Physical fitness and physical activity in obese and nonobese Flemish youth

Possible determinants of physical fitness in Japanese school children: A cross-sectional study

BACKGROUND

Physical fitness is one of the most important health indicators in children. Although appropriate body composition or certain lifestyle factors such as frequent physical activity are thought to improve physical fitness, results of previous studies are inconsistent, and most studies were from Western countries.

OBJECTIVES

We investigated associations of body composition and modifiable lifestyle factors such as physical activity, screen time, diet and sleep duration with physical fitness in Japanese primary school children.

METHODS

2308 children (age 10-12 years old) in 12 primary schools were analysed in this cross-sectional study. Physical fitness was evaluated by sports battery tests conducted routinely and annually at schools. The total score of sports battery tests, 20-m shuttle run (laps) and grip strength (kg) were selected as outcomes. Information about lifestyle factors was collected by two questionnaires. Associations between lifestyle factors and physical fitness were assessed by multivariable linear mixed models by sex.

RESULTS

Frequent exercise was related to better overall physical fitness. Regarding the 20-m shuttle run, many unfavourable lifestyle factors such as higher BMI in boys (β -7.37, 95% confidence interval [CI] -8.39, -6.35) and girls (β -3.54, 95% CI -4.50, -2.58), longer screen time (β -4.31, 95% CI -7.29, -1.34) in boys and girls (β -5.65, 95% CI -9.01, -2.30); shortest (reference) versus longest, breakfast skipping in boys (β -5.24, 95% CI -8.71, -1.77) and girls (β -3.57, 95% CI -6.84, -0.30); consumers (reference) versus skippers were associated with worse performance. Better quality of diet was associated with better results in the 20-m shuttle run only in girls (β 2.58, 95% CI 0.24, 4.93); lowest (reference) versus highest.

CONCLUSIONS

Frequent exercise was related to better physical fitness. Higher BMI and unfavourable lifestyle factors such as longer screen time and breakfast skipping were associated with worse results of the 20-m shuttle run.

Have the Fundamental Movement Skills of U.S. Children Changed?

Purpose: By using four national data sets, this study aimed to examine the changes in U.S. children's fundamental movement skills (FMS) from 1985 to 2019. Method: Three Tests Gross of Motor Development (TGMD) normative studies, i.e. TGMD-1 (N = 909, male% = 50), TGMD-2 (N = 1143, male% = 50) and TGMD-3 (N = 864, male% = 51), and the TGMD-2 data of the 2012 NHANES National Youth Fitness Survey (NNYFS-2012; raw N = 352, national represented population = 12,509,706, male% = 51) were used for analyses. Each item in TGMD-2/NNYFS and TGMD-3 was carefully examined, and these that did not match to TGMD-1 were deleted. Cohen's D effect size (ES) was utilized for the difference among year-to-year comparisons. Result: From 1985 to 2000, FMS in US children of 3-7 years old (90% increase & 10% no change) increased temporarily, but remained stable (17% increase & 83% no change) among 8-10 years old. Between 2000 and 2019, however, U.S. children began to demonstrate a slight/stable drop in FMS among 3-5 years old (22% decrease & 78% no change), and a distinct decline among 6-10 years old (80% decrease & 20% no change). While children with normal BMI showed the highest FMS score, the direct cause of reduction in FMS is still unknown. Conclusion: An overall up-and-down change was observed in U.S. children's FMS between 1985 and 2019, and more longitudinal studies with FMS-related variables are needed.

Cardiorespiratory and Muscular Fitness in Children and Adolescents with Obesity

PURPOSE OF REVIEW

Examine the current state of literature related to the impact of obesity in children and adolescents on health-related physical fitness and the resultant cardiometabolic disease risk.

RECENT FINDINGS

Cardiorespiratory fitness of children and adolescents has declined over the past few decades which corresponds with an increase in obesity rates. Children with obesity are more likely to have low cardiorespiratory fitness which is associated with higher cardiometabolic disease risk and poorer mental health. The impact of obesity on muscular fitness in children and adolescents is more difficult to ascertain, but in general measures of physical function are lower in children with obesity which has also been associated with higher cardiometabolic disease risk. Components of health-related physical fitness are trending negatively in children and adolescents and appear to be related to the increase in prevalence of obesity. The resultant cardiometabolic disease risk has also risen which suggests a greater disease burden in the future. These disparaging findings highlight the need for aggressive interventions to improve physical fitness in children and adolescents.

Is Frequency of Practice of Different Types of Physical Activity Associated with Health and a Healthy Lifestyle at Different Ages?

Physical activity (PA) has been shown to be related to physical and mental health. Yet there are few studies on how the frequency of PA relates to health and a healthy lifestyle. We aimed to investigate how the frequency of different PAs is associated with the following health indicators: body mass index (BMI), substance consumption, physical health, and mental health. We focused on three types of PA: (1) medium- to high-intensity aerobic exercise; (2) low- to medium-intensity relaxing exercise; and (3) outdoor leisure PA. A total of 9617 volunteers, aged 19 to 81, participated in the study. The relationships between the frequencies of the three types of PA and health-related and sociodemographic factors were analyzed using multinomial logistic regression. We found that women more frequently engaged in PA type 2, and men in types 1 and 3. A higher frequency of PA was associated with lower BMI and less or no smoking behavior; higher education (PAs 1 and 3); higher age (PAs 2 and 3); better physical health (PAs 1 and 3); and better mental health (PA 3). In conclusion, higher frequency of different PAs was significantly associated with better physical and mental health, less smoking, higher age, and a higher level of education.

Bone health, body composition and physical fitness dose-response effects of 16 weeks of recreational team handball for inactive middle-to-older-aged males - A randomised controlled trial

In this study we aimed at analysing the effects of different weekly exercise volumes (1, 2 or 3 times 60-min) on bone health, body composition and physical fitness of inactive middle-to-older-aged males, after 16 weeks of recreational team handball (RTH). Fifty-four men (68 ± 4 years, stature 169 ± 6 cm; body mass 78.4 ± 10.7 kg; fat mass 27.1 ± 5.3%; BMI 27.4 ± 2.9 kg/m2; VO2peak 27.3 ± 4.8 mL/min/kg) were randomised into three intervention groups (TH1, n = 13; TH2, n = 15; or TH3, n = 12, performing 1, 2 and 3 weekly 60-min training sessions, respectively), and a control group (CG, n = 14). The training sessions consisted mainly of RTH matches played as small-sided and formal game formats (4v4, 5v5, 6v6 or 7v7) with adapted rules. Matches' mean and peak heart rate (HR) ranged from 78-80% and 86-89%HRmax, respectively, and distance covered from 4676 to 5202 m. A time x group interaction was observed for procollagen type-1 amino-terminal propeptide (P1NP), osteocalcin (OC), carboxy-terminal type-1 collagen crosslinks (CTX), sclerostin, upper and lower body dynamic strength, right arm fat mass, left and right arm, right leg and android total mass (TM; p ≤ 0.047) with the greatest effects being shown for TH2 and TH3 groups. Post-intervention group differences were observed in CTX, left arm and right leg TM (TH3 > TH1), P1NP (TH2 > CG), OC, right arm TM (TH3 > CG), upper (CG < TH1, TH2 and TH3) and lower body dynamic strength (CG < TH1 and TH3) (p ≤ 0.047). RTH was effective in enhancing bone health, body composition and physical fitness in middle-to-older-aged males, especially for the intervention groups that performed 2-3 weekly training sessions.ClinicalTrials.gov ID: NCT05295511.Trial registration: ClinicalTrials.gov identifier: NCT05295511.HighlightsAfter 16 weeks of recreational team handball small-sided and formal matches, inactive middle-to-older-aged males improved bone health, body composition and physical fitness, by performing 1, 2 or 3 60-min weekly sessions, however, greater improvements were shown in the groups that performed 2 or 3 weekly training sessions.Training intensity was similar across the intervention groups that performed recreational team handball for 1, 2 or 3 60-min weekly sessions, which means that training volume is most likely to be the reason for the different health effects shown.The very high fun levels reported by all intervention groups shows that recreational team handball is a social and fun exercise modality for middle-to-older-aged males, with potential to intrinsically motivate the participants and assure long-term adherence to exercise.

START - physical exercise and person-centred cognitive skills training as treatment for adult ADHD: protocol for a randomized controlled trial

BACKGROUND

Core symptoms in attention deficit hyperactivity disorder (ADHD) are inattention, impulsivity and hyperactivity. Many individuals with this disorder also have a sedentary lifestyle, co-morbid mental illness such as depressive and anxiety disorders, and reduced quality of life. People with ADHD often have impaired executive function, which among other things may include difficulty in time management and structuring of everyday life. Pharmacological treatment is often the first-line option, but non-pharmacological treatment is also available and is used in clinical settings. In children and adolescents with ADHD, physical exercise is used as a non-pharmacological treatment. However, the evidence for the effectiveness of exercise in adults is sparse.

OBJECTIVE

To implement the START intervention (START = Stöd i Aktivitet, Rörelse och Träning [Support in activity, movement and exercise]) consisting of a 12-week, structured mixed exercise programme with or without a cognitive intervention, in adults with ADHD, and study whether it has an effect on core symptoms of ADHD as well as physical, cognitive, mental and everyday functioning compared with usual treatment. A secondary aim is to investigate the participants' experiences of the intervention and its possible benefits, and to evaluate the cost-effectiveness of START compared with usual treatment.

METHODS

This is a randomized controlled trial planned to be conducted in 120 adults with ADHD, aged 18-65. The intervention will be given as an add-on to standard care. Participants will be randomized to three groups. Group 1 will be given a physiotherapist-led mixed exercise programme for 12 weeks. Group 2 will receive the same intervention as group 1 with the addition of occupational therapist-led cognitive skills training. Group 3 will be the control group who will receive standard care only. The primary outcome will be reduction of ADHD symptoms measured using the World Health Organization (WHO) Adult ADHD Self-Report Scale (ASRS-v1.1), Clinical Global Impression-Severity scale (CGI-S) and CGI-Improvement scale (CGI-I). The effect will be measured within 1 week after the end of the intervention and 6 and 12 months later.

DISCUSSION

Data collection began in March 2021. The final 12-month follow-up is anticipated to be completed by autumn 2024.

TRIAL REGISTRATION

ClinicalTrials.gov (Identifier: NCT05049239). Registered on 20 September 2021 (last verified: May 2021).

Differences in the absolute muscle strength and power of children and adolescents with overweight or obesity: a systematic review

This study aimed to describe absolute muscle strength and power in children and adolescents with obesity, overweight and normal weight, and the assessment tests and tools used. We retrieved observational studies from MEDLINE (PubMed), TripDataBase, Epistemonikos, EBSCO essentials, NICE, SCOPUS, and LILACs up to February 2023. In addition, we recovered data from studies with at least three comparison groups (obesity, overweight, normal weight) and with a description of the absolute muscle strength and power and the assessment tests and instruments used. The methodologic quality of the studies was assessed with the Joanna Briggs checklist, and the review was carried out using the PRISMA 2020 methodology. Eleven studies with 13,451 participants from 6 to 18 years of age were once included, finding that the absolute muscle strength of their upper extremities was greater when they were overweight or obese; however, in the same groups, absolute muscle strength was lower when they carried their body weight. In addition, lower limb absolute muscle strength was significantly lower in obese participants than in normal weight, regardless of age and gender. The most used tools to measure the absolute muscle strength of the upper limbs were the grip dynamometers and push-up exercises. In contrast, different jump tests were used to measure the power of the lower limbs. There are great differences in muscle strength and power between overweight or obese children and adolescents and those with normal weight. Therefore, it is recommended to use validated tests, preferably that assess strength through the load of the patient's body weight, either of the upper or lower limbs, for greater evaluation objectivity that facilitates the management of these children and adolescents.

A Deep Learning Neural Network to Classify Obesity Risk in Portuguese Adolescents Based on Physical Fitness Levels and Body Mass Index Percentiles: Insights for National Health Policies

The increasing prevalence of overweight and obesity among adults is a risk factor for many chronic diseases and death. In addition, obesity among children and adolescents has reached unprecedented levels and studies show that obese children and adolescents are more likely to become obese adults. Therefore, both the prevention and treatment of obesity in adolescents are critical. This study aimed to develop an artificial intelligence (AI) neural network (NNET) model that identifies the risk of obesity in Portuguese adolescents based on their body mass index (BMI) percentiles and levels of physical fitness. Using datasets from the FITescola^® project, 654 adolescents aged between 10-19 years old, male: 334 (51%), female: n = 320 (49%), age 13.8 ± 2 years old, were selected to participate in a cross-sectional observational study. Physical fitness variables, age, and sex were used to identify the risk of obesity. The NNET had good accuracy (75%) and performance validation through the Receiver Operating Characteristic using the Area Under the Curve (ROC AUC = 64%) in identifying the risk of obesity in Portuguese adolescents based on the BMI percentiles. Correlations of moderate effect size were perceived for aerobic fitness (AF), upper limbs strength (ULS), and sprint time (ST), showing that some physical fitness variables contributed to the obesity risk of the adolescents. Our NNET presented a good accuracy (75%) and was validated with the K-Folds Cross-Validation (K-Folds CV) with good accuracy (71%) and ROC AUC (66%). According to the NNET, there was an increased risk of obesity linked to low physical fitness in Portuguese teenagers.

Muscle-to-Bone and Soft Tissue-to-Bone Ratio in Children and Adolescents with Obesity

OBJECTIVES

To explore the total and regional muscle-to-bone ratio in children and adolescents with obesity and compare the muscle-to-bone ratio (MBR) and soft tissue-to-bone ratio (SBR) to their peers with normal weight or overweight.

STUDY DESIGN

A total of 219 male and female pediatrics (mean age=12.3±2.5 years) participated in this study. Body composition was assessed with a total body dual X-ray absorptiometry. The MBR was calculated by dividing lean mass by bone mineral content. The SBR was determined by dividing the soft tissue mass (i.e., lean mass+fat mass) by bone mineral content. Differences in total and regional body composition measures between body mass index (BMI) percentile groups was assessed by ANOVA.

RESULTS

The obesity group had significantly higher MBR compared to the normal weight group for total (19.24±1.56 vs. 18.26±1.64), arm (17.11±1.67 vs. 15.88±1.81), and leg (18.41±1.68 vs. 16.62±1.55). Similarly, the obesity group had significantly higher MBR in the leg (18.41±1.68) compared to the overweight group (17.24±1.45). However, the overweight group was not significantly different from the normal weight or the obesity group for total and arm MBR. The total, arm, and leg SBR was significantly different between all BMI groups. Across the entire sample, MBR and SBR were negatively associated with high-density lipoprotein. SBR was positively associated with insulin, HOMA-IR, low-density lipoprotein, very low-density lipoprotein, triglycerides, and systolic blood pressure.

CONCLUSIONS

Children with obesity had a higher MBR and SBR compared to their normal weight peers. In addition, there were significant associations between SBR, higher levels of insulin, atherogenic lipoproteins, and increased systolic blood pressure. Thus, SBR may be useful as a marker for increased cardiometabolic disease risk, though more research in this area is warranted.

Assessment of the Relationship between Body Weight Status and Physical Literacy in 8 to 12 Year Old Pakistani School Children: The PAK-IPPL Cross-Sectional Study

(1) Background: Physical literacy (PL) is a multidimensional concept, since it fosters lifetime engagement in physical activities and reduces obesity; however, empirical evidence is lacking to support this association. This study first aimed to establish PL levels stratified by normal weight children and children with overweight and obesity. Furthermore, this study determined a correlation between PL domains and BMI by weight status among South Punjab school children. (2) Methods: This cross-sectional study involved 1360 (Boys: 675 and Girls: 685) children aged 8 to 12, and was conducted using CAPL-2. T-tests and chi-square were used to determine the difference between categorical variables, with MANOVA used to compare weight statuses. Spearman correlation was employed to determine the correlation between variables; p < 0.05 was considered significant. (3) Results: Normal weight children had significantly higher PL and domain scores, except for the knowledge domain. Most children with normal weights were at the achieving and excelling levels, while children with overweight and obesity were at the beginning and progressing levels. The correlation among PL domains in normal and overweight and obese children ranged from weak to strong (r = 0.001 to 0.737), and the knowledge domain was inversely correlated with the motivation domain (r = -0.023). PL and domain scores were inversely correlated to BMI, except for the knowledge domain. (4) Conclusions: Children with normal weight tend to have higher PL and domain scores, while those with overweight or obesity tend to have lower scores. There was a positive relationship between normal weight and higher PL and domain scores, and an inverse relationship was observed between BMI and higher PL scores.

The Impact of Obesity on the Fitness Performance of School-Aged Children Living in Rural Areas-The West Attica Project

This study aimed to investigate the relationship of body mass index (BMI) with muscle and cardiorespiratory fitness in children living within rural areas (regional unit of West Attica) in Greece. Participants included 399 students (187 boys, 212 girls), ages 8-12 years old, and were evaluated in physical performance tests. The point prevalence of overweight and obesity was 21.39% and 26.20% in boys, and 19.90% and 23.79% in girls. Significant differences were observed in all physical performance tests (handgrip, long jump, shuttle run, trunk flexors, and extensors endurance) between normal weight and obese participants. BMI was positively correlated with handgrip (r = 0.442-0.462, p < 0.001). There was a negative association with long jump (r = -0.206, p < 0.001), 20 m shuttle run (r = -0.394, p < 0.001), trunk flexors (r = -0.403, p < 0.001) and trunk extensors endurance (r = -0.280, p < 0.001). The regression analysis showed that 20-30% of the overall variation for physical performance assessments could be accounted for by BMI, age, and sex. With the exception of the long jump and the endurance of the trunk extensors, BMI alone may explain more than 10% of the outcome of most tests. This study highlights the determinant of BMI on muscle and cardiorespiratory fitness. The management of obesity should begin early in childhood to prevent adult chronic cardiovascular and metabolic diseases.

Relationship between body mass index and physical fitness of children and adolescents in Xinjiang, China: a cross-sectional study

Background

Xinjiang is an economically underdeveloped area in China, but the obesity rate of children and adolescents is increasing year by year. Physical fitness and body mass index (BMI) are very important factors for healthy development, whereas few studies focus on the relationship between them in this region. This study aimed to explore the relationship between physical fitness and BMI of children and adolescents aged 7 to 18 in Xinjiang.

Method

A total of 17,356 children and adolescents aged 7–18 years were involved. BMI was divided into five levels by percentiles, from very low to very high. Physical fitness was evaluated by five indicators: grip strength, standing long jump, sit-and-reach, 50 m dash, and endurance running. Single-factor analysis of variance was used to compare the Z-scores of the five physical fitness indicators among different BMI levels for the four age groups by gender. A nonlinear quadratic regression model was used to evaluate the relationship between BMI and each indicator in the four age groups.

Result

There is a significant correlation between the five health-related indicators (grip strength, standing long jump, sit and reach, 50 m dash, endurance run) at two age groups (13-15 yrs., 16-18 yrs) of children and adolescents in Xinjiang, China. The range of the Pearson coefficient is 0.048 ~ 0.744. For the other two age groups (7-9 yrs., 10-12 yrs.,) significant correlations are found only in some indicators, and the Pearson coefficient ranges from 0.002 to 0.589. The relationship between BMI and physical fitness presents an U-shaped or inverted U-shaped curve in most age groups(R² ranges from − 0.001 to 0.182. Children and adolescents with normal BMI score higher on physical fitness tests, and boys (R² ranges from − 0.001 to 0.182) are more pronounced than girls (R² ranges from 0.001 to 0.031).

Conclusion

Children and adolescents with a BMI above or below the normal ranges have lower physical fitness than those with normal BMI. BMI and physical fitness have an U-shaped or inverted U-shaped curve relationship, and the impact is more evident in boys than girls. Targeted actions such as improving the quality of physical education classes, advocating students to keep a balanced diet and physical exercise should be taken designedly.

Relationship between Asymmetry Indices, Anthropometric Parameters, and Physical Fitness in Obese and Non-Obese High School Students

Impaired balance is associated with an increased risk of lower extremity injuries. The purpose of this study was to investigate the relationship between age, anthropometric measurement, and asymmetry index (AI) in an adolescent high school population. Twenty-six male students (15 ± 1.0 years) were randomly selected. Body composition, measurements of vertical jump height using a countermovement jump test (CMJ), and dynamic single stance balance using the Y-balance test (YBT), were collected over 4 weeks. Hierarchical multiple linear regression analyses were used as dimension reduction techniques in four different blocks to determine valid predictors for AIs. In the first regression analysis, controlling for age, body mass, height, and body mass index (BMI), the regression coefficient (B = 0.383, 95% confidence interval [CI] [0.088, 0.679], p < 0.05) associated with body fat indicated that with each additional unit of body fat, the YBT AI increased by 0.383 units. In the second regression analysis, controlling for age, body mass, and BMI, the regression coefficients associated with height (B = -1.692, 95% CI [-3.115, -0.269], p < 0.05] and body fat percentage (B = 0.529, 95% CI [0.075, 0.983], p < 0.05) indicated that with each additional unit of height or body fat percentage, the CMJ AI decreased by 1.692 units and increased by 0.529 units. Grouping participants based on body fat percentage had a significant effect on the AIs (p < 0.05) of the CMJ and YBT. The AI of the CMJ was 15% higher, and that of the YBT was 7% higher in non-obese students than obese students. These findings contribute to the knowledge of the local community and the emerging body of literature on motor skills and competence related to weight in this population.

Relationships Between Sports Club Participation and Health Determinants in Adolescents and Young Adults

Physical fitness is a powerful marker of health in adolescents and young adults. The purpose of this study was to measure the relationships between age, sex, body mass index, and sports club participation on physical fitness. The population included 49,988 participants (23,721 girls and 26,267 boys) who were divided into five age groups (11–12, 13–14, 15–16, 17–18, and 19–21 years). Body mass index was calculated. Physical fitness was assessed with the Diagnoform^® Tonic battery. Sports club participation was also documented. The practiced sport was collected. The effects of age, sex, body mass index class, and sports club participation were tested. Boys' PF increased with age at a faster rate and was better than that of girls, except for flexibility (p < 0.001). For girls, a decrease was observed in endurance, speed and flexibility at 17-18 years. Sports club participation was greater for boys at every age. Obese participants had the lowest physical fitness and sports club participation. Sports club participation increased physical fitness. Team sports seemed best for improving physical fitness, except flexibility. The study shows that sports club participation may be a key element for building health in adolescents. Preventive healthcare projects that promote sports club are needed to target sports club dropouts (obese adolescents and girls). Bridges should be built between physical education classes and sports clubs in adolescence to improve the health status of young people.

Effects of a Physical Literacy Breaks (PLBreaks) Program on Physical Literacy and Body Composition in Portuguese Schoolchildren: A Study Protocol

(1) Background: Several studies have shown that active breaks have led to different improvements in their participants. However, no studies have assessed how they affect physical literacy (PL). (2) Aims: Therefore, this study will examine the effect of the PLBreaks programme on school children's PL and body composition. (3) Methods: A parallel-group randomised controlled trial will be conducted with assessments of PL (Canadian Assessment of Physical Literacy Development) and body composition (height, bodyweight, fat mass and fat-free mass) before and after an active breaks programme. PLBreak programme will run for 3 months and will be carried out 3 days a week for 20 min each day. The PLBreaks programme will consist of two blocks of 10 min of different physical activities (PA). The first block will be focused on the acquisition of knowledge and healthy life habits that will contribute to the development of the domains of knowledge and understanding and daily activity. The second block will be focused on physical competence and motivation throughout games. (4) Conclusions: The present study will investigate the efficacy of PLBreaks in schoolchildren in improving their PL and body composition. If the efficacy of the program is demonstrated, including the programme in public education programmes can be possible. This could be a scientific breakthrough in terms of health-related PA improvement and adherence, as well as the prevention of diseases associated with inactivity.

Potential Energy as an Alternative for Assessing Lower Limb Peak Power in Children: A Bayesian Hierarchical Analysis

The aim of this study was to analyze the use of potential energy (PE) as an alternative method to assess peak power of the lower limbs (PP) in children. 815 Spanish children (416 girls; 6–11 years old; Body Mass Index groups (n): underweight = 40, normal weight = 431, overweight = 216, obese = 128) were involved in this study. All participants performed a Countermovement Jump (CMJ) test. PP was calculated using Duncan (PP_DUNCAN), Gomez-Bruton (PP_GOMEZ) and PE_CMJ formulas. A model with PE_CMJ as the predictor variable showed a higher predictive accuracy with PP_DUNCAN and PP_GOMEZ than CMJ height (R² = 0.99 and 0.97, respectively; ELPD_diff = 1037.0 and 646.7, respectively). Moreover, PE_CMJ showed a higher linear association with PP_DUNCAN and PP_GOMEZ across BMI groups than CMJ height (β_PECMJ range from 0.67 to 0.77 predicting PP_DUNCAN; and from 0.90 to 1.13 predicting PP_GOMEZ). Our results provide further support for proposing PE_CMJ as an index to measure PP of the lower limbs, taking into account the children’s weight and not only the height of the jump. Therefore, we suggest the use of PE_CMJ in physical education classes as a valid method for estimating PP among children when laboratory methods are not feasible.

Associations between Fat Mass and Fat Free Mass with Physical Fitness in Adolescent Girls: A 3-Year Longitudinal Study

The main purpose of the study was to examine the longitudinal associations between fat mass and fat free mass with health-related physical fitness. Two-hundred and forty 15-year old adolescent girls were measured at the baseline and after a period of 3 years (17 years). Health-related physical fitness included the following tests: (1) explosive power of the lower extremities (standing broad jump); (2) muscle endurance of the trunk (sit-ups in 60 s); (3) flexibility (sit-and-reach test); (4) muscle endurance of the lower extremities (squats in 60 s); (5) aerobic endurance (the 800 m run test); and (6) speed endurance (the 400 m running test). Fat mass and fat free mass were assessed using the bioelectrical impedance method. Longitudinal associations were analyzed with linear mixed model estimates. After adjusting for body mass index, fat mass was negatively associated with standing broad jump (β = −1.13, p < 0.001), sit-ups in 60 s (β = −0.27, p < 0.001), and squats in 60 s (β = −0.27, p < 0001), while positive associations with the 800 m running test (β = 0.02, p < 0.001) and the 400 m running test (β = 0.02, p < 0.001) were observed. On the other hand, fat free mass was positively associated with standing broad jump (β = 1.14, p < 0.001), sit-ups in 60 s (β = 0.28, p < 0.001), and squats in 60 s (β = 0.28, p < 0001), while the 800 m running test (β = −0.02, p < 0.001) and the 400 m running test (β = −0.02, p < 0.001) exhibited negative associations. This study shows that fat mass and fat free mass components are longitudinally, but oppositely associated with health-related physical fitness in adolescent girls.

Effect of timing of school enrollment on physical fitness in third graders

Timing of initial school enrollment may vary considerably for various reasons such as early or delayed enrollment, skipped or repeated school classes. Accordingly, the age range within school grades includes older-(OTK) and younger-than-keyage (YTK) children. Hardly any information is available on the impact of timing of school enrollment on physical fitness. There is evidence from a related research topic showing large differences in academic performance between OTK and YTK children versus keyage children. Thus, the aim of this study was to compare physical fitness of OTK (N = 26,540) and YTK (N = 2586) children versus keyage children (N = 108,295) in a representative sample of German third graders. Physical fitness tests comprised cardiorespiratory endurance, coordination, speed, lower, and upper limbs muscle power. Predictions of physical fitness performance for YTK and OTK children were estimated using data from keyage children by taking age, sex, school, and assessment year into account. Data were annually recorded between 2011 and 2019. The difference between observed and predicted z-scores yielded a delta z-score that was used as a dependent variable in the linear mixed models. Findings indicate that OTK children showed poorer performance compared to keyage children, especially in coordination, and that YTK children outperformed keyage children, especially in coordination. Teachers should be aware that OTK children show poorer physical fitness performance compared to keyage children.

ACTIVITIES OF DAILY LIVING AND PARTICIPATION LIMITATION IN ADOLESCENTS WITH OBESITY

Purpose: Childhood obesity is one of the most severe public health problems in recent years. We aimed to compare physical fitness and activities of daily living (ADL)-participation limitations in adolescents with obesity and peers without obesity and investigate whether the differences in these parameters are affected by gender in this study. Methods: Fifteen adolescents with obesity and 16 adolescents without obesity included in this cross-sectional study. Physical fitness was determined using the Munich Physical Fitness Test (MFT) and Modified Shuttle Walk test (MSWT). ADL were determined using the TGlittre-P test, quality of life and participation was assessed using the Pediatric Outcomes Data Collection Instrument (PODCI). Results: The MSWT distance, peak oxygen consumption, and MFT total score were decreased in adolescents with obesity regardless of gender (p

Examination of Self-Esteem, Body Image, Eating Attitudes and Cardiorespiratory Performance in Adolescents

Self-esteem, body image and eating attitudes are important characteristics regarding adolescent mental health. In our present work, we aimed to investigate these psychological items in adolescent boys and girls examining gender differences and correlations with the BMI-for-age and cardiorespiratory performance. 374 students (209 girls with an average age of 16.4 ± 1.08 years, and 165 boys with an average age of 16.5 ± 1.03 years) underwent investigation using the Rosenberg self-esteem scale, EAT-26 and BAT questionnaires. The BMI-for-age was calculated with BMI growth charts and the cardiorespiratory performance was measured with the 20 m shuttle run test. Our results showed that adolescent girls scored lower self-esteem and higher values for BAT and each scale of eating behaviors, such as uncontrolled eating, cognitive restraints and emotional eating compared to boys despite the fact, that obesity and overweight were more common among boys. No significant correlation was found between BMI and psychological test results in either boys or girls, however, subjective body shape and gender predicted self-esteem and BAT scores and the cognitive restraints in the eating attitudes. Uncontrolled and emotional eating were primarily influenced by gender, in which BMI played only a weaker role. Cardiorespiratory performance was positively associated with self-esteem and body image among boys, and it had a negative correlation regarding BMI in both genders.

Children’s Changes in Perceptions and Body Composition Following a Family-Based Fitness Intervention

Physical fitness is associated with decreased weight in children, which helps improve youth obesity rates. Family programs can provide practical approaches to improving physical fitness for children. The purpose of this study was to assess the influence of a family-based fitness intervention on changes in body composition, fitness status, and perceptions of obese children. Families attended exercise and education sessions for 60–90 min once per week for 10 weeks. Participants consisted of 10 children who participated in semi-structured interviews, body composition, and fitness assessments at pre- and posttest. Following the intervention, results showed that children had a significant increase in sit-ups (p = .03, effect size = 0.79), lean mass (p < .001, Cohen’s d = 1.95), and bone mineral content (p < .001, Cohen’s d = 0.46). Using thematic analysis, four main themes emerged from the pre- and postintervention interviews: an increase in after-school and weekend intentional physical fitness, rules regarding sedentary behavior and screen time, more prevalent physical fitness reinforcements, and a shift in perception of exercise. Results from this study indicate a family-based intervention had an influence on children’s appreciation for and engagement in physical fitness, as well as healthy body composition and fitness outcomes.

Isokinetic trunk muscle performance in adolescents with different body mass indices

Objective

This study aims to evaluate the isokinetic performance for the peak torque and average power of the spinal flexor and extensor muscles in adolescents aged 12 to 18 years. The study also analyses the differences between the trunk muscle peak torque and average power with body mass index (BMI).

Method

The peak torque and average power of the trunk flexor and extensor muscles were measured in 180 adolescents (aged 12–18 years). The participants were classified into four groups according to BMI. The Biodex isokinetic dynamometer in concentric mode at speeds of 60° and 120°/sec was used for assessment.

Results

One-way multivariate analysis of variance MANOVA results demonstrated a significant difference in trunk muscle peak torque and average power with different BMI (F = 14.692, p = 0.0005). A Pearson's correlation analysis demonstrated a significantly negative correlation between weight and peak torque of trunk flexors and extensors (r = - 0.43, p = 0.0001; r = −0.31, p = 0.007, respectively). Finally, the results showed a negative correlation between weight and average power of trunk flexors and extensors (r = −0.54, p = 0.0001; r = −0.31, p = 0.007).

Conclusion

In this study, overweight and obese adolescents are found to be correlated with decreased trunk muscle torque and power. Thus, therapeutic interventions for overweight and obese adolescents, along with exercise training programmes, may help improve muscle performance including peak torque and power. Finally, these measures may enhance the quality of life of such adolescents.

Exercise training complementary to specialised early intervention in patients with first-episode psychosis: a feasibility randomised trial

Background

The aim of this study was to examine feasibility of trial processes and group-based, structured exercise training in patients with first-episode psychosis.

Methods

Twenty-five patients with first-episode psychosis took part in a two-arm randomised feasibility trial. They were individually randomised (1:1) via a computer-generated randomisation sequence and allocated to either an exercise intervention group (INT) or a control group (CON). Patients allocated to INT completed a physical exercise training programme at moderate-to-vigorous intensity, 1 h three times weekly for 8 weeks. CON patients were encouraged to continue their usual level of activity and were offered the training programme after 8 weeks. Primary outcomes included screening rate, recruitment rate, retention rate, attendance and adverse events. Secondary outcomes included heart rate response during training, cardiovascular health (VO_2max, resting heart rate, blood pressure), body composition (muscle mass, fat percentage), muscle strength (sit-to-stand, grip strength, jump height) and balance.

Results

Recruitment lasted 6 weeks and 86 out of 324 patients (27%) were screened, 71 of whom (83%) were deemed eligible. Twenty-five (35%) accepted inclusion (mean age 25.5; mean body mass index 25.1) and were subsequently randomised (INT = 13, CON = 12). Retention of patients was 76% and 52% at the 8-week and 16-week follow-up, respectively. Attendance was 43% (min. 9%, max. 96%). No significant changes were observed between groups in secondary physiological outcome measures.

Conclusions

Feasibility was challenged by limited recruitment and retention rates, suggesting that modifications are required if a large-scale randomised controlled trial is to be conducted. Recommendations for modifications are presented and discussed.

Trial registration

Clinicaltrials.gov, NCT03409393. Retrospectively registered.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40814-021-00900-5.

Influence of Body Composition on Physical Literacy in Spanish Children

BACKGROUND

Childhood obesity is a major health challenge in modern societies; therefore, prevention and management policies are needed. This study aims to establish the level of Physical Literacy (PL) in overweight and non-overweight children in Extremadura (Spain), analysing the potential differences between them and exploring their relationships with body composition.

METHODS

A single-measure cross-sectional study was performed with 135 children, who were taken anthropometric measurements and administered The Canadian Assessment of PL Development (CAPL-2) to assess their level of PL. The CAPL-2 covers four domains and participants to be classified into four levels: beginning, progressing, achieving, and excelling. Statistical analysis included descriptive and correlations.

RESULTS

Significant differences between overweight and non-overweight participants were found. Non-overweight participants had higher scores in all the domains included in PL, with the PL level of overweight children mainly being in the two lowest levels. Inverse correlations between body composition variables and PL in all domains (r from -0.223 to -0.507) were found, except for the knowledge domain.

CONCLUSIONS

Most of the non-overweight children had higher levels of PL than their overweight counterparts. The PL of overweight children was significantly lower compared to non-overweight children. Healthier body composition values were associated with a better PL.

Decreased Muscle-to-Fat Mass Ratio Is Associated with Low Muscular Fitness and High Alanine Aminotransferase in Children and Adolescent Boys in Organized Sports Clubs

Decreased muscle-to-fat mass ratio (MFR) is associated with pediatric nonalcoholic fatty liver disease (NAFLD) and may reduce muscular fitness. Regular exercise in sports clubs has not led to reductions in obesity in children and adolescents; they may have decreased MFR. Decreased MFR could cause reduced muscular fitness, which may put them at risk for NAFLD development. We investigated whether MFR is related to muscular fitness and serum alanine aminotransferase (ALT), to determine whether MFR could be used to screen for NAFLD in children and adolescent boys belonging to sports clubs. Altogether, 113 participants (aged 7–17 years) who underwent body composition, laboratory, and muscular fitness measurements during a medical checkup were divided into tertiles according to their MFR. Lower extremity muscular fitness values were significantly decreased in the lowest MFR tertile (p < 0.001); conversely, serum ALT levels were significantly increased (p < 0.01). Decreased MFR significantly increased the risk of elevated ALT, which requires screening for NAFLD, after adjusting for age, obesity, muscular fitness parameters, and metabolic risk factors (odds ratio = 8.53, 95% confidence interval = 1.60–45.6, p = 0.012). Physical fitness and body composition assessments, focusing on MFR, can be useful in improving performance and screening for NAFLD in children and adolescents exercising in sports clubs.

Effects of recreational team handball on bone health, postural balance and body composition in inactive postmenopausal women - A randomised controlled trial

This study reports the effects of a recreational team handball exercise programme (randomised controlled trial, RCT) on bone health, postural balance and body composition in inactive postmenopausal women without previous experience of the sport. Sixty-seven postmenopausal women (68.3 ± 6.2 years, stature 156.9 ± 5.8 cm, body mass 65.6 ± 9.6 kg, body fat 40.9 ± 5.9%, VO_2peak 25.2 ± 3.6 mL·min^-1·kg^-1) were randomised into team handball (THG, n = 41) and control (CG, n = 26) groups. During the 16-week intervention period, THG performed two to three 60-min training sessions per week, while CG continued with their habitual physical activity. Bone mineral density (BMD) and content (BMC), biochemical bone formation (osteocalcin (OC), procollagen type-1 amino-terminal propeptide (P1NP)) and resorption (carboxy-terminal type-1 collagen crosslinks (CTX)) markers, postural balance, body fat and lean mass were evaluated at baseline and post intervention. A time x group interaction (p ≤ 0.02) was shown for lumbar spine BMD (+1.5%) and BMC (+2.3%), P1NP (+37.6 ± 42.4%), OC (+41.9 ± 27.0%) and postural balance (-7 ± 37% falls), in favour of THG with no changes in CG. This RCT showed that short-term recreational team handball practice had an impact on bone turnover and was effective for improving bone health and postural balance in postmenopausal women without previous experience of the sport, hence potentially helping to reduce the risk of falls and fractures.

The Associations Between Physical Performance and Anthropometric Characteristics in Obese and Non-obese Schoolchild Handball Players

This study investigated the relationship of body fat and fitness measures in schoolchild handball players. Twenty-eight young male handball players from handball first youth league volunteered for the present investigation (age: 10.9 ± 0.72 years; body mass: 54.8 ± 22.9 kg; height: 1.48 ± 0.10 m; body fat: 27.6 ± 9.23%). Measures included the Yo-Yo Intermittent Recovery Test level 1 (Yo-Yo IR1), jumping ability [squat and counter-movement jumps (SJ, CMJ)], and sprint tests (10 m, 15 m). Anthropometry was assessed by body mass, body mass index (BMI), and fat percentage (%BF). The power of the upper limb was measured as the total distance thrown overhead using a 2 kg medicine ball. Intrarater reliability for all parameters showed a coefficient of variation (CV) below 10% and an intraclass correlation coefficient (ICC) above 0.75. All ICC were excellent (ICC ≥ 0.96). Reliability as shown by the CV differed between 1.0 (sprint 15 m) and 5.6 (sprint 10 m). With the exception of medicine ball throw, we found significant differences between non-obese and obese in all performance parameters. The differences ranged from η _p ² = 0.47 (sprint 10 m) to η _p ² = 0.09 (medicine ball throw). The two-step-linear regression analysis using the predictors body height and body weight (step 1) and body fat (step 2) showed a marked increase of explained variance by adding body fat. The largest r² changes were calculated for sprint 10 m (0.54), CMJ (0.49), and sprint 15 m (0.42). The lowest influence of the predictors was observed for medicine ball throw (step 1: r ² = 0.03, step 2: r ² = 0.07). With the exception of sprint parameters (β-coefficient sprint 10 m: -0.74; β-coefficient sprint 20: -0.66), a decrease of %BF leads to a higher performance in all parameters. %BF in youth handball players should be an important concern for practitioners working in this team sport in contrast to the frequently used BMI. It seems sensible and appropriate to engage very young children in physical activities such as team handball in order to improve their physical fitness. Decrease in% body fat could be considered both as a training and nutritional target to enhance and optimize sport performance-related outcomes.

The Relationship between Body Mass Index and Physical Fitness among Chinese University Students: Results of a Longitudinal Study

Over the past few decades, a gradual increase in sedentary lifestyles along with the increased consumption of a modern, hypercaloric diet has resulted in a substantial increase in the number of those classified as overweight or obese in China. The prevalence of overweight and obesity has become a key public health issue. However, it is important to be cautious when interpreting the literature as the majority of studies apply cross-sectional data to assess and subjectively compare the relationship between physical fitness and being overweight and obese. In the present study, longitudinal data were collected from 3066 students (enrolled in 2014) at a university in China at the beginning of each academic year throughout their four-year university program. The aim of this study was to analyze the various associations between BMI, explosive power, flexibility, and cardiorespiratory endurance, and a random-intercept panel model (RIPM) was separately employed on male and female participants to identify between- and within-person variations. In this way, the associations for between-person physical fitness and normal/overweight/obese weight ranges, and for within-person physical fitness and normal/overweight/obese weight ranges could be observed. The results of this study revealed that every physical fitness test chosen for evaluation (such as the standing long jump for explosive power or the distance run for cardiorespiratory endurance) was negatively related to the BMI results, irrespective of sex, with the notable exception of the flexibility results. In addition, this study showed that both males and females exhibited positively correlated results in both between-person BMI and flexibility as well as within-person BMI and flexibility. Furthermore, the relationships between and within persons of cardiorespiratory endurance, explosive power, and flexibility all showed positive correlations across both sexes. The dynamics between physical fitness and BMI identified in this study could prove useful to practitioners and researchers investigating such relationships in the future.

Obesity, the new childhood disability? An umbrella review on the association between adiposity and physical function

The adverse physical impacts of childhood obesity are increasingly being recognized. The objective of this study is to examine relationships between physical function and adiposity in youth. An umbrella review searched seven databases from inception to May 2019 for systematic reviews examining associations between adiposity and physical function in 0-20-year-olds. Findings were synthesized using the International Classification of Functioning, Disability and Health Framework and NHMRC FORM. Seventeen of 21 systematic reviews reported impairments to body function, including cardiorespiratory fitness (CRF), muscle function, balance/coordination, gait biomechanics, pain and injury. Six reviews reported activity restrictions in motor skills, running speed/agility and functional mobility, and two found inverse associations between adiposity and physical health-related quality of life (p-HRQOL). Some causal relationships indicated that adiposity inversely predicted p-HRQOL/CRF and CRF/muscle function inversely predicted adiposity. Assessments of physical function were heterogeneous and impacts on participation in life situations meaningful to the individual were largely unknown. Substantial evidence associates childhood overweight/obesity with reduced physical function. Associations were mainly cross-sectional, with causative evidence for some outcomes. Comprehensive physical function assessments by qualified health professionals are needed, along with targeted interventions to address deficits. Research should further examine causality of relationships, underlying mechanisms and participation challenges in real-life contexts.

Body Fat Is a Predictor of Physical Fitness in Obese Adolescent Handball Athletes

We examined the relationships between body fat (BF) and field measures of physical fitness in adolescent handball players. Twenty nine players (age: 16.6 ± 1.72 years; body mass: 79.8 ± 17.0 kg; height: 1.70 ± 0.12 m; body fat: 27.7 ± 8.67%) from Qatar handball first league performed a series of anthropometric and fitness tests related to their performance in sprinting (i.e., 15 m and 30 m sprint), jumping (i.e., countermovement and squat jumps), throwing (i.e., 3 kg medicine ball seated front throw) and running (i.e., agility T-Half and Yo-Yo intermittent recovery level 1 tests). Significant differences between obese and non-obese groups, classified based on age-stratified %BF norms, were found, with the largest difference being attributed to aerobic performance on the Yo-Yo test. Results indicated no significant relationships between anthropometric variables and sprinting or jumping abilities. %BF predicted a significant 8–15% portion in running performances of agility and aerobic capacity, while the latter were mainly explained by body height and mass. %BF was the only and strongest predictor of throwing performance, being an important determinant of performance in handball. Optimizing %BF should be considered as a training and nutrition goal in order to improve sport performance.

Italian Physical Fitness Decline: A True Fact or a Mindset? A 10-Year Observational Perspective Study

Evidence regarding a putative physical fitness decline remains less well documented for Italian children and adolescents. An update review of data collection articles was undertaken concerning motor performances (power, strength, speed-agility and indirect cardiorespiratory fitness) of children and adolescents worldwide and compared with 2859 11-12-year-old Italian students of both sexes, throughout a ten-year observational period. Lower limb explosive strength (standing broad jump), flexibility (sit-and-reach), endurance (Cooper) and speed (SP-30) performances of sixth grade Italian students showed nearly stable trends, with no differences during the observed decade, in both sexes. This 10-year perspective study confirmed that Italian physical fitness levels flatlined rather than actually declined. According to these study data, the decline in physical fitness of the Italian youth is ostensible and needs a further in-depth analysis.

Effects of physical training on anthropometrics, physical and physiological capacities in individuals with obesity: A systematic review

Increasing the amount of physical activity is an important strategy for weight loss. This systematic review summarizes recent findings on the effects of physical training on anthropometric characteristics, physical performances and physiological capacities in individuals with overweight and obesity. A systematic literature search strategy was conducted from inception until June 2019 using four electronic databases that identified 2,708 records. After screening for titles, abstracts and full texts, 116 studies were included in our final analysis. Both aerobic (e.g., endurance training) and anaerobic training (e.g., high-intensity training, resistance training) improved body composition and physical fitness indicators in adults, adolescents and children with obesity (effect size: 0.08 < d < 2.67, trivial to very large). This systematic review suggests that both low- and high-intensity training significantly reduced body weight and fat mass while increasing fat-free mass in individuals with obesity (effect size: 0.04 <d <3.2, trivial to very large). A significant increase in VO_2max also occurs in individuals with obesity in response to aerobic training or high-intensity interval training (effect size: 0.13 < d < 6.24, trivial to very large). Further studies are needed to define the optimal combination of training intensity and duration needed to produce the most efficacious results in individuals with obesity.

Effects of a physical activity program from diagnosis on cardiorespiratory fitness in children with cancer: a national non-randomized controlled trial

BACKGROUND

Children with cancer experience impaired cardiorespiratory fitness and physical function during and after treatment restricting their possibilities to engage in social activities including sport, leisure activities, and school. The objectives were to determine the effects of classmate-supported, controlled, supervised, in-hospital, physical activity program to preserve cardiorespiratory fitness and physical function from time of diagnosis in children with cancer.

METHODS

National non-randomized controlled trial including schoolchildren aged 6-18 years at diagnosis treated with chemo-/radiotherapy. We included 120 of 128 eligible patients (94%) in the intervention group (62.5% boys, 11.2 ± 3.1 years) from East Denmark and 58 patients in the control group (57% boys, 11.0 ± 3.2 years) from West Denmark. Eight children from the control group withdrew from participation. The groups were comparable in anthropometrics and cancer diagnoses (p > 0.05). The intervention consisted of (i) supervised in-hospital physical activity from diagnosis and throughout intensive treatment, (ii) 90-min general educational session on cancer and therapy in the child's school class, and (iii) selection of two classmates as ambassadors who took turns to support the child's physical training during the daytime. The primary outcome was cardiorespiratory fitness (VO₂peak, mL/min/kg) at 6 months after diagnosis (sex, age, diagnosis adjusted). Secondary outcomes were sit-to-stand, timed-up-and-go, handgrip strength, and balance test scores.

RESULTS

Ambassadors were identified for all, and 2542 individual and 621 group training sessions were held. VO₂peak deteriorated over time in the control group (- 0.17 [95% CI - 0.32 to - 0.02] per week, p = 0.02), but not in the intervention group (p = 0.14). At 6 months from diagnosis, VO₂peak was higher in the intervention group (29.6 ± 5.6 mL/kg/min) than in the control group (22.1 ± 5.6 mL/kg/min) (p = 0.01), and the intervention group had a better physical function at 3 and 6 months (p < 0.0001).

CONCLUSIONS

Peer-supported, supervised, in-hospital, physical activity is safe and feasible in children with cancer during treatment. Further, the results suggest that the intervention might mitigate impairments in cardiorespiratory fitness during treatment in children with cancer.

TRIAL REGISTRATION

The study was prospectively registered on the 11 January 2013. Clinicaltrial.gov NCT01772849 and NCT01772862 .

Influence of Body Composition on Physical Fitness in Adolescents

Background and objectives: Childhood obesity is one of the main public health issues facing advanced societies. The Spanish population presents 28.6% overweight or obese adolescents, and Extremadura, 22.3%. Physical fitness is considered one of the most important health markers and a common predictor of morbidity and mortality caused by cardiovascular diseases. Thus, fitness tests are needed for health monitoring, especially in overweight and obese adolescents. Therefore, this study aimed to explore the relationship between body composition and physical fitness in adolescents and to analyse if there are differences in physical condition and body composition between the sexes, as well as to compare the different body mass index (BMI) categories to each other. This project also tried to find regression equations to predict the physical fitness test results. Materials and Methods: A total of 225 adolescents were recruited. Weight status was classified according to WHO 2007 standards. Body composition variables (i.e., BMI, fat mass (FM), FM percentage (FM%), and fat-free mass (FFM)) and physical fitness (standing long jump (SLJ), speed–agility (SA), cardiorespiratory fitness (CF), and handgrip strength (HS)) were assessed. Results: Significant differences were found between the sexes in body composition (FM%, FM, and FFM) and physical fitness (SLJ, SA, CF, and HS) (p < 0.001) in favour of males. Significant differences were also found in speed (p = 0.002), CF (p < 0.001), and SLJ (p = 0.004) in favour of normal-weight adolescents compared to overweight and obese adolescents. Contrarily, the outcomes revealed a significantly greater HS (p = 0.014) in favour of overweight and obese participants compared to normal-weight adolescents. Moreover, the results showed that CF and SLJ correlated inversely with BMI, FM%, and total FM. There was also a direct relationship between SA and FM percentage, as well as between HS and FFM. Finally, four fitness test predictive models are proposed based on body composition, age, sex, and BMI. Conclusions: Overweight and obese adolescents have lower levels of physical fitness than their normal-weight peers, regardless of their sex. Normal-ranged body composition values are related to a greater physical fitness in adolescents. Furthermore, this study presents several equations that can help to predict the performance of different fitness tests in adolescents.

Hamstring extensibility differences among elite adolescent and young dancers of different dance styles and non-dancers

Background

Hamstrings have been analyzed extensively due to their tendency to shorten and their effect in the lumbo-pelvic dynamics and the sagittal position of the spine in trunk flexion with extended knees positions. It has been demonstrated that practicing a certain sport results in long-term changes in hamstring extensibility. Despite this, adequate extensibility of the hamstring musculature is essential for the dancer’s performance. Several studies have found differences in the extensibility of the hamstrings depending on the dance style, but none have compared ballet, Spanish dance and modern dance. The purpose of the present research was to analyze the differences in hamstring extensibility among professional dance students based on dance style practiced and non-dancers.

Methods

The sample was comprised of 210 students from the Professional Dance Conservatory (70 for ballet, 70 for Spanish dance and 70 for modern dance) and 70 non-dancers. For the assessment of hamstring extensibility, the angle in the passive and active straight leg raise (PSLR and ASLR, respectively) test, and the scores of the pelvic tilt in sit-and-reach (SR) test and the toe-touch (TT) test were randomly conducted.

Results

The results showed significant differences for all the tests according to group (p < 0.001). In the PSLR and ASLR test, for both legs, and in the pelvic tilt in the SR test, the ballet dancers showed greater ranges of hamstring extensibility than the modern dancers and Spanish dancers (p ≤ 0.001). In the distance in the SR test and in the pelvic tilt in the TT test, the ballet dancers obtained higher values than the Spanish dancers (p = 0.004 and p = 0.003, respectively). The modern dancers showed higher ranges of hip flexion than the Spanish dancers in the ASLR test for both legs and in the pelvic tilt in the SR test (p from 0.007 to <0.001). Dancers showed significantly higher hamstring extensibility than non-dancers in all the tests (p < 0.001).

Conclusions

The systematic practice of dance, regardless of the style, seems to lead to high ranges of hamstring extensibility. Ballet dancers have the greatest hamstring extensibility.

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

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

A 3-Week Multidisciplinary Body Weight Reduction Program Improves Body Composition and Lower Limb Power Output in 3,778 Severely Obese Children and Adolescents

The aim of the present study was to investigate the effects of a 3-week in-hospital body weight reduction program (BWRP), entailing moderate energy restriction, physical activity, psychological counseling and nutritional education, on body composition and lower limb muscle power (LLP) output in obese children and adolescents. Three thousand seven hundred seventy-eight obese [BMI: 36.2 ± 5.9 kg⋅m^–2; fat mass (FM): 42.7 ± 4.0%] children and adolescents (2,318 girls and 1,460 boys, aged 8–18 year) participated in this study. Before (T0) and after the end of the BWRP (21st day, T21), body composition was assessed by an impedancemeter and LLP by the Margaria stair climbing test. Body mass (BM) and FM significantly decreased in girls (-4.8 and –7.1%, p < 0.001) and in boys (-5.5 and -9.3%, p < 0.001) after 3-week BWRP, while fat-free mass (FFM) did not change significantly in both genders. LLP expressed in absolute values (W) significantly increased in girls (by mean 6.4% from age 13 to 18 year, P < 0.001) and in boys (by mean 7.2% from age 12 to 18 year, P < 0.001). LLP normalized to BM (W⋅kg^–1BM) significantly increased in girls (by mean 11.3%, P < 0.001) and boys (by mean 12.6%, P < 0.001) from age 9 to 18 year. As well, LLP normalized to FFM (W⋅kg^–1FFM) significantly increased in girls (by mean 9.1% from age 9 to 18 year, P < 0.001) and in boys (by mean 10.1% from age 10 to 18 year, P < 0.001). In conclusion, 3-week BWRP induces a significant decrease in FM and maintenance in FFM in obese children and adolescents, these effects being also associated with a significant increase of LLP both in absolute terms and when normalized to the BM or FFM.

Relationship between breakfast consumption, BMI status and physical fitness of Ghanaian school-aged children

BACKGROUND

Good nutrition and physical activity of school-aged children are important for ensuring optimum growth and reducing obesity. This present study assessed associations between breakfast consumption, BMI-for-Age (BMI) and physical fitness in a cross-section of school-aged children attending government-owned primary schools in Kumasi, Ghana.

METHOD

The sample consisted of 438 pupils (boys = 213; girls = 225; mean age 11.1 ± 1.1), attending 10 randomly selected schools. Weight (kg), height (cm) and Mid Upper Arm Circumference (MUAC) were measured for each participant, and BMI-for-age z-scores determined using the World Health Organisation (WHO) anthroplus software. Participants were stratified into thinness, normal weight, overweight/obese using WHO cut offs. Physical fitness was assessed using forward jump, left and right handgrips, flexibility, sit-ups and 50 metre run following standard procedures and converted to scores of 1 to 10 following Japanese standards, based on which percentiles were derived. Total fitness score for each pupil was computed by adding all scores. A questionnaire was used to assess meal intake patterns.

RESULTS

The mean BMI-for-age z-score for participants was - 0.24 ± 0.99. Thinness, normal weight and overweight/obesity were 2.7, 86.5, and 10.5% respectively among the pupils. Overweight was higher in girls (14.2%) compared to boys (4.2%), p = 0.003. Similarly, mean MUAC was significantly (p = 0.021) higher in the girls (22.0 ± 3.2 cm) than the boys (20.7 ± 7.3 cm). For physical fitness, the girls scored higher in forward jump (p < 0.0001), 50-m run (p = 0.002) and overall fitness score than the boys (21.0 ± 6.2 versus 19.2 ± 8.3, p = 0.012). However, a larger proportion of boys performed excellently and poorly than girls (p = 0.019). A positive correlation was observed between BMI z-score and hand grip (r = 0.21, p < 0.001), while sit up (r = - 0.11, p = 0.018) showed a negative correlation with BMI z-score. No other fitness test varied by BMI. Overweight children performed best in handgrip. Majority of children said they engaged in exercise (89.9%) and consumed breakfast (78.9%). Breakfast consumption was not associated with BMI z-score (x2 0.0359, p = 0.549) but non-breakfast consumers performed better in 50 m run compared to consumers (7.0 seconds ± 2.3 vrs 6.3 seconds ± 2.5, p = 0.022). Children who reported to exercise were physically fitter than those who did not.

CONCLUSION

Underweight levels were low while overweight was over 10% in these children. Girls were more than 3 times affected by overweight than boys, and were also physically fitter than boys. Breakfast consumption was not related to weight or fitness.

Beyond BMI: waist circumference and social environment is associated with motor performance ability in kindergartners

BACKGROUND

The aim of the current study was to examine the relationship between anthropometric characteristics (i.e. body height, body weight, body mass index [BMI] and waist circumference [WC]) with motor performance ability [MPA], social environmental factors of the district (i.e. employment status/working life, education, social situation/heterogeneity and home environment), where the respective kindergarten was located, as well as other potential health determinants in a representative sample of kindergartners.

METHODS

We analyzed data of 434 children aged 3 to 6 years which were obtained from a community-based cross-sectional health study conducted in the city of Mainz, Germany. Body height and weight, BMI and WC standard deviation scores [SDS] were calculated relative to the international proposed cut-offs of the IOTF. MPA was collected with multiple test items to determine coordination, speed strength, muscular endurance and speed. The life situation index [LSI] was used to assess the social environment of the district of the kindergarten. Adjusted for covariates, correlation and logistic regression analyses were conducted to estimate the effect of WC on MPA.

RESULTS

Below-average MPA was found in 46% of the sample. While there was no relationship to BMI (odds ratio [OR]: 1.09, 95% confidence interval [95% CI]: 0.83-1.44; p = 0.538), WC SDS was positively associated with below-average MPA (OR: 1.41, 95% CI: 1.01-1.95; p = 0.041). Further results show that the social environment of the district of the kindergarten was independently related to below-average MPA (OR: 2.72, 95% CI: 1.29-5.75; p = 0.009).

CONCLUSION

The findings suggest that WC rather than BMI is linked to measurements of MPA already in kindergartners and furthermore, there seems to be an independent association between MPA and the social environment of the district of the respective kindergarten.

Normative health-related fitness values for French children: The Diagnoform Programme

The primary objective of this study was to establish sex- and age-specific physical fitness percentiles for French children. The secondary aim was to assess sex, weight status, and age differences for physical fitness levels in French children. A sample of 31 484 children (16 023 boys, 15 461 girls) aged 6-11 years participated in the Diagnoform programme. Cardiorespiratory fitness, muscular endurance, speed, flexibility, and agility were assessed in this national programme. Percentile values were estimated as a function of age stratified by sex using a parametric method providing smooth centile curves and explicit formulae for the centile estimates. Values from the 10th to the 90th percentile are reported. The influence of body weight according to sex on the physical fitness level was also examined using an analysis of covariance adjusted for age. Physical fitness levels were slightly better in boys, except for agility and flexibility, in which girls performed better (Cohen's coefficient, 0.20-0.45; P < .001). All physical fitness tests were significantly associated with age (P < .0001). In general, overweight and obese children had a significantly poorer physical fitness level compared with their normal-weight counterparts (P < .05). No difference was found between thin and normal-weight boys and girls, except for agility (P < .05). Reference values provide normative data for French children, and these data should be useful for identifying special needs for appropriate intervention programmes.

Can anthropometry and physical fitness testing explain physical activity levels in children and adolescents with obesity?

OBJECTIVES

As time with patients and resources are increasingly limited, it is important to determine if clinical tests can provide further insight into real-world behaviors linked to clinical outcomes. The purpose of this study was to determine which aspects of anthropometry and physical fitness testing are associated with physical activity (PA) levels among youth with obesity.

DESIGN

Cross-sectional study.

METHOD

Anthropometry [height, waist circumference, bodyweight, fat percentage], physical fitness [muscular endurance (partial curl-ups), flexibility (sit-and-reach), lower-body power (long-jump), upper-body strength (grip), speed/agility (5×5-m shuttle), cardiorespiratory fitness (VO₂-max)], and PA [light (LPA), moderate (MPA), vigorous (VPA), MVPA] was assessed in 203 youth with obesity.

RESULTS

The sample was stratified by age <12 yrs (children); 12 yrs (adolescents) and sex. Stepwise regression evaluated associations between PA with anthropometry and physical fitness. Children (57% male) and adolescents (45% male) had a BMI Z-score of 3.5(SD:0.94) and 3.1(SD:0.76) respectively. Long-jump explained 19.5% [(Standardized) Beta=0.44; p=0.001] of variance in VPA for childhood girls and 12.6% (Beta=0.35; p=0.025) of variance in MPA for adolescent boys. 5×5-m shuttle explained 8.4% (Beta=-0.29; p=0.042) of variance in MVPA for childhood girls. Body mass explained 6.3% (Beta=-0.25; p=0.007) of variance in LPA in childhood boys. Fat percentage explained 9.8% (Beta=0.31; p=0.03) of variance in MPA in adolescent girls.

CONCLUSIONS

In conclusion, tests of lower body power, body mass and fat percentage provide limited information concerning PA levels in youth with obesity. Activity monitoring should be considered in addition to clinical assessments to more fully understand youth health.

Motor Competence Levels in Young Children: A Cross-Cultural Comparison Between Belgium and Greece

The targeted continent and/or country driven promotion of physical activity and health from an early age onwards requires more insight into cross-cultural differences in motor competence. Using the Bruininks-Oseretsky Test of Motor Proficiency, Second Edition Short Form (BOT-2 SF), this study assessed and compared both fine and gross motor skill performances of 5- and 6-year-old children from Belgium (n = 325) and Greece (n = 245). Linear mixed effect models and a χ2 test analyzed between-country differences in BOT-2 SF scores and the distribution across descriptive performance categories. Overall, Belgian and Greek participants displayed quite similar levels of motor competence, with fewer children performing (well-)below average than could be expected. On test item level, however, several significant differences emerged. Large effect sizes were found for knee push-ups (Hedges’ g = 1.46) and copying a square (Hedges’ g = 2.59), which demonstrated a better outcome for Belgian and Greek preschoolers, respectively. These findings might be attributed to different (physical) education practices in both European countries. The present study also highlights the importance of using an assessment tool covering the entire range of motor skills as well as a focusing primarily on raw performance scores, containing and explaining more variance, for international comparative research purposes.

Exploring Energy Expenditure and Body Movement of Exergaming in Children of Different Weight Status

PURPOSE

This study examined differences in energy expenditure and bodily movement among children of different weight status during exergames that varied in mode and intensity.

METHODS

Fifty-seven 8- to 12-year-old children including overweight/obesity (n = 28) and normal weight (n = 29) played three 10-minute interval Xbox One exergames (Fruit Ninja, Kung-Fu, and Shape Up) categorized based on predominantly upper-, whole-, or lower-limb movement, respectively. The authors measured bodily movement through accelerometry and obtained energy expenditure and metabolic equivalent (MET) via indirect calorimetry.

RESULTS

Energy expended during gameplay was the highest in Shape Up (P < .01) and higher in Kung-Fu than Fruit Ninja (P < .01). Absolute energy expenditure was significantly higher in overweight/obese children (P < .01), but not when controlling for body mass across 3 exergames (P > .05). Based on the MET cut-points, overweight/obese children spent more time at light intensity (<3 METs) for Fruit Ninja (P < .05) and Shape Up (P < .01), but less time at vigorous intensity (≥6 METs) for Kung-Fu (P < .01) and Shape Up (P < .01). Lower-limb movements during Shape Up were less in overweight/obese children (P = .03).

CONCLUSION

Although children in both groups expended similar energy relative to their body mass during gameplay, overweight/obese children spent more time at light intensity but less time at vigorous intensity with fewer movements especially while playing a lower limb-controlled exergame.

Effect of home-based strength training program on IGF-I, IGFBP-1 and IGFBP-3 in obese Latino boys participating in a 16-week randomized controlled trial

Introduction Growing evidence indicates that circulating concentrations of insulin-like growth factor 1 (IGF-I), along with IGF-I relative to IGF-binding proteins (IGFBP), are associated with an increased risk of cancer. In accord, regular exercise is linked with a lower risk of cancer. Purpose To assess the effects of a 16-week home-based strength training (HBST) program on serum IGF-I, IGFBP-1 and IGFBP-3. Methods A total of 32 obese Latino adolescent males (aged 14-18 years) were randomized into a twice-weekly HBST (n = 16) or a control group (C, n = 16) for 16 weeks. The following were measured at pre- and post-intervention: IGF-I, IGFBP-1 and IGFBP-3, glucose/insulin indices by oral and/or intravenous (IV) glucose tolerance tests, strength by one-repetition maximum (1RM), dietary intake by 3-d records, body composition by DEXA and physical activity using the Actigraph GT1X. The generalized linear model (GLM) was used to assess differences in changes among outcome measures between the HBST and C groups. Results Exercise adherence in the HBST group was 89%. IGF-1 showed a trend for significant within-subject improvements (p = 0.078) but no significant within-subject or between-subject differences for IGFBP-1, IGFBP-3 two-glucose, fasting glucose or 2-h glucose (p > 0.05). There was a significant decrease (p > 0.05) in fasting glucose in the C group (p = 0.02) and also in the intervention group (p = 0.03) between baseline and follow-up testing. A significant difference was also found in the C group for 2-h glucose with an increase at follow-up testing (p = 0.04). Conclusions Though not statistically significant (p < 0.05), the results indicated that a 16-week HBST program decreased IGF-I and increased IGFBP-1, along with IGFBP-3, concentrations among overweight/obese Latino boys. However, further studies should consider increasing either the dose or the duration of the intervention to elicit greater improvements in this at-risk pediatric population.

Understanding low adherence to an exercise program for adolescents with obesity: the HEARTY trial

INTRODUCTION

Despite efforts to improve adherence to physical activity interventions in youth with obesity, low adherence and attrition remain areas of great concern.

OBJECTIVE

The study was designed to determine which physiological and/or psychological factors predicted low adherence in adolescents with obesity enrolled in a 6-month exercise intervention study aimed to improve body composition.

METHODS

Three hundred four adolescents with obesity aged 14-18 years who volunteered for the HEARTY (Healthy Eating Aerobic and Resistance Training in Youth) randomized controlled trial completed physiological (body mass index, waist circumference, per cent body fat, resting metabolic rate and aerobic fitness) and psychological (body image, mood, self-esteem and self-efficacy) measures.

RESULTS

One hundred forty-one out of 228 (62%) randomized to exercise groups had low adherence (completed <70% of the prescribed four exercise sessions per week) to the intervention protocol. Logistic regression revealed that there were no baseline demographic or physiological variables that predicted low adherence in the participants. Appearance concern (a subscale of body image) (odds ratio [OR] 1.46, 95% confidence interval [CI]: 1.01, 2.1, P = 0.04), depressive mood (OR 1.12, 95% CI: 1.01, 1.23, P = 0.03) and confused mood (OR 1.16, 95% CI: 1.05, 1.27, P = 0.003) (two subscales of mood) were significant predictors of low adherence.

CONCLUSIONS

Adolescents with obesity who had higher appearance concerns and depressive and confused moods were less likely to adhere to exercise. Body image and mood should be screened to identify adolescents who may be at high risk of poor adherence and who may need concurrent or treatment support to address these psychological issues to derive maximal health benefits from an exercise programme.

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

INTRODUCTION

This study explored the relationship between physical fitness and indicators of physical and psychosocial health in a nationally representative sample of Canadian children and youth aged 6-17 years.

METHODS

We conducted a secondary data analysis of Canadian Health Measures Survey (Cycles 1 and 2; 2007-2011) data. The physical fitness measures included cardiorespiratory fitness (CRF; modified Canadian Aerobic Fitness Test), strength (handgrip strength), flexibility (sit-and-reach), and muscular endurance (partial curl-ups). The physical health indicators included directly measured biomarkers (total and HDL [high-density lipoprotein] cholesterol, C-reactive protein, glucose, and HbA1c [glycohaemoglobin]) and measures of adiposity, resting heart rate, and blood pressure. Psychosocial health was assessed using the Strengths and Difficulties Questionnaire. Multiple linear regressions were used to determine the association between variables, stratified by age groups and sex.

RESULTS

3,800 (48.9% female) children and youth were retained for this analysis. CRF displayed significant favourable associations with most physical health indicators in male and female participants. There were less significant favourable associations with flexibility and muscular endurance compared with CRF across age and sex groups. Strength was associated with higher adiposity in males and females, and lower heart rate in male children (β = -1.9; 95% CI: -2.9, -1.0) and female youth (β = -2.0; 95% CI: -2.7, -1.2). There were few significant favourable associations between measures of physical fitness and psychosocial health in this sample of children and youth.

CONCLUSION

These findings suggest that physical fitness, and especially CRF, is a significant indicator of physical health among Canadian children and youth aged 6-17 years.

The Relationships Between Weight Status and Physical Fitness Among Chinese Children and Youth

PURPOSE

This study examined the prevalence of different weight status and the relationships between weight status and physical fitness among Chinese children and youth.

METHODS

Participants were 107,206 Grade 4 children and 70,213 Grade 8 youth from the China National Assessment of Educational Quality - Physical Education & Health in 2015 (CNAEQ-PEH 2015). Using World Health Organization (WHO) and US Centers for Disease Control and Prevention (CDC) criteria, weight status was divided into four groups (underweight, normal weight, overweight, and obese) according to Body Mass Index (BMI). The differences of physical fitness performances (15-m progressive aerobic cardiovascular endurance run [PACER], standing long jump, and 50-m sprint) among four weight status groups were compared. Data were analyzed using descriptive statistics, MANCOVA, and Cohen's d.

RESULTS

The prevalence of weight status varied by criteria (e.g., for Grade 4 boys, the prevalence of underweight by WHO and CDC were 5.9% and 10.5%; overweight were 14.5% and 11.4%, respectively). Compared with the normal weight group, the selected physical fitness performances in the overweight and obese groups were worse (p < .001) with small to large effect sizes.

CONCLUSION

The prevalence of underweight and overweight/obese was relatively high among Chinese children and youth. The prevalence of underweight, overweight, and obesity varied slightly depending on the criteria used for evaluating BMI. The overweight/obese participants tended to perform poorer in selected physical fitness tests. The performance disparities between the normal weight group and overweight/obese groups were larger in Grade 4 than in Grade 8 and among boys than among girls.