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A central topic in Bioelectricity is the generation of the extracellular potential that results from the propagation of a transmembrane action potential along the muscle fiber. However, the way in which the extracellular potential is determined by the propagating action potential is difficult to describe, conceptualize, and visualize. Moreover, traditional quantitative approaches aimed at modeling extracellular potentials involve complex mathematical formulations, which do not allow students to visualize how the extracellular potential is generated around the active fiber. The present study is aimed at presenting a novel pedagogical approach to teaching the generation of extracellular potentials produced by muscle fibers based on the convolution operation. The effectiveness of this convolutional model was tested using a written exam and a satisfaction survey. Most students reported that a great advantage of this model was that it simplifies the problem by dividing it into three distinct components: 1) the input signal (associated with the action potential), 2) the impulse response (linked to the system formed by the fiber and the recording electrode), and 3) the output signal (the extracellular potential). Another key aspect of the present approach was that the input signal was represented by a sequence of electric dipoles, which allowed students to visualize the individual contribution of each dipole to the resulting extracellular potential. The results of the survey indicate that the combination of basic principles of electrical fields and intuitive graphical representations largely improves students' understanding of Bioelectricity concepts and enhances their motivation to complete their studies of biomedical engineering.

Introduction: The aims of this study were to examine cross-sectional, and longitudinal association of different measures of obesity and physical fitness with cardiovascular disease (CVD) risk factors in adolescents with Down syndrome. Methods: Longitudinal analysis included 90 adolescents with Down syndrome. Obesity and physical fitness were measured following the ALPHA battery. Blood pressure and blood samplings (glucose, total cholesterol, high-density lipoprotein cholesterol, and serum lipid triglycerides levels (mg/dl) were determinated. Results: In cross-sectional analyses, obesity was positively associated with single CVD risk factors and CVD risk factor index (all p < 0.05). In the prospective analyses, obesity was not associated with single CVD risk factors, but components of physical fitness at baseline impact in some single CVD risk factors (all p < 0.05). Conclusion: Obesity might be more strongly related to current cardiovascular-health, while components of physical fitness might be more related to future cardiovascular-health in adolescents with Down syndrome. [This article was written on behalf of the UP&DOWN Study Group.]

This study analyzed the factorial structure of motor competence tests designed to evaluate motor development among adolescents, focusing on the two main dimensions of coordination and motor control. To this end, we randomly sampled 1,026 adolescents (45.3% males; 45.7% females, age 13.75 years, SD = 1.28). Participants completed the Multidimensional Sportcomp Motor Battery, which features ten motor competence tests. Results indicate that two factors grouped seven of the ten sub-tests related to upper body strength and skill related-fitness. The factorial structure remained stable across age and sex groups, with the exception of manual grip (grip strength) and 7 Meters with Feet Together (jumping) which may relate to a sex-specific evolutionary pattern for upper body force. The Flexibility, Equilibrium and Lateral Jumps tests were not grouped by this factor analysis on any established dimension. These results underscore the multidimensionality of physical factors that influence motor competence among adolescents.

Objective: The aim of this study was to analyse the effect of 8 weeks of Pokémon GO on physical fitness (cardiorespiratory fitness [CRF], Speed/Agility [S/A], and muscular strength [MS]) and fatness (body mass index [BMI], percentage of body fat [%BF], and waist-hip index), as well as possible differences between weekly physical activity (PA) levels, in Spanish adolescents between 12 and 15 years of age. Design, setting and method: Comparative design, with a control group (n = 86) that did not participate in Pokémon GO, and an intervention group (n = 78) which did so over an 8-week period. Age, sex, number of home computers, and maternal educational level were controlled for as possible confounding variables. Results: Results show that players walked a total of 52 km in 8 weeks. Moreover, they played the game for a mean of 40 min/day. Pokémon GO players showed improvements in CRF and BMI (p < 0.05). Inactive young people showed a 22.2% increase in CRF and an 11.3% decrease in their %BF compared to non-players. Despite these results, less than half of the participants considered that Pokémon GO had improved their overall fitness and felt more encouraged to engage in PA. Conclusion: Pokémon GO increased PA and CRF levels and decreased BMI and %BF after 8 weeks of practice independently of age, sex, number of computers at home, and maternal education. The Pokémon GO app could be used in school and family contexts to increase the daily amount of MVPA, improve CRF, and to take advantage of the effects of loss of body fat.

Purpose: The aim of this study was to examine the short and long-term effects of a simple strength training program on muscle injury prevention in soccer players. Methods: Twenty-seven U-19 elite male soccer players participated in the study. The investigation was conducted over two consecutive and similar seasons (e.g., the same staff, players, weekly training schedule), the first being the control and the second the experimental season. The strength program was carried out 2 times per week, for 10 weeks, during part of the preseason and in-season. Injury incidence and absence days were compared between both seasons, according to the injury rate ratio (IRR), with 95% CI and the Z test. Results: A lower number of total and hamstring injuries were recorded during the experimental (9 and 2, respectively) compared to the control (15 and 7, respectively) period. During the 10 weeks intervention period, the injury rate ratio (IRR) was lower in the experimental season than in the control season (IRR = 8.12; 95% CI: 1.00-66.03; effect size (ES) = 3.30, large). In addition, there was a decline in absence days per injury and in the number of absence days/1000 h (IRR = 2.44; 95% CI: 1.90-3.14; ES = 1.12) during the experimental season. Conclusion: The results of this study suggest that this simple strength-training program could reduce the muscle injury incidence during its application period in young soccer players.

The purpose of this study was to analyze the kinematic variables that determine the performance of the standing long jump in children 6- to 12-years-old. There were 121 healthy children (58 girls) recorded while they performed the standing long jump test. All kinematic variables showed a significant correlation with calculated jump distance and measured jump distance, except for the knee joint angle at maximum shoulder extension angle, ankle joint angle at maximum shoulder extension angle, and shoulder joint angle at maximum knee flexion angle. Stepwise multiple regression analysis showed that sex, age, and body mass index accounted for 51.1% of the jump distance variance. Among all the kinematic variables, take-off distance and take-off speed were accounted for the most of the variation in the jump distance. Physical education teachers and coaches should consider special attention to these anthropometrics and kinematic aspects in improving the standing long jump performance in children.

The public health benefit of school physical education (PE) depends in large part on physical activity (PA) provided during class. According to the literature, PE has a valuable role in public health, and PA levels during PE classes depend on a wide range of factors. The main objective of this study, based on ecological models of behaviour, was to analyse what personal, psychosocial and environmental factors were associated with moderate to vigorous PA (MVPA) during PE lessons. The sample consisted of 189 adolescents (60.8% girls; M = 16.3 years, SD = 0.7) from nine high schools. PA was assessed by accelerometer. Differences in PA behaviour between the study groups were evaluated using the analysis of variance. Mixed-model regression analysis, adjusted for clustering within schools, evaluated the relation of each independent variable with MVPA. Results indicated that MVPA represented 21.5% of the total time of the session (11.8 minutes, SD = 5.3). Boys performed more MVPA than girls (13.6 versus 10.7 minutes), specifically during sessions in which fitness activities (cardiorespiratory endurance and strength), net games and sports were performed. The highest levels of MVPA occurred among students with high physical self-efficacy perception, when lessons were held outdoors, in schools with high socio-economic status, and during lessons with cardiorespiratory fitness activities and invasion games and sports. Gender, number of students per session and PE content were significantly related to MVPA according to regression analysis. Present findings show that PA levels during the PE sessions depend on several personal, psychosocial and environmental factors.

A few studies have recently reported that higher cardiorespiratory fitness is associated with higher volumes of subcortical brain structures in children. It is, however, unknown how different fitness measures relate to shapes of subcortical brain nuclei. We aimed to examine the association of the main health-related physical fitness components with shapes of subcortical brain structures in a sample of forty-four Spanish children aged 9·7 (sd 0·2) years from the NUtraceuticals for a HEALthier life project. Cardiorespiratory fitness, muscular strength and speed agility were assessed using valid and reliable tests (ALPHA-fitness test battery). Shape of the subcortical brain structures was assessed by MRI, and its relationship with fitness was examined after controlling for a set of potential confounders using a partial correlation permutation approach. Our results showed that all physical fitness components studied were significantly related to the shapes of subcortical brain nuclei. These associations were both positive and negative, indicating that a higher level of fitness in childhood is related to both expansions and contractions in certain regions of the accumbens, amygdala, caudate, hippocampus, pallidum, putamen and thalamus. Cardiorespiratory fitness was mainly associated with expansions, whereas handgrip was mostly associated with contractions in the structures studied. Future randomised-controlled trials will confirm or contrast our findings, demonstrating whether changes in fitness modify the shapes of brain structures and the extent to which those changes influence cognitive function. [ABSTRACT FROM AUTHOR]

Purpose: Health-related quality of life (HRQOL) in childhood is defined as an individual's subjective perception of the impact of health status on physical, psychological and social functioning. Nowadays, measuring of HRQOL has become an important outcome indicator in evaluating health-care. However, in younger children, the role of cardiorespiratory and other physical fitness components on HRQOL is unclear. The aims of this study were to analyse the association between components of physical fitness and HRQOL, as well as to determine which component of physical fitness was the best predictor of higher HRQOL.Methods: This was a cross-sectional study of 1413 schoolchildren (4 to 7 years old) from Spain. HRQOL was evaluated with the KINDL-R questionnaire for parents. Cardiorespiratory fitness, muscle strength and speed-agility were assessed using the ALPHA-Fitness battery. ANCOVA models were used to assess differences in HRQOL across physical fitness categories, controlling for age and BMI, by gender. Multiple linear regression was used to determine the independent association between the different physical fitness components and HRQOL.Results: Children with high physical fitness levels had better scores in physical well-being, school and total HRQOL score than those who had low physical fitness levels. The best predictor of HRQOL (total score) was muscular strength in boys and speed-agility among girls.Conclusions: Children with high physical fitness levels have higher HRQOL, although the association between components of physical fitness and HRQOL varies according to gender. Improving physical fitness could be a good strategy for improving HRQOL in children. [ABSTRACT FROM AUTHOR]

The purposes of this study were to examine how fitness at the baseline could predict both academic achievement and academic achievement changes one school year in advance. A total of 194 adolescents (mean age: 14.15 ± 0.97 years old, 112 boys) who attended secondary school participated in our study. Cardiorespiratory fitness was measured with the 20 m endurance shuttle-run test. We also assessed the lower-limbs muscular strength with the standing long jump test and flexibility with the sit-and-reach test. The academic achievement was assessed by school grades. We performed linear regression analyses. Additionally, we examined the relationship between fitness and changes in the academic performance following the same statistical methodology. Cardiorespiratory fitness was positively associated with mathematics one school year in advance (p = 0.025). Cardiorespiratory fitness was also positively associated with changes in Spanish language (p = 0.005), mathematics (p = 0.023), and the grade point average (p = 0.006). Muscular strength was also positively associated with changes in Spanish language (p = 0.040) and mathematics (p = 0.010), while flexibility was associated with changes in Spanish language (p = 0.039) and the grade point average (0.027). Our results suggest that cardiorespiratory fitness was positively associated with academic achievement in adolescents. [ABSTRACT FROM AUTHOR]

Summary: Background: North–south differences in the prevalence of obesity and fitness levels have been found in European adolescents, yet it is unknown if such differences already exist in very young children. Objectives: This study aims to compare the prevalence of overweight/obesity and fitness levels in preschool children aged 4 years from Sweden (north of Europe) and Spain (south of Europe). Methods: The sample consisted of 315 Swedish and 128 Spanish preschoolers. Anthropometry (weight, height, waist circumference) and fitness (strength, speed–agility, balance and cardiorespiratory fitness) were assessed. Analysis of covariance adjusted for age, sex and height/body mass index (BMI) was used. Results: Preschool children from Sweden had lower prevalence of overweight/obesity than their peers from Spain (World Obesity Federation, mean difference, MD = −9%, P = 0.010; World Health Organization, MD = −11%, P = 0.011). Concerning fitness, preschoolers from Spain were more fit in terms of upper‐muscular strength (MD = +0.4 kg, P = 0.010), speed–agility (MD = −1.9 s, P = 0.001), balance (MD = +4.0 s, P = 0.001) and cardiorespiratory fitness (MD = boys = +6.6 laps, girls = +2.3 laps; P < 0.001 for all), yet they had worse lower‐muscular strength (MD = −7.1, P ≤ 0.001) than those from Sweden. Differences in upper‐muscular strength were largely explained by differences in BMI, and differences in cardiorespiratory fitness should be interpreted cautiously due to some methodological deviations. Conclusions: These findings suggest that a higher prevalence of overweight/obesity in Spain compared with Sweden is present already at early childhood, while differences in physical fitness components showed mixed findings. [ABSTRACT FROM AUTHOR]

The authors discuss a study which has identified that the odds ratio of health status, low quality of family relationships and low academic performance is high among children and teenagers with low muscular fitness in Spain. They state that standardized measures for standing long jump test and throw basketball test have allowed for the computation of a muscular fitness index. The authors note that a condition beyond the absence of disease can be described by psychological positive health.

Background: The decrease in muscle mass and muscular strength and the increase in total body weight have significant implications for the health and functioning of postmenopausal women. Exercising in water has become increasingly popular as a means of delaying the physiological decline associated with age in middle-aged and older women. Research question: Is a 12-month aerobic and resistance water training program in a shallow pool effective in increasing muscle strength and decreasing total body weight in postmenopausal women? Type of study: Randomised controlled study. Methods: Thirty-eight subjects were randomly assigned to an exercise group (EG; n = 21) and a control group (CG; n = 17). The exercise group enrolled in a systematic aerobic and resistance training programme for 12 months performed at a frequency of 2 sessions per week, 45 minutes per session. Upper-extremity biokinetic strength and body mass index (BMI) were measured before and after the intervention. CG participants were physically active. Results: EG participants improved significantly (p 0.05) in mean force (MF: 7.92%), mean power (MP: 9.08%) and mean work (MW: 9.3%). Mean stroke length decreased significantly (p 0.05) in EG (-5.68%) and in CG (-11.5%). BMI was also significantly decreased (p 0.05) in EG participants (-2.75%). Conclusions: These results indicate that training in a shallow pool has significant implications for improving upper extremity muscular strength and total body weight in postmenopausal women. [ABSTRACT FROM AUTHOR]

Objective: Sarcopenia is a geriatric syndrome characterised by the progressive loss of skeletal muscle mass, muscular strength, and physical performance; it carries the risk of physical incapacity and reduced quality of life. This work reported the prevalence of sarcopenia in people aged ≥65 years, all in-patients at the Hospital Central de la Defensa Gómez Ulla, as determined by three sets of diagnostic criteria. The suitability of the indistinct use of these criteria sets was discussed., Methods: This was a cross sectional study. Sarcopenia was diagnosed depending on muscle mass, strength and functionality according to the European Working Group on Sarcopenia in Older People (EWGSOP), EWSOP2 and SARCF criteria. This study involved 295 people, all aged ≥65 years, and all of whom had been admitted to the above hospital between 1st March and 30th September 2018. Sampling was consecutive and performed at the internal medicine ward., Results: The overall prevalence of sarcopenia was 43.7% [95%CI 38-49.4%] according to the EWGSOP criteria, 28.5% [23.3-33.7%] according to EWGSOP2, and 37.6% [32-43.1%] according to SARCF. The EWGSOP criteria showed sarcopenia to be significantly more common among men than women (p<0.05)., Conclusions: The prevalence of sarcopenia recorded differed depending on the set of criteria used; they cannot, therefore, be used indistinctly for the diagnosis of this condition. Rather, given the results obtained, it would seem reasonable, in Europe, to continue using the EGSWOP criteria while research continues in this area., Competing Interests: Disclosure The authors report no conflicts of interest in this work.

The fat but fit paradox has suggested that obese individuals with good fitness levels have lower cardiometabolic risk compared to individuals with normal weight but lower fitness levels. This paradigm has not been explored in the context of bone health. The aim of this study was to test whether categories of fat but fit paradigm assessed by body fat percentage and handgrip strength holds up in young adults and to analyze the relationship between fat but fit categories and bone outcomes. Cluster cross-sectional analyses of data from 499 young adults aged 18 to 30 from Toledo and Cuenca, Spain were conducted. Body fat percentage, handgrip strength, bone mineral content (BMC), bone mineral density (BMD), and dietary nutrients such as, proteins, magnesium, calcium, phosphorus, potassium, and vitamin D were assessed. Cluster analysis of body fat percentage and handgrip z scores resulted in a classification of four clusters that could be interpreted according to Fat Unfit (FU), Unfat Unfit (UU), Fat Fit (FF) and Unfat Fit (UF) categories. ANCOVA models showed that young adults in clusters with higher handgrip strength levels (FF, UF) and with higher key bone nutrients levels (UF) had significantly higher total BMC values than their peers in the UU and FU cluster categories, after controlling for sex, age and height. This study provides two novel conclusions in relation to the fat but fit paradigm: first, it confirms the construct of the four clusters of body fat percentage and handgrip strength, and second, it reinforces the predictive validity of the fat but fit paradigm categories, indicating the positive effect, although it may not just be a causal relationship, of muscular strength and key bone nutrients on counteracting the negative effect of obesity on bone health.

The aim of the present study was to investigate the existence of a relative age effect (RAE) on physical fitness of preschoolers. Anthropometry and physical fitness were assessed in 3147 children (3-5 years old) using the PREFIT battery. Based on the birth year, participants were divided into 3year groups (3-, 4- and 5-years). Within each year group, 4quarter groups were created: quarter 1, preschoolers born from January to March; quarter 2, from April to June; quarter 3, from July to September; quarter 4, from October to December. The MANCOVA analysis revealed a main effect of year group (Wilks' λ = 0.383; F 10,5996  = 369.64; p < 0.001, η p 2  = 0.381) and of quarter (Wilks' λ = 0.874; F 15,8276.6  = 27.67; p < 0.001; η p 2  = 0.044) over the whole battery of tests. To the best of our knowledge, this is the first study to report the existence of RAE at the preschool stage. In general, performance improved as the relative age increased (i.e., those born in quarter 1 performed better than those in the other quarters). Individualization strategies should be addressed within the same academic year not only in elementary or secondary years but also in preschoolers.

Objectives: Reference values are necessary for classifying children, for health screening, and for early prevention as many non-communicable diseases aggravate during growth and development. While physical fitness reference standards are available in children aged 6 and older, such information is lacking in preschool children. Therefore, the purposes of this study were (1) to provide sex-and age-specific physical fitness reference standards for Spanish preschool children; and (2) to study sex differences across this age period and to characterise fitness performance throughout the preschool period., Design: Cross-sectional., Methods: A total of 3179 preschool children (1678 boys) aged 2.8-6.4 years old from Spain were included in the present study. Physical fitness was measured using the PREFIT battery., Results: Age- and sex-specific percentiles for the physical fitness components are provided. Boys performed better than girls in the cardiorespiratory fitness, muscular strength, and speed-agility tests over the whole preschool period studied and for the different percentiles. In contrast, girls performed slightly better than boys in the balance test. Older children had better performance in all fitness tests than their younger counterparts., Conclusions: Our study provides age- and sex-specific physical fitness reference standards in preschool children allowing interpretation of fitness assessment. Sexual dimorphism in fitness tests exists already at preschool age, and these differences become larger with age. These findings will help health, sport, and school professionals to identify preschool children with a high/very low fitness level, to examine changes in fitness over time, and to analyse those changes obtained due to intervention effects., (Copyright © 2018 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.)