

Cross-sectional study.

LEVEL OF EVIDENCE

Level 3.

METHODS

Physical fitness of 285 boys (156 athletes) and 311 girls (74 athletes) aged 10 to 18 years was assessed through strength, speed, agility, and cardiorespiratory tests. Linear regression was used to assess the associations of physical fitness tests with R-SoS and T-SoS.

RESULTS

For boys, favorable associations were observed between physical fitness tests with R-SoS in athletes and T-SoS in both athletes and nonathletes (P < 0.05). For nonathlete girls, favorable associations were found for handgrip (R-SoS and T-SoS, both P < 0.05), whereas the progressive aerobic cardiovascular endurance run, vertical jump, speed at 20 m and 40 m were only favorably associated with T-SoS. For athlete girls, the association between handgrip (P = 0.03), vertical jump, and 4 × 10 m shuttle run (P < 0.05) with T-SoS was significantly related to a bone outcome.

CONCLUSION

The handgrip test and vertical jump were associated with T-SoS in boys and girls independent of sport status. These results suggest that physical fitness is associated with bone health in adolescents, particularly boys, and that the relationship between physical fitness and bone may differ depending on sex and athletic status.

CLINICAL RELEVANCE

Physical fitness tests are simple, easy-to-use tools for monitoring bone health and should be used by sport and health professsionals to promote healthy sport participation and prevent bone injuries.

The dose-response association between V̇O2peak and self-reported physical activity in children

BACKGROUND

Previous research into the association between aerobic fitness and physical activity in children is equivocal. However, previous research has always assumed that such an association was linear. This study sought to characterize the dose-response association between physical activity and aerobic fitness and to assess whether this association is linear or curvilinear and varies by sex, age and weight status.

METHODS

Physical activity (assess using the Physical Activity Questionnaire), aerobic fitness (20 m shuttle-run), BMI, screen-time and socio-demographic data were collected at ages 12, 14 and 16 years in (n = 1422) volunteers from 9 English schools. Multilevel-regression modelling was used to analyse the longitudinal data.

RESULTS

The analysis identified a significant inverted "u-shaped" association between VO₂max and PAQ. This relationship remained having controlling for the influences of sex, age and weight status. Daily screen time >4 hours and deprivation were also associated with being less fit (P < 0.01).

CONCLUSIONS

This longitudinal study suggests that the dose-response relationship between PA and aerobic fitness in children is curvilinear. The health benefits of PA are greater in less active children and that sedentary and less active children should be encouraged to engage in PA rather than more active children to increase existing levels of PA.

Bidirectional associations between fitness and fatness in youth: A longitudinal study

The aim was to examine the bidirectional association between cardiorespiratory fitness (CRF) and fatness in a 2-year longitudinal study conducted in young people. A total of 1082 children (512 females) and 727 adolescents (342 females) with complete data at baseline and follow-up were included. CRF was determined by the 20-m shuttle run test. Height and weight were measured, and body mass index and fat mass index (kg/m² ) were calculated. Triceps and subscapular skinfolds were assessed to compute body fat percentage. Bidirectionality was tested by including CRF and each fatness index as exposures and outcomes, alternatively, in different regression models. CRF was prospectively associated with fatness index levels (ß from -0.186 to -0.528; P < .001), remaining significant in children after adjusting for baseline fatness indices. Fatness indices were prospectively associated with CRF (ß from -0.207 to -0.479; P < .001), with no substantial changes observed in children and female adolescents when baseline CRF was considered. Changes in CRF were prospectively associated with several fatness indices, regardless of body fatness at baseline (ß from -0.062 to -0.220; P < .05). Body fatness changes were associated with future CRF levels, independently of baseline CRF, especially in children of both sexes and male adolescents (ß from -0.079 to -0.260; P < .05). Overall, a bidirectional association was observed between CRF and fatness in children and adolescents. The attainment of optimal CRF and fatness levels in early ages should be promoted since it could result in favorable future fatness and CRF levels, respectively, which are two key determinants of health status.

Análisis de la condición física según sexo, edad, índice de masa corporal y nivel de actividad física en estudiantes de primaria en España

Introducción. La evidencia científica sugiere que la calidad de vida de los escolares se relaciona de forma directa con el estado de su condición física (CF).Objetivo. Analizar la CF según edad, sexo, índice de masa corporal (IMC) y nivel de actividad física en estudiantes de primaria.Materiales y métodos. Se realizó un estudio descriptivo transversal con 103 escolares entre 8 y 12 años de España. La CF se midió mediante la batería ALPHA-Fitness y la actividad física, con el cuestionario Physician-based Assessment and Counseling for Exercise. Los participantes se categorizaron según su nivel de actividad física (no activos versus activos) y su IMC (normo-peso versus sobrepeso-obesidad). Para el análisis se aplicó estadística paramétrica.Resultados. Los varones tuvieron un mejor nivel de CF, pero en ambos sexos se observó un leve incremento de esta a medida que aumentaba la edad. Los escolares con normopeso o activos físicamente tuvieron una mejor capacidad aeróbica y una composición corporal más saludable.Conclusión. Mantener niveles óptimos de CF a lo largo de la vida requiere de la adopción de un estilo de vida saludable desde la infancia, por tanto, es necesario promover la práctica autónoma de actividad física en los escolares.

Weight Status, Physical Fitness, and Health-Related Quality of Life among Chinese Adolescents: A Cross-Sectional Study

PURPOSE

The impact of physical fitness (PF) on adolescents' health-related quality of life (HRQOL) is an important health issue in China. The purpose of this study was to identify whether body mass index (BMI), cardiorespiratory fitness (CRF), and musculoskeletal fitness (MSF) influences HRQOL among Chinese adolescents.

METHOD

The participants were 10,007 students (boys = 5276, 14.14 years ± 1.79; girls = 4829, 14.22 years ± 1.81) who were randomly selected from 30 secondary schools in Shandong, China. BMI, CRF, MSF, and HRQOL were measured and analyzed using ANCOVA and multiple regression.

RESULTS

BMI and physical fitness variables were partially associated with HRQOL in Chinese adolescents. ANCOVA showed a significant difference among BMI categories in terms of physical sense (PS), living convenience, and self-satisfaction (SS) for boys, but this difference was only seen with social activity opportunity (SAO) for girls. Multiple regression found that BMI was significantly associated with SAO. For boys, CRF was associated with the teacher and student relationship and SS, whereas MSF was only associated with PS. For girls, CRF was significantly linked with the parent and children relationship, learning capacity, and attitudes and self-perception (S-P), while MSF was associated with S-P.

CONCLUSION

Enforcing physical activity and enhancing PF will be a crucial pathway in improving adolescents' HRQOL in China.

Cardiorespiratory Fitness Attenuates the Obesity Risk in Chinese Children Who Have Parents with Overweight/Obesity

OBJECTIVE

To evaluate the impact of parental weight status and offspring cardiorespiratory fitness on the risk of obesity among Chinese children.

STUDY DESIGN

This cross-sectional study was conducted in Wuhan, China from May to June 2010. Children's height, weight, and waist circumference were measured for assessing their total and central obesity. Their cardiorespiratory fitness was determined by the 20-m shuttle-run test. We calculated parental body mass index according to self-reported height and weight, and divided it into normal weight or overweight/obesity. Multivariable logistic regression model was applied to estimate the combined relationships of cardiorespiratory fitness and parental weight status with the risk of obesity of children.

RESULTS

A total of 587 Chinese children (343 boys and 244 girls) aged 9.6 (0.7) years participated in this study. Compared with those who had low cardiorespiratory fitness and at least 1 parent with overweight/obesity, children who had high cardiorespiratory fitness and at least 1 parent with overweight/obesity reported lower risks of total obesity (OR 0.12, 95% CI .05-0.30) and central obesity (OR .09, 95% CI .04-0.20), and children who had high cardiorespiratory fitness and no parent with overweight/obesity were 89% (OR 0.11, 95% CI .05-0.24) less likely to have total obesity and 92% (OR .08, 95% CI .04-0.16) less likely to have central obesity (all P < .001).

CONCLUSIONS

High level of cardiorespiratory fitness among children could attenuate the influence of parental obesity on their offspring's weight status.

Associations of physical activity and fruit and vegetable intake with well-being and depressive symptoms among obese schoolchildren in Wuhan, China: a cross-sectional study

BACKGROUND

The prevalence of childhood obesity is increasing and psychological disorder is a common comorbidity of obesity. We investigated the associations of physical activity (PA) and fruit and vegetable (FV) intake with well-being and depressive symptoms among obese schoolchildren.

METHODS

Participants included 188 obese children aged 9.8 ± 0.7 years living in Wuhan, China. Self-administered questionnaires were used to collect the children's PA and FV intake information. PA was considered to be high if the child participated in sport and/or vigorous free play at least 3 days per week with 60 min per day, while sufficient FV intake was defined as consuming FV 5 times per day. Children's well-being and depressive symptoms were assessed by standard questionnaires. Multiple logistic regression was performed to determine the odds ratios (ORs) and 95% confidence intervals (CIs) of the relationships of PA and FV intake with well-being and depressive symptoms.

RESULTS

High PA and sufficient FV intake were independently associated with significantly decreased risks for depressive symptoms (for PA, OR: 0.39, 95% CI: 0.16-0.92; for FV, OR: 0.21, 95% CI: 0.08-0.55) and poor well-being (for PA, OR: 0.35, 95% CI: 0.16-0.74), respectively. Furthermore, interactive inverse associations were observed between combined high PA and sufficient FV intake with poor well-being and depressive symptoms. Compared to their counterparts, children with high PA and sufficient FV intake had significantly reduced risk for poor well-being (OR: 0.16, 95%CI: 0.05-0.55) and depressive symptoms (OR: 0.12, 95% CI: 0.03-0.48).

CONCLUSIONS

High PA and sufficient FV intake are inversely associated with the risks of poor well-being and depressive symptoms among obese Chinese schoolchildren.

Improving Physical Fitness and Cognitive Functions in Middle School Students: Study Protocol for the Chinese Childhood Health, Activity and Motor Performance Study (Chinese CHAMPS)

Background: Sedentary lifestyles and their associated harmful consequences are public health concerns that impact more than half of the world’s youth population in both developed and developing countries. Methods: The Chinese Childhood Health; Activity and Motor Performance Study (Chinese CHAMPS) was a cluster randomized controlled trial to modify school physical activity policies and the physical education (PE) curriculum; using teacher training and parent engagement to increase opportunities and support students’ physical activity and healthy eating. Using a 2 × 2 factorial design, the study tested the incremental effects of increasing the amount and intensity of physical activity, alongside adding support for healthy eating, on health-related and cognitive function outcomes in Chinese middle school students. Results: The intervention was implemented by PE teachers in 12 middle schools in three Chinese cities, with a targeted enrollment of 650 students from August 2015–June 2016. The assessment of the outcomes involved a test battery of physical fitness and cognitive functioning at both baseline and at the end of the intervention. Process information on implementation was also collected. Discussion: The Chinese CHAMPS is a multi-level intervention that is designed to test the influences of policy and environmental modifications on the physical activity and eating behaviors of middle school students. It also addresses some key weaknesses in school-based physical activity interventions.

Body mass index and motor coordination: Non-linear relationships in children 6-10 years

BACKGROUND

Given the concern for health-related consequences of an elevated body mass index (BMI; obesity), the potential consequences of a low BMI in children are often overlooked. The purpose was to evaluate the relationship between the BMI across its entire spectrum and motor coordination (MC) in children 6-10 years.

METHODS

Height, weight, and MC (Körperkoordinationstest für Kinder, KTK test battery) were measured in 1,912 boys and 1,826 girls of 6-10 years of age. BMI (kg/m² ) was calculated. KTK scores for each of the four tests were also converted to a motor quotient (MQ). One-way ANOVA was used to test differences in the BMI, individual test items, and MQ among boys and girls within age groups. Sex-specific quadratic regressions of individual KTK items and the MQ on the BMI were calculated. Girls and boys were also classified into four weight status groups using International Obesity Task Force criteria: thin, normal, overweight, and obese. Differences in specific test items and MQ between weight status groups were evaluated by age group in each sex.

RESULTS

Thirty-one percent of the sample was overweight or obese, whereas 5% was thin. On average, normal weight children had the highest MQ in both sexes across the age range with few exceptions. Overweight/obese children had a lower MQ than normal weight and thin children. The quadratic regression lines generally presented an inverted parabolic relationship between the BMI and MC and suggested a decrease in MC with an increase in the BMI.

CONCLUSION

In general, BMI shows a curvilinear, inverted parabolic relationship with MC in children 6-10 years.

Tracking of Physical Fitness of Primary School Children in Trier: A 4-Year Longitudinal Study

Objective

The aim of this study is to measure the motor development and tracking of physical fitness (PF) components of primary school children of Trier in Germany.

Methods

Two longitudinal cohorts, of 1768 children (915 f, 853 m) aged 5–11, were measured. In longitudinal cohort 1, a total of 116 female and 137 male participants aged 6.80 ± 0.42 years at baseline were measured four times from grade 1 to grade 4 (response: 40.4%). Participants of longitudinal cohort 2 (166 f, 149 m; 6.70 ± 0.36 years at baseline, response: 42.6%) were examined three times from grade 1 to grade 3 with the German Motor Test 6–18 (DMT 6–18).

Results

Physical fitness increased significantly over time in all test tasks except flexibility. Gender-specific differences were found in 20 m sprint, 6-minute run, balancing backwards, jumping sideways, and stand and reach. 74.4% of PF stability coefficients were moderate (r = 0.30 to 0.60). Stability of PF declined with increased time frames. Tracking was lower in girls than in boys. Flexibility showed the highest stability among PF variables (r > 0.50). BMI showed the overall highest stability coefficient with r > 0.7.

Conclusions

Gender-specific differences of PF were obvious but cannot always be secured statistically in primary school. Tracking was only moderate. Variability in the timing and speed of the adolescent growth spurt and sexual maturation influence stability of PF. Results from longitudinal cohort 2 largely confirm those from longitudinal cohort 1.

Fat Mass Index and Body Mass Index Affect Peak Metabolic Equivalent Negatively during Exercise Test among Children and Adolescents in Taiwan

Peak metabolic equivalent (MET) is the most reliable indicator of cardiorespiratory fitness (CRF). The aim of this study was to examine the association between CRF indicated by peak MET and body mass index (BMI) or fat mass index (FMI) in Taiwanese children and adolescents (C-A). Data of 638 C-A aged 10–18 that received symptom-limited treadmill exercise testing was analyzed. Anthropometry-body composition was measured by vector bioelectrical impedance analysis. BMI was defined as body weight (kg)/body height (m)² and FMI was defined as fat mass (kg)/body height (m)². BMI was grouped by Taiwanese obesity cut-off points. FMI Class-I was categorized by percentage of body fat. FMI Class-II used the reference values from Korean C-A. Excess adiposity was defined as (1) “overweight” and “obesity” by BMI, (2) greater than the sex- and age-specific 75th percentile of whole subjects by FMI Class-I, and (3) greater than 95th percentiles of reference value by FMI Class-II. Boys had significantly higher fat mass and FMI, and had more excess adiposity than girls (all p < 0.05). Both boys and girls with excess adiposity (by any definition) had lower MET at anaerobic threshold (AT MET) and peak MET (all p < 0.001). BMI and FMI were significantly negatively associated with both AT MET and peak MET significantly (all p < 0.001). FMI (95% CI: −0.411~−0.548) correlated with peak MET more than BMI (95% CI: −0.134~ −0.372) did. Excess adiposity affected CRF negatively. It is concluded that weight management should start early in childhood.

Health-related physical fitness and physical activity in elementary school students

BACKGROUND

This study examined associations between students' physical fitness and physical activity (PA), as well as what specific physical fitness components were more significant correlates to being physically active in different settings for boys and girls.

METHODS

A total of 265 fifth-grade students with an average age of 11 voluntarily participated in this study. The students' physical fitness was assessed using four FitnessGram tests, including Progressive Aerobic Cardiovascular Endurance Run (PACER), curl-up, push-up, and trunk lift tests. The students' daily PA was assessed in various settings using a daily PA log for 7 days. Data was analyzed with descriptive statistics, univariate analyses, and multiple R-squared liner regression methods.

RESULTS

Performance on the four physical fitness tests was significantly associated with the PA minutes spent in physical education (PE) class and recess for the total sample and for girls, but not for boys. Performance on the four fitness tests was significantly linked to participation in sports/dances outside school and the total weekly PA minutes for the total sample, boys, and girls. Further, boys and girls who were the most physically fit spent significantly more time engaging in sports/dances and had greater total weekly PA than boys and girls who were not physically fit. In addition, the physically fit girls were more physically active in recess than girls who were not physically fit.

CONCLUSIONS

Overall, students' performance on the four physical fitness tests was significantly associated with them being physically active during PE and in recess and engaging in sports/dances, as well as with their total weekly PA minutes, but not with their participation in non-organized physical play outside school.

TRIAL REGISTRATION

ClinicalTrials.gov ID: NCT03015337 , registered date: 1/09/2017, as "retrospectively registered".

Motor Skills of Children and Adolescents With Obesity and Severe Obesity-A CIRCUIT Study

Häcker, A-L, Bigras, J-L, Henderson, M, Barnett, TA, and Mathieu, M-E. Motor skills of children and adolescents with obesity and severe obesity-a CIRCUIT study. J Strength Cond Res 34(12): 3577-3586, 2020-During childhood, excessive weight is negatively associated with the development of motor skills, with overweight children or children with obesity having poorer motor skills compared with children with normal weight. The objectives of the current study are to identify the differences in motor skills between children and adolescents with obesity and severe obesity and the extent of this difference. To do so, we examined cross-sectionally 165 subjects. Physical fitness was analyzed in both subjects with obesity (>97th to 99.9th body mass index [BMI] percentile) and severe obesity (>99.9th BMI percentile) using 8 standardized tests: sit-and-reach, grip force, sit-ups, push-ups, balance, hand-eye coordination, standing long jump and 5-m shuttle run. Poorer performance were observed in subjects with severe obesity in sit-ups (children: 59%; 18.6 ± 17.0 vs. 29.5 ± 23.2 percentile value, p = 0.008), balance (adolescent: 59%; 12.1 ± 12.2 vs. 19.3 ± 13.9 seconds, p = 0.034), and in the 5-m shuttle run (children: 49%; 14.0 ± 13.9 vs. 20.8 ± 19.4 percentile value, p = 0.046; adolescents: 11%; 13.2 ± 2.2 vs. 11.8 ± 1.6 seconds, p = 0.008) compared with obese counterparts. In conclusion, although physical performance was found to be similar between the different obesity levels for most tests, youth with severe obesity demonstrated impairments ranging from 11 to 59% in specific tests.

Motor competence and cardiorespiratory fitness have greater influence on body fatness than physical activity across time

We investigated the longitudinal associations among physical activity (PA), motor competence (MC), cardiorespiratory fitness (VO_2peak ), and body fatness across 7 years, and also analyzed the possible mediation effects of PA, MC, and VO_2peak on the relationships with body fatness. This was a seven-year longitudinal study with three measuring points (mean ages [in years] and respective sample size: 6.75±0.37, n=696; 9.59±1.07, n=617; 13.35±0.34, n=513). PA (moderate-to-vigorous PA-MVPA and vigorous PA-VPA) was monitored using accelerometers. MC was assessed by the "Körperkoordinationstest für Kinder-KTK" test battery. VO_2peak was evaluated using a continuous running protocol until exhaustion. Body fatness was determined by the sum of four skinfolds. Structural equation modeling was performed to evaluate the longitudinal associations among PA, MC, VO_2peak, and body fatness and the potential mediation effects of PA, MC, and VO_2peak . All coefficients presented were standardized (z-scores). MC and VO_2peak directly influenced the development of body fatness, and VO_2peak mediated the associations between MVPA, VPA, MC, and body fatness. MC also mediated the associations between MVPA, VPA, and body fatness. In addition, VO_2peak had the largest total association with body fatness (β=-0.431; P<.05), followed by MC (β=-0.369; P<.05) and VPA (β=-0.112; P<.05). As PA, MC, and VO_2peak exhibited longitudinal association with body fatness, it seems logical that interventions should strive to promote the development of fitness and MC through developmentally appropriate physical activities, as the synergistic interactions of all three variables impacted body fatness.

LIFESTYLE INDICATORS AND CARDIORESPIRATORY FITNESS IN ADOLESCENTS

OBJECTIVE

To evaluate the lifestyle indicators associated with cardiorespiratory fitness in adolescents from Ilhabela, São Paulo, Brazil.

METHODS

The sample consisted of 181 adolescents (53% male) from the Mixed Longitudinal Project on Growth, Development, and Physical Fitness of Ilhabela. Body composition (weight, height, and body mass index, or BMI), school transportation, time spent sitting, physical activity, sports, television time (TV), having a TV in the bedroom, sleep, health perception, diet, and economic status (ES) were analyzed. Cardiorespiratory fitness was estimated by the submaximal progressive protocol performed on a cycle ergometer. Linear regression models were used with the stepwise method.

RESULTS

The sample average age was 14.8 years, and the average cardiorespiratory fitness was 42.2 mL.kg-1.min-1 (42.9 for boys and 41.4 for girls; p=0.341). In the total sample, BMI (unstandardized regression coefficient [B]=-0.03), height (B=-0.01), ES (B=0.10), gender (B=0.12), and age (B=0.03) were significantly associated with cardiorespiratory fitness. In boys, BMI, height, not playing any sports, and age were significantly associated with cardiorespiratory fitness. In girls, BMI, ES, and having a TV in the bedroom were significantly associated with cardiorespiratory fitness.

CONCLUSIONS

Lifestyle indicators influenced the cardiorespiratory fitness; BMI, ES, and age influenced both sexes. Not playing any sports, for boys, and having a TV in the bedroom, for girls, also influenced cardiorespiratory fitness. Public health measures to improve lifestyle indicators can help to increase cardiorespiratory fitness levels.

Do fitness and fatigue affect gait biomechanics in overweight and obese children?

The purpose of this study was to determine how an overweight or obese child's cardiorespiratory fitness level and a state of fatigue affect gait biomechanics.

METHODS

Using a three-dimensional motion analysis system, twenty-nine (female and male) overweight and obese children aged 8-11 years walked on force plates before and after being fatigued from the Progressive Aerobic Cardiovascular Endurance Run (PACER) protocol. Joint moments were calculated for the knee and hip in the frontal and sagittal planes.

RESULTS

In a non-fatigued state, peak hip and knee adductor moments showed a negative relationship with cardiorespiratory fitness level (R²=0.26, 0.26). After the subjects were fatigued, peak hip extensor (p=0.02), peak knee extensor moments (p=0.02) and peak knee adductor moments (p=0.01) showed a significant increase.

CONCLUSION

This trend illustrates that as an overweight or obese individual's fitness improves, the lower limb joint moments in the frontal plane decrease when walking. However, with the introduction of cardiorespiratory fatigue, lower limb joint moments tend to increase in the frontal and sagittal planes. Increased joint stress may have potential implications for obese children performing physical activity, as well as for clinicians who are attempting to intervene in the cycle of obesity.

Relationship between physical activity, physical fitness and multiple metabolic risk in youths from Muzambinho's study

Negative associations between physical activity (PA), physical fitness and multiple metabolic risk factors (MMRF) in youths from populations with low PA are reported. The persistence of this association in moderately-to highly active populations is not, however, well established. The aim of the present study was to investigate this association in a Brazilian city with high frequency of active youths. We assessed 122 subjects (9.9 ± 1.3 years) from Muzambinho city. Body mass index, waist circumference, glycaemia, cholesterolaemia, systolic and diastolic blood pressures were measured. Maximal handgrip strength and one-mile walk/run test were used. Leisure time PA was assessed by interview. Poisson regression was used in the analysis. The model explained 11% of the total variance. Only relative muscular strength and one-mile walk/run were statistically significant (p < .05). Those who needed more time to cover the one-mile walk/run test had an increased in metabolic risk of 11%, and those with greater strength reduced the risk by about 82%. In conclusion, children and youths from an active population who need less time to cover the one-mile walk/run test or who had greater muscular strength showed a reduced metabolic risk. These results suggest that even in children and youths with high leisure time PA, a greater aerobic fitness and strength might help to further reduce their MMRF.

Health factors related to physical activity among children and adolescents: results from Spanish National Health Surveys 2006 and 2011/12

PURPOSE

To describe the prevalence of physical activity during leisure time among children ages 6-14 in 2006 and 2011/12.

DESIGN AND METHODS

A cross-sectional study used individualized data for children 6-14 years of age from the Spanish National Health Surveys in 2006 (n = 5,108 children) and 2011/12 (n = 3,265 children).

RESULTS

Leisure time decreased between 2006 and 2011/12(p < .05). Variables associated with increased physical activity were: normal weight (odds ratio [OR] = 1.87; 95% confidence interval [CI]: 1.37-2.57), children perceived to be in good health by their parents (OR = 2.03;95% CI: 1.43-2.87), and less than 2 hr of screen time per day(OR = 2.00; 95% CI: 1.61-2.47).

PRACTICE IMPLICATIONS

Primary care-based nurses are essential to improving adherence to physical activity.

Vigorous physical activity rather than sedentary behaviour predicts overweight and obesity in pubertal boys: A 2-year follow-up study

Aim: Current physical activity (PA) recommendations indicate that children should get involved in 60 minutes of moderate-to-vigorous PA (MVPA), and should include vigorous-intensity PA at least three days a week. However, it is not known how many minutes of vigorous PA they should do. Using objective methods and a longitudinal design, this study aimed to examine how different PA intensities and sedentary behaviour relate with the risk of being overweight and obese during puberty over a two-year period. Methods: A sample of 136 10–12-year-old (at baseline) boys participated. PA was measured by seven-day accelerometry. Results: From MVPA thresholds, only 90 minutes per day of MVPA had important odds ratios (OR) for being overweight at baseline (OR=8.14, 95% confidence interval [CI] 1.03–64.04). A significant cut-off point for being overweight was indicated by 59 minutes per day of MVPA with at least 14 minutes per day of vigorous PA, and 55 minutes per day MVPA with at least 10 minutes per day of vigorous PA for those who were obese. Sedentary behaviour did not have any significant ORs for being overweight or obese. Subjects who did not meet the thresholds of 5 and 20 minutes per day of vigorous PA at baseline had an increased risk of being overweight (OR=4.05, 95% CI 1.41–11.59, and OR=4.14, 95% CI 1.35–12.73, respectively) and obese (OR=6.54, 95% CI 1.97–21.69, and OR=8.75, 95% CI 1.12–68.51, respectively) two years later. Conclusions: The results indicate that vigorous PA in particular predicts overweight and obesity in boys. They should aim to do at least 60 minutes per day of MVPA. These results contribute to the recommendations suggesting that a minimum of 15 minutes per day of vigorous PA is desired to reduce the risk of developing overweight/obesity in later puberty.

Aptidão cardiorrespiratória, indicadores sociodemográficos e estado nutricional em adolescentes

INTRODUÇÃO: níveis inadequados de aptidão cardiorrespiratória na adolescência estão inversamente associados a fatores de risco cardiovasculares e metabólicos.OBJETIVO: verificar a associação da aptidão cardiorrespiratória com indicadores sociodemográficos e o estado nutricional em adolescentes.MÉTODOS: estudo transversal realizado em 627 adolescentes (361 moças), com idades de 14 a 17 anos, de ambos os sexos em uma cidade de médio/baixo Índice de Desenvolvimento Humano (IDH). Foram coletadas as variáveis antropométricas (massa corporal - MC e estatura - EST) para a obtenção do índice de massa corporal (IMC=MCkg/ESTm2) e as informações sociodemográficas (idade, nível econômico e área de domicílio). Para análise da aptidão cardiorrespiratória baixa (teste correr/caminhar 1.600 metros), considerou-se o tempo de realização do teste igual ou superior a 7:45 minutos (min) e 7:30 min para os rapazes de 14 e de 15 a 17 anos, respectivamente, e o tempo de 10:30 min para as moças.RESULTADOS: a aptidão cardiorrespiratória baixa foi verificada em 35,3% dos rapazes e 35,5% das moças. Os rapazes pertencentes aos estratos econômicos menos favorecidos (Classe C: RP=0,54; IC95%=0,31-0,93; Classe: D+E: RP=0,46; IC95%=0,22-0,98) estiveram menos expostos a baixos níveis de aptidão cardiorrespiratória. Por outro lado, os rapazes que nasceram com baixo peso (RP=1,49; IC95%=1,04-2,13) e os rapazes e as moças residentes na área urbana (rapazes: RP=1,79; IC95%=1,28-2,50; moças: RP=1,32; IC95%=0,99-1,75) apresentaram maiores probabilidades de terem baixa aptidão cardiorrespiratória.CONCLUSÃO: os indicadores que apresentaram associação com a aptidão cardiorrespiratória baixa para os rapazes foram área de domicílio urbana e nível econômico intermediário e baixo. Para as moças, o resultado associou-se somente com a área de domicílio. Sugerem-se intervenções para a promoção da saúde voltadas principalmente para os adolescentes residentes na área urbana e pertencentes aos estratos econômicos mais abastados.

Physical activity, body mass index, and cardiorespiratory fitness among school children in Taiwan: a cross-sectional study

There is evidence that cardiorespiratory fitness and physical activity significantly reduce cardiovascular risks in adults. A better understanding of the association between cardiorespiratory fitness, physical activity, and childhood obesity is vital in assessing the benefits of interventions to prevent obesity. This study was to examine the relationship between physical activity, body mass index, and cardiorespiratory fitness levels in Taiwanese children. A cross-sectional study was designed. Study participants consisted of 2419 school children (1230 males and 1189 females) aged 12 years old living in a southern Taiwan county with one the highest countrywide rates of childhood obesity. The weight status of the participants was defined as underweight, normal, overweight, or obese according to specific criteria. Cardiorespiratory fitness was then assessed by an 800-m run. Participants were queried on their physical activity habits via a questionnaire survey. The overall prevalence of overweight/obesity was 29.6%. Normal, underweight and overweight boys and girls had an increased odds ratio of being categorized with higher cardiorespiratory fitness than obese one for both gender. A significantly higher level of cardiorespiratory fitness was found in children who engaged in regular physical activity than in children who engaged only in irregular physical activity. Obese children are more likely to lack cardiorespiratory fitness. Physically active children have significantly better cardiorespiratory fitness levels than inactive children. This study supports the conclusion that BMI and physical activity are significantly correlated with cardiorespiratory fitness levels. Findings may provide educational professionals with information to assist their developing effective health promotion programs to healthy weight and improving cardiorespiratory fitness for children.

[Association between nutritional status and physical abilities in children aged 6 to 18 years in Medellin (Colombia)]

INTRODUCTION

Nutritional disorders in childhood may cause a decline in motor abilities and increased morbidity and mortality in adulthood.

OBJECTIVE

To assess the association between nutritional status and motor abilities.

MATERIALS AND METHODS

A cross-sectional study was performed that included 12,872 children aged between 6 and 18 years who underwent a clinical evaluation and various physical tests.

RESULTS

Among the children, 66% had a Tanner maturation stage 1 and 2, 6% were under-nourished, and 12.2% were at risk of overweight and obesity. The obese children had a decrease in aerobic power (in 2.72 mL O2 kg(-1)·min(-1); 95%CI: 1.89 to 3.56; P<.001), speed (0.14m·sec; 95%CI: 0.06 to 0.22; P<.001), explosive strength (0.10 m; 95%CI: 0.06 to 0.13; P<.001), agility, strength endurance and balance. Under-nourished children showed a decrease in speed (0.13 m·sec; 95%CI: 0.06 to 0.20; P<.001), explosive strength (0.04 m; 95%CI: 0.01 to 0 07; P<.004), and strength endurance.

CONCLUSIONS

There was an association between nutritional status and motor abilities in the children included in this study. Obese children showed the worst results in physical tests, and the under-nourished ones showed a decrease in speed, explosive strength and strength endurance.

Determinants of metabolic syndrome in Chinese schoolchildren

The objective of this study was to identify the potential risk factors of metabolic syndrome (MetS) among Chinese schoolchildren. A cross-sectional study among 624 children (357 boys and 267 girls, aged 9.6 ± 0.7 years) was conducted in Wuhan, China, from May to June 2010. MetS was defined according to the criteria proposed by De Ferranti and the International Diabetes Federation (IDF) criteria. Data on cardiorespiratory fitness (CRF), household income, parental hypertension, and children's personal information, including birth weight, preterm birth, and breast-feeding, reported by their parents were obtained. Multiple logistic regression showed that CRF (odds ratio [OR] = 0.68; 95% confidence interval [CI] = 0.60-0.77), breast-feeding (OR = 0.32; 95% CI = 0.10-0.97), and paternal hypertension (OR = 5.06; 95% CI = 1.20-21.37) were all independently associated with MetS. In conclusion, low CRF and paternal hypertension significantly increase the risk, whereas breast-feeding may reduce the risk of MetS among Chinese schoolchildren.

Cardiorespiratory fitness and nutritional status of schoolchildren: 30-year evolution

OBJECTIVE

To compare the changes in cardiorespiratory fitness in evaluations performed every ten years since 1978/1980, according to the nutritional status and gender of students in the city of Ilhabela, Brazil.

METHODS

The study is part of the Mixed Longitudinal Project on Growth, Development and Physical Fitness of Ilhabela. The study included 1,291 students of both genders, aged 10 to 11 years old. The study periods were: 1978/1980, 1988/1990, 1998/2000, and 2008/2010. The variables analyzed were: body weight, height, and cardiorespiratory fitness (VO2max - L.min-1 and mL.kg-1.min-1) performed using a submaximal progressive protocol on a cycle ergometer. Individuals were classified as normal weight and overweight according to curves proposed by the World Health Organization of body mass index for age and gender. Analysis of variance (ANOVA) with three factors followed by the Bonferroni method were used to compare the periods.

RESULTS

The number of normal weight individuals (61%) was higher than that of overweight. There was a significant decrease in cardiorespiratory fitness in both genders. Among the schoolchildren with normal weight, there was a decrease of 22% in males and 26% in females. In overweight schoolchildren, males showed a decrease of 12.7% and females, of 18%.

CONCLUSION

During a 30-year analysis with reviews every ten years from 1978/1980, there was a significant decrease in cardiorespiratory fitness in schoolchildren of both genders, which cannot be explained by the nutritional status. The decline in cardiorespiratory fitness was greater in individuals with normal weight than in overweight individuals.

The relationship between physical activity, physical fitness and overweight in adolescents: a systematic review of studies published in or after 2000

Background

Not only in adults but also in children and adolescents, obesity increases the risk for several health disorders. In turn, many factors including genetic variations and environmental influences (e.g. physical activity) increase the risk of obesity. For instance, 25 to 40 percent of people inherit a predisposition for a high body mass index (BMI). The purpose of this systematic review was to summarize current cross-sectional and longitudinal studies on physical activity, fitness and overweight in adolescents and to identify mediator and moderator effects by evaluating the interaction between these three parameters.

Methods

The electronic academic databases PubMed, SportDiscus, WEB OF KNOWLEDGE and Ovid were searched for studies on physical activity, fitness and overweight in adolescents aged 11 to 19 years (cross-sectional studies) and in adolescents up to 23 years old (longitudinal studies) published in English in or after 2000.

Results

Twelve cross-sectional and two longitudinal studies were included. Only four studies analyzed the interaction among physical activity, fitness and overweight in adolescents and reported inconsistent results. All other studies analyzed the relationship between either physical activity and overweight, or between fitness and overweight. Overweight—here including obesity—was inversely related to physical activity. Similarly, all studies reported inverse relations between physical fitness and overweight. Mediator and moderator effects were detected in the interrelationship of BMI, fitness and physical activity. Overall, a distinction of excessive body weight as cause or effect of low levels of physical activity and fitness is lacking.

Conclusions

The small number of studies on the interrelationship of BMI, fitness and physical activity emphasizes the need for longitudinal studies that would reveal 1) the causality between physical activity and overweight / fitness and overweight and 2) the causal interrelationships among overweight, physical activity and fitness. These results must be carefully interpreted given the lack of distinction between self-reported and objective physical activity and that studies analyzing the metabolic syndrome or cardiovascular disease were not considered. The importance of physical activity or fitness in predicting overweight remains unknown.

Physical activity, fitness and the energy cost of activities: implications for obesity in children and adolescents in the tropics

The tropics cover a large section of the world in which both developed and developing countries are situated. Rapid socioeconomic development, modernization, urbanization, and globalization have affected both the food market and physical activity (PA), which in turn have propelled the obesity epidemic in the tropics. There is growing concern that overweight and obesity are emerging as major health problems among children and adolescents in the tropics, despite the fact that undernutrition still exists in many of these countries. Physical inactivity, a low metabolic rate, and lack of physical fitness (PF) have been linked to overweight and obesity. Moreover, PF in several tropical countries is declining, and these changes may be a threat to future health, as low PA and PF levels are important risk factors for noncommunicable chronic diseases. Previous studies have reported that the relationships among PA, PF, overweight, and obesity are inconsistent and inconclusive. There is no indication that variances in the energy cost of physical activities lead to obesity. Despite a lack of definite evidence to prove a causal relationship, there is enough certainty that physical inactivity and low fitness levels are linked to overweight and obesity. Hence, people living in tropical countries need to be encouraged to lead a healthier lifestyle by increasing their PA levels and reducing sedentary behaviors to prevent overweight or obesity.

Association between knee alignment, body mass index and physical fitness variables among students: a cross-sectional study

OBJECTIVE

To assess the association between malalignment of the knees (genu valgum) and variables of physical fitness among schoolchildren.

METHODS

We analyzed data collected between the years 2000 to 2009. The sample comprised 1,141 schoolchildren of both sexes aged 06 to 18 years. To participate in the research, the students must meet the following criteria: age between 6 and 18 years and a full assessment of physical fitness, including measurement of genu valgus in at least one of the semester assessments. Postural evaluation (valgus) was determined by the intermalleolar distance, in centimeter. Body Mass Index (BMI) determined through the growth curves of the World Health Organization. Physical fitness variables (strength of upper and lower limbs, agility, speed and flexibility), were taken according to CELAFISCS standardization.

RESULTS

Among male students it was found a prevalence of 23.2% obese, 44.4% overweight and 32.4% eutrophic. Among females, the values were: 30.9% obese, overweight 39.5% and 20.6% eutrophic. When analyzing the prevalence of valgus according to the BMI classifications it was, found a significant positive association in both sexes. Association was found between genu valgum and upper limbs strength only in crude analysis. The other variables, agility, speed and flexibility were not associated even when the analysis was adjusted.

CONCLUSION

there was a positive association between malalignment of the knees, body mass index and physical fitness among schoolchildren.

Effects of a recreational physical activity and healthy habits orientation program, using an illustrated diary, on the cardiovascular risk profile of overweight and obese schoolchildren: a pilot study in a public school in Brasilia, Federal District, Brazil

INTRODUCTION

Educative strategies need to be adopted to encourage the consumption of healthy foods and to promote physical activity in childhood and adolescence. The effects of recreational physical activity and a health-habit orientation program using an illustrated diary on the cardiovascular risk profile of overweight and obese children was investigated.

METHODS

The weight and height of 314 schoolchildren aged between 9 and 11 years old, in a public school in Brasilia, Federal District, Brazil, were recorded. According to the body mass index (BMI) classification proposed by the World Health Organization, 84 were overweight or obese for their age and sex. Of these children, 34 (40%) participated in the study. Students were divided into two groups matched for sex, age, BMI, percent body fat (%BF): the intervention group (IG, n = 17) and the control group (CG, n = 17). The IG underwent a program of 10 weeks of exercise with recreational activities and health-habit orientation using an illustrated diary of habits, while no such interventions were used with the CG during the study period. Before and after the intervention, the children's weight, height, BMI, %BF, waist circumference (WC), maximum oxygen intake (VO2max), total cholesterol (TC), high density lipoprotein (HDL), low density lipoprotein (LDL), triglycerides, glucose, eating habits, and physical activity level (PAL) were assessed. In analyzing the data, we used descriptive statistics and paired and unpaired t-tests, using a significance level of 0.05. For assessment of dietary habits, a questionnaire, contingency tables, and the chi-squared test were used, with <0.05 set as the significance level.

RESULTS

After 10 weeks of intervention, the IG showed a reduction in BMI (pre: 22.2 ± 2.1 kg/m(2) versus [vs] post: 21.6 ± 2.1 kg/m(2), P < 0.01); WC (pre: 70.1 ± 6.1 cm vs post: 69.1 ± 5.8 cm, P < 0.01); %BF (pre: 29.2% ± 4.6% vs post: 28.0% ± 4.8%, P < 0.01); systolic blood pressure (P < 0.01); VO2max (P = 0.014); TC (P < 0.01); LDL (P < 0.01); triglycerides (P < 0.01); and intake of candy (P < 0.01) and soda drinks (P < 0.01), while an increase in the consumption of fruit (P < 0.01) and PAL (P < 0.01) were observed. The CG did not show any change in the health parameters assessed.

CONCLUSION

The program was effective in reducing risk factors for cardiovascular disease and the use of an illustrative diary may have been the key to this result, since students were motivated to change their poor eating habits and to increase their physical activity level.

Relationship of body fat and cardiorespiratory fitness with cardiovascular risk in Chinese children

Backgrounds/Objectives

Cardiorespiratory fitness (CRF) and body fat play an important role in elevated risk for cardiovascular disease (CVD). However, the combined effects of CRF and obesity on metabolic health in Chinese children are unclear. The purpose of this study was to investigate the independent and combined associations between body fat, CRF, and CVD risk in Chinese schoolchildren.

Methods

The study subjects comprised 676 schoolchildren (392 boys and 284 girls, aged 9.6±0.7 yrs old) in Wuhan, China. Their body mass index (BMI), waist circumference (WC), CRF, blood pressure (BP), lipids, glucose, and pubertal status were assessed. Children were categorized into different groups based on their BMI, WC, and CRF using Chinese obesity cut-off points and CRF sex-specific median points. Metabolic Risk Score (MRS) was computed based on the standardized scores of BP, lipids, and glucose.

Results

Multiple linear regression models showed that, in the separate models, body fat was positively associated with MRS while CRF was inversely associated with MRS (p<0.001). However, when assessed simultaneously, only body fat had a significant association with MRS (p<0.001). In general, low-fit children had a lower MRS compared to their counterparts, and a significant difference between the two extreme groups was observed (low CRF and high fat vs. high CRF and low fat, p<0.001).

Conclusions

These findings suggest that both body fat and CRF should be considered when interpreting CVD risk in Chinese children, while body fat may be correlated with CVD risk more than CRF.