Physical fitness components are bone mineral density predictors in adulthood: cross-sectional study.

BACKGROUND: Health-related physical fitness (HRPF) attributes are considered important markers beneficial to various health outcomes. However, the literature is divergent regarding HRPF and bone health in adulthood, especially due to the end of the second and beginning of the third decades of life when the peak bone mass period occurs. OBJECTIVE: To analyze which HRPF variables are areal bone mineral density (aBMD) predictors in adult males and females. METHODS: This study evaluated 137 healthy young adults aged 18-25 years (50% males). Dual-energy X-ray absorptiometry (DXA) was used to estimate fat mass and lean mass and aBMD, hand grip strength test, sit-ups test, flexibility test, lower limb muscle strength and 20-meter run were used to evaluate physical fitness. Multiple linear regression using the backward method was used to analyze bone mineral density predictors by sex. RESULTS: HRPF indicators showed correlations from R = 0.28 in the right femoral neck aBMD to R = 0.61 in the upper limbs aBMD in males; in females, correlations from R = 0.27 in total body aBMD to R = 0.68 in the lower limbs aBMD were found. In males, body mass and HRPF indicators were aBMD predictors with HRPF indicators explaining variance from R²=0.214 in the lumbar spine to R²=0.497 in the upper limbs, and in females, with the exception of the lumbar spine, variance from R²=0.237 in the right femoral neck aBMD to R²=0.442 in the lower limbs aBMD was found. CONCLUSION: Health-related physical fitness components were able to predict aBMD in different anatomical regions in young adults, especially muscle strength and cardiorespiratory fitness indicators for males, while only lean mass and fat mass for females.

Translation, validity and reliability of the fall risk scale for older adults.

INTRODUCTION: Falls in older adults are a common and serious threat to health and functional independence. It can cause psychological distress, inability to participate in activities of daily living, brain injury, fractures, and even death. The aim was to analyze the psychometric properties of the self-assessed fall risk scale (FRS) that measures the risk of falls in older adults in a central region of Chile, as well as to verify the concurrent validity against functional fitness tests. MATERIALS AND METHODS: A descriptive cross-sectional study was carried out in 222 older adults (OA) [34 males and 188 females] with an age range of 65 to 85 years. The 13-item self-perceived fall risk scale (FRS) was validated. Anthropometric measures (weight, height and waist circumference) were assessed. Five functional fitness tests were measured (right and left hand grip strength, biceps curl, up-and-go, agility and 6-minute walk test). Validation was performed by construct validation [(exploratory factor analysis (EFA) and confirmatory factor analysis (CFA)] and concurrent validity. RESULTS: The EFA revealed 4 factors in the FRS scale [1: fear of falling (variance 27.1%), 2: use of assistive devices (variance 10.6%), 3: loss of sensation (variance 9.3%), and 4: limited mobility (variance 8.3%)]. Factor loadings ranged from ∼ 0.50 to 0.83 across the 4 components. The Kaiser-Meyer Olkin sample adequacy test (KMO) reflected adequate adequacy (KMO = 0.79, chi-square (X2) = 498.806, gl = 78, p = 0.00). The CFA showed a satisfactory final fit [chi-square (X2) = 126.748, Root mean squared error of approximation (RMSEA) = 0.042, Tucker-Lewis Index (TLI) = 0.946, Comparative fit index (CFI) = 0.935 y Normed fit index (NFI) = 0.90. The relationships between the FRS scale and functional fitness tests (right and left hand grip strength, biceps curl, up-and-go, agility and 6-minute walk test) ranged from low to moderate (r= -0.23 to 0.41). CONCLUSION: The FRS scale showed acceptable validity and reliability in older adults in central region of Chile. It is expected that this scale will be useful for assessing fall risk in clinical and epidemiological settings in the aging Chilean population.

Estudio de revisión sistemática sobre el acoso escolar en el contexto de la educación y la actividad física / Systematic review study on bullying in the context of physical education and physical activity / Revisão sistemática de estudos sobre bullying no contexto da educação física e atividade física

Resumen: Introducción: las conductas agresivas como el bullying o acoso escolar (AE) en la población no son un hecho aislado y afecta gravemente la salud socioemocional de quienes lo padecen. Objetivo: el presente estudio tuvo por objetivo realizar una revisión sistemática de las publicaciones existentes sobre educación física (EF) y actividad física (AF). Materiales y métodos: se diseñó una investigación orientada con base en metodología PRISMA. La búsqueda de la información se desarrolló en cuatro bases de datos WOS, PUBMED, SCIELO y ELSEIVER entre los años 2015 al 2020. Resultados: un total de 53 artículos fueron encontrados, luego de analizados por los criterios de inclusión y exclusión, 18 estudios fueron considerados para su análisis. España, Brasil y Colombia concentran una mayor cantidad de publicaciones con gran variabilidad del tamaño de la muestra tanto para damas como varones principalmente, durante la adolescencia. Los conceptos más utilizados fueron bullying, victimización, violencia escolar, ciberacoso, autoestima dentro del contexto de EF y AF. Conclusión: se destaca la necesidad de visibiliza el problema en la EF y AF, por su impacto en materia de salud física, emocional y aprendizaje motriz.

Abstract: Introduction: aggressive behaviors such as bullying or School Bullying (SB) in the population are not an isolated event and seriously affect the socio-emotional health of those who suffer it. Objective: the aim of this study was to carry out a systematic review of existing publications on Physical Education (PE) and Physical Activity (PA). Materials and methods: a research was designed based on PRISMA methodology. The search for information was developed in four databases WOS, PUBMED, SCIELO and ELSEIVER between the years 2015 to 2020. Results: A total of 53 articles were found, after being analyzed by inclusion and exclusion criteria, 18 studies were considered for analysis. Spain, Brazil and Colombia concentrate a greater number of publications with great variability of sample size for both females and males mainly during adolescence. The most used concepts were Bullying; Victimization, School Violence, Cyberbullying, Cyberbullying, Self-esteem within the context of PE and PA. Conclusion: the need to make the problem visible in PE and PA is highlighted, due to its impact on physical and emotional health and motor learning.

Resumo: Introdução: Comportamentos agressivos, como bullying ou Bullying Escolar (BE) na população, não são eventos isolados e afetam seriamente a saúde socioemocional daqueles que o sofrem. Objetivo: O objetivo deste estudo foi realizar uma revisão sistemática das publicações existentes sobre Educação Física (EF) e Atividade Física (AF). Materiais e métodos: Foi desenhada uma pesquisa baseada na metodologia PRISMA. A busca por informações foi desenvolvida em quatro bases de dados: WOS, PUBMED, SCIELO e ELSEVIER, entre os anos de 2015 a 2020. Resultados: Um total de 53 artigos foram encontrados; após serem analisados pelos critérios de inclusão e exclusão, 18 estudos foram considerados para análise. Espanha, Brasil e Colômbia concentram um maior número de publicações com grande variabilidade de tamanho de amostra para ambos os sexos, principalmente durante a adolescência. Os conceitos mais utilizados foram Bullying; Vitimização, Violência Escolar, Cyberbullying, Autoestima dentro do contexto de EF e AF. Conclusão: Destaca-se a necessidade de tornar visível o problema na EF e AF, devido ao seu impacto na saúde física e emocional e na aprendizagem motora.

Phase angle and its determinants among adolescents: influence of body composition and physical fitness level.

To examine the association between levels of physical fitness, parameters of body composition and phase angle (PhA) amongst adolescents. A total of 152 adolescents (84 girls) aged 11-16 years were included in this study. Weight and height were measured and the body mass index (BMI) was calculated. Bioelectrical impedance analysis (BIA) provided resistance and reactance parameters to calculate fat-free mass (FFM), PhA and fat mass (%FM). The following physical fitness variables were analysed: flexibility, abdominal muscular endurance, upper and lower limb explosive strength, agility, speed and cardiorespiratory fitness. Generalized Linear Models were applied to verify differences across sexes. Stepwise linear regression was used to establish an association between the variables studied. The study established an association between PhA and weight, FFM, BMI, FM, %FM and medicine ball throw (MBT) for girls. As for the boys, an association was verified between PhA and weight, FFM, BMI, standing long jump (SLJ), MBT and the three allometric VO2peak variables analyzed. An association was found between PhA and the boys' 4-m shuttle run test (4SRT) and 20-m sprint test (20SRT). Boys showed a greater phase angle than girls; In girls, BMI and %FM, were determinant of 32.4% (r = 0.57). PhA variability which is influenced by physical fitness, body composition and, therefore, the tissues electrical conductivity. Furthermore, boys' height, FFM, upper limb strength, and agility account for 58.4% (r = 0.76) PhA variability. There was a positive correlation between the physical fitness tests and the PhA.

Bibliometric study of the scientific productivity of the COVID-19 impact on constructs affecting happiness in university students.

COVID-19 has caused a wide range of psychological problems, such as panic disorders, anxiety, and depression. Knowing what others have researched on, what constructs they have focused on, will (a) summarize published information, (b) help identify research gaps, and (c) encourage future research that addresses these gaps. The aim of the study was to analyze the bibliometric indicators of scientific productivity of the impact of COVID-19 on constructs affecting undergraduate happiness. A bibliometric study was conducted. The PubMed database was used. Data summarized were: authors, year of publication, journal name, country, language of publication, and subtopic addressed. A total of 16 English-language studies were identified between April 2022 and December 2022. There were 12 countries that have published on the impact of COVID-19 on constructs affecting college students' happiness. Most of the studies were developed in the United States (n = 4, 25%) and China (n = 2, 12.5%). Thirteen journals publishing these topics were detected. The subtopics considered were organized into nine categories (e.g., a: Psychological impact, b: Adverse childhood experiences, c: Stress, d: Personality traits, e: Perception of the educational environment, f: Spiritual health, g: Distress, h: Uncertainty and socioemotional learning, i: Satisfaction with life). This study suggests that the number of countries and scientific journals that have published on the impact of COVID-19 on constructs affecting college students' happiness is small. In addition, the most discussed subtopics during the pandemic were related to constructs such as psychological impact and stress affecting college students' happiness.

Functional fitness benchmark values for older adults: a systematic review.

Introduction: The use of normative values and/or standards of functional fitness in adults is relevant to overall health and well-being. The objectives of the study were: to identify the physical tests of the senior fitness test (SFT) that have been applied since its proposal and to describe the proposed percentiles according to age, sex and country. Methods: A systematic review study was conducted in the Pubmed and Scopus databases. As eligibility criteria, we considered the period from 1999 to 2022 that presented data on SFT test used in the population over 60 years of age and that described normative values through percentiles. MeSH were used as: (1) Physical fitness, Exercise test, Senior Fitness Test, Functional fitness, Cardiorespiratory fitness, (2) older adult, aged, (3) Reference standards, standards, standards of care. Boolean operators "AND" and "OR" were included. Data extracted from the selected studies included: year of publication, country, sample age, sample size, sample sex, fitness component. Results and discussion: Seven studies were identified in five countries (03 in China, 01 in Poland, 01 in Portugal, 01 in Spain and 01 in United States). The age range ranged from 60 to 103 years. The studies were conducted in both sexes. The study with the smallest sample size was by Chung et al. (China) with 944 participants and the largest number of participants was the study by Rikli and Jones in the United States with 7,183 participants. In general, no study was able to complete 100% (8 components) of the tests proposed in the SFT. Normative values were presented through percentile distribution (p10, p50 and p90) organized by age ranges. Males presented better performance in FPF tests than females in all tests. Since the first publication of the SFT until 2022, seven articles have been published in countries such as United States, China (three regional studies), Poland, Portugal and Spain. No study has published the complete battery with its eight components. The percentiles of functional fitness reflect decline with advancing age. Systematic review registration: PROSPERO (CRD42023441294: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023441294).

Parameters of pubertal growth spurt in children and adolescents living at high altitude in Peru

Abstract Objectives: The aim was to estimate the pubertal growth height of children and adolescents living in a high-altitude region of Peru using the Preece-Baines model 1 (1 PB). Methods: A cross-sectional study was conducted in schoolchildren from the department of Puno (Peru) between 3841 and 3874 masl. The age range was between 4 and 17 years. Standing height was evaluated. 1 PB was used to infer the mathematical and biological parameters of stature. Results: Mathematical parameters estimated by the 1 PB model reflected small residual standard error (RSE) values in both sexes (0.25 in boys and 0.27 in girls). In boys, the age at which peak velocity was reached (APHV) was estimated at 13.21 ± 0.33years. While in girls it was 9.96 ± 0.26years (p < 0.05). In general, girls reached APHV (y) 3.25 years earlier than boys. On the other hand, the growth velocity of maximum height [APHV (cm/y)] of boys was higher (6.33 ± 6.06 cm/y) relative to girls (6.06 ± 0.32 cm/y). Estimated final adult height (EFAH) in boys was reached at 166.020 ± 0.99 cm and height at maximum growth velocity (HPHV) was 153.07 ± 0.67 cm, while in girls they were significantly lower (EFAH; 153.74 ± 0.44 cm and HPHV: 139.73 ± 0.84 cm). Conclusions: This study showed that girls living in Puno at a high altitude in Peru reached APHV 3 years earlier than boys and at the same time reflected slower PHV. These results suggest that pubertal growth at high altitudes is slower in both sexes and especially in girls. Thus, modeling physical growth may be an important step in understanding the onset of puberty at different latitudes.

Prediction of fat-free mass from body surface area in young basketball players.

BACKGROUND: Fat Free Mass (FFM) is an important and essential indicator in various sports populations, since greater muscle and bone mass generates greater strength, endurance and speed in athletes. OBJECTIVE: The purpose of the study was to validate Body Surface Area (BSA) as an anthropometric indicator to estimate FFM in young basketball players. METHODS: A descriptive cross-sectional study was carried out in 105 male basketball players of the Brazilian Basketball Confederation of Sao Paulo (Campinas), Brazil. The age range was 11 to 15 years. Weight and height were evaluated. BSA, body mass index (BMI) and maturity status (MS) were calculated. Total body scanning was performed by dual X-ray absorptiometry (DXA). The components were extracted: Fat mass (FM), Fat free mass (FFM), percentage of fat mass (%FM) and bone mass (BM). The data were analyzed using the correlation coefficient of concordance (CCC) in terms of precision and accuracy. RESULTS: Three regression equations were generated: equation 1 had age and body weight as predictors [FFM= -30.059+(2.926*age)+(0.625*Weight)] (R2 = 92%, precision = 0.96 and accuracy = 0.99), equation 2 used age and BSA [FFM=-45.719+(1.934*age)+(39.388*BSA)] (R2 = 94%, precision = 0.97 and accuracy = 0.99) and equation 3 was based on APHV and BSA [FFM=-15.284+(1.765*APHV)+(37.610*(BSA)] (R2 = 94%, precision = 0.96 and accuracy = 0.99). CONCLUSIONS: The results suggest the use of anthropometric equation using decimal age and BSA to estimate FFM in young basketball players. This new method developed can be used to design, evaluate and control training programs and monitor the weight status of athletes.

Reference values for the 6-min walking test in children and adolescents living in a moderate altitude region of Peru.

BACKGROUND: The assessment of cardiorespiratory fitness is important because it allows the identification of subgroups with poor health status and the targeting of effective intervention strategies to improve health. OBJECTIVE: To compare the cardiorespiratory capacity of children and adolescents living in a moderate altitude region of Peru with international studies and to develop reference values for the 6-min walk test (6MWT) according to age and sex. METHODOLOGY: A descriptive cross-sectional study of schoolchildren from a region of moderate altitude in Peru was carried out. A total of 704 schoolchildren (400 males and 304 females) with an age range of 6 to 17 years were studied. Weight, standing height, waist circumference (WC), body mass index (BMI) and tri-ponderal mass index (TMI) were evaluated. The 6MWT was assessed in a straight line over a distance of 30 m. Percentiles were created through the LMS method [L (skewness: lambda), M (median: mu) and S (coefficient of variation: Mu)]. RESULTS: There were discrepancies in cardiorespiratory fitness performance with international studies by age and sex. The schoolchildren in the study reached stability and the highest number of meters in the last two age ranges (14 to 15 years: 698.1 m and 16 to 17 years 686.3 m in males). While females (14 to 15 years: 698.1 m and 16 to 17 years: 686.3 m). The proposed percentile values show ascending values as age advances. The cut-off points adopted are: low cardiorespiratory fitness < p25, moderate p25 to p75 and high cardiorespiratory fitness p > 75. CONCLUSION: We verified that the cardiorespiratory fitness evaluated by means of the 6MWT is ascending with the course of age. Even the performance with other countries is heterogeneous at early and middle ages, stabilizing during adolescence. The proposed reference values can be used to evaluate and monitor cardiorespiratory fitness during physical education classes.

Parameters of pubertal growth spurt in children and adolescents living at high altitude in Peru.

OBJECTIVES: The aim was to estimate the pubertal growth height of children and adolescents living in a high-altitude region of Peru using the Preece-Baines model 1 (1 PB). METHODS: A cross-sectional study was conducted in schoolchildren from the department of Puno (Peru) between 3841 and 3874 masl. The age range was between 4 and 17 years. Standing height was evaluated. 1 PB was used to infer the mathematical and biological parameters of stature. RESULTS: Mathematical parameters estimated by the 1 PB model reflected small residual standard error (RSE) values in both sexes (0.25 in boys and 0.27 in girls). In boys, the age at which peak velocity was reached (APHV) was estimated at 13.21 ± 0.33years. While in girls it was 9.96 ± 0.26years (p < 0.05). In general, girls reached APHV (y) 3.25 years earlier than boys. On the other hand, the growth velocity of maximum height [APHV (cm/y)] of boys was higher (6.33 ± 6.06 cm/y) relative to girls (6.06 ± 0.32 cm/y). Estimated final adult height (EFAH) in boys was reached at 166.020 ± 0.99 cm and height at maximum growth velocity (HPHV) was 153.07 ± 0.67 cm, while in girls they were significantly lower (EFAH; 153.74 ± 0.44 cm and HPHV: 139.73 ± 0.84 cm). CONCLUSIONS: This study showed that girls living in Puno at a high altitude in Peru reached APHV 3 years earlier than boys and at the same time reflected slower PHV. These results suggest that pubertal growth at high altitudes is slower in both sexes and especially in girls. Thus, modeling physical growth may be an important step in understanding the onset of puberty at different latitudes.

Reference values for body composition and physical fitness of young Brazilian elite soccer players.

Objective: a) to verify whether body composition and physical fitness should be analyzed by chronological age and/or maturity stage in young Brazilian soccer players and b) to propose reference values for the evaluation of body composition and physical fitness by maturity stage in elite soccer players. Methods: A descriptive-correlational study was carried out in 206 young Brazilian soccer players (11-16 years old). The sample selection was non-probabilistic by convenience. Weight and standing height were evaluated. Body composition (BC) was assessed by dual X-ray absorptiometry (DXA). BC indicators [(percent fat (%F), Fat-free mass (FFM), Fat mass (FM) and Bone mass (BM)] were extracted. For physical fitness (PF), we applied the Flexibility (cm) sit and reach tests, explosive strength tests [Counter Movement Jump CMJ (cm) and horizontal jump HJ (cm)], speed [Speed 10, 20, 30 and 40 m (seconds)] and Yo-Yo endurance level I test. Percentiles were constructed for BC and PF using the LMS method [L (Lambda; skewness), M (Mu; median) and S (Sigma; coefficient of variation)]. Results: The explanatory power between chronological age (CA) with BC was: FM (R2 = 0.03%), FFM (R 2 = 0.66%) and BM (R 2 = 0.62%), while between maturity status (MS) with BC were: FM (R 2 = 0.04%), FFM (R 2 = 0.71%) and BM (R 2 = 0.66). The explanatory power between the CA with the physical fitness tests ranged from: (R 2 = 0.22-0.62%). While between MS with physical fitness the values ranged from: (R 2 = 0.23-0.64%). Percentiles per MS (P3, P5, P10, P15, P25, P50, P75, P85, P90, P95 and P97) were proposed for both BC and PF. Conclusion: The results of the study have shown that the evaluation of BC and PF of young soccer players should be performed by controlling for MS rather than for CA. The inclusion of a non-invasive method to control MS by means of percentiles during puberty may contribute to the development of retention and exclusion of young soccer players, thus, they may have a better chance of achieving sporting success.

Comparison of social isolation in autistic children and adolescents according to age, marital status and number of siblings.

BACKGROUND: Children and adolescents with autism spectrum disorder (ASD) have difficulties that limit their opportunities to interact with peers and family members. These behaviors can lead to social exclusion, and consequently social isolation. The aim was to compare social isolation of children and adolescents with ASD according to age, marital status, and number of siblings. MATERIALS AND METHODS: Cross-sectional descriptive study in 37 subjects with ASD. Social isolation was assessed using a 6-item scale (with five alternatives). The sociodemographic variables were age, sex, marital status of parents, and number of siblings. Two groups were formed according to age (children from 4 to 10 years old and adolescents from 11 to 20 years old). RESULTS: For the total score of the social isolation scale, children showed a higher score (21.1 ± 4.7) than adolescents (17.7 ± 5.7). Children living with divorced parents had lower scores (16.2 ± 3.6), compared to married (22.2 ± 4.5) and cohabiting (22.8) children. For the number of siblings, with no siblings 17.2 ± 3.1 points, one sibling 22.2 ± 3.5 points, two siblings 22.1 ± 3.1 points, and three siblings 22.4 ± 3.2 points (P < 0.05). Age was related to social isolation (r = -0.30, P < 0.05). CONCLUSION: Children who live with divorced parents and have no siblings presented a higher degree of isolation in relation to their counterparts who live with both parents and have at least one sibling. Age plays a relevant role, with children aged 4-10 years presenting a lower degree of isolation than the adolescent group. It is suggested that the preservation of a functional family and the presence of siblings could contribute to improving social isolation.

Bibliometric study on scientific productivity in the use of smart bracelets.

In recent years, wearable sensors and mHealth applications are becoming an important part for recording and monitoring health parameters. The aim is to characterize bibli-ometric indicators on scientific productivity in the use of smart bracelets according to scientific journal, study topic and publication trend. A bibliometric study was per-formed. The data extracted from the articles were: year of publication, name of the journal, language of publication, country, type of study and subject matter. A total of 45 studies were identified (21 cross-sectional and 24 experimental), of which 43 were published in English, one in Spanish and one in German. A total of 32 scientific journals published eight research topics related to smartwatch use [active living with 17 studies (37.8%), followed by stress and anxiety with 7 studies (15.6%), nanogenerators (batteries) with 6 studies (13.3%), computing with 5 studies (11.1%), chronic diseases 4 studies (8.9%), COVID propagation 3 studies (6.7%), energy expenditure 2 studies (4.4%) and occupational health 1 study (2.2%)]. The journal Sensors (Basel) published the most articles in the last 6 years (n=7, 16%). The scientific productivity of both study types reflects a positive trend (cross-sectional studies R2= 0.82 and in experimental studies R2= 0.76). A total of 45 cross-sectional and experimental studies using smart-watches were verified in eight different study topics. The most investigated category was active living and the journal that published the highest number of articles was the journal Sensors (Basel).

Comparison of happiness in students of a public and private university in Peru.

BACKGROUND: Happiness is a positive component of mental well-being. In young university students, it is linked to ideals in many areas, such as physical health, mental health, harmonious inter-personal relationships, academic performance, and professional success. The aim of the study was to compare the happiness of university students from a state and private university according to professional areas and age range. MATERIALS AND METHODS: A descriptive cross-sectional study with selected 312 university students was conducted. The age range was from 17 to 32 years. The two professional areas surveyed were health sciences and engineering. Happiness was measured using a scale with 11 questions and four dimensions [1: Positive sense of life (three questions), 2: Satisfaction with life (three questions), 3: Personal fulfilment (two questions), and 4: Joy of living (three questions)]. The normality of the data was verified. Differences between sexes, areas, universities and ages were verified by t-test for independent samples. Differences between age ranges were verified by Anova. RESULTS: This study showed that there were no differences in happiness between EU and UP students when compared by gender, professional area, and age ranges. CONCLUSIONS: These results suggest that during the period of university studies, happiness values remain stable in both types of universities.

Body surface area is a predictor of maturity status in school children and adolescents.

BACKGROUND: Generally, Body surface area (BSA) changes significantly during growth and maturation. These increases portend a possible relationship between body size as determined by BSA with maturational status in children and adolescents. OBJECTIVE: To determine the relationship between maturity status (MS) obtained by non-invasive anthropometric methods and body surface area (BSA) in children and adolescents of both sexes in a regional population of Chile. Additionally, we sought to verify the type of linear or nonlinear relationship between MS and BSA in both sexes. METHODS: A descriptive (cross-sectional) study was designed in 950 children and adolescents of both sexes (539 males and 411 females). The age range ranged from 6.0 to 17.9 years. Anthropometric measurements were evaluated: body weight, standing height, sitting height. MS was assessed by means of two non-invasive anthropometric techniques. Both techniques predict peak years of growth velocity (APHV) through a regression equation for each sex. BSA (m2) was estimated by means of the Haycock equation. RESULTS: The R2 in the linear model is relatively lower (R2 = 0.80 to 0.89 in males and 0.74 to 0.66 in females) in relation to the nonlinear quadratic model (R2 = 0.81 in males and 0.76 to 0.69). The quadratic nonlinear quadratic model reflected an adequate fit (RMSE) for the data set, being in men (RMSE = 1.080 and 1.125), while in women (RMSE = 1.779 and 1.479). CONCLUSION: BSA is positively associated with MS determined by two non-invasive methods in Chilean children and adolescents: The nonlinear quadratic model was a better fit to the data distribution. The results suggest the use of BSA as a possible predictor of maturity status in Chilean youth.

Quantification of the Number of Steps in a School Recess by Means of Smart Bands: Proposal of Referential Values for Children and Adolescents.

(1) Background: Regular physical activity has multiple benefits. Therefore, school recess is a key tool to provide opportunities for schoolchildren to engage in extracurricular physical activity, have fun, play and interact with their peers. The aim is to provide reference data to quantify the number of steps that children and adolescents perform in a school recess using smart bands according to age range and sex. (2) Method: A descriptive cross-sectional study was carried out in 494 schoolchildren aged 6 to 17 years (292 males and 202 females). Weight, standing height and waist circumference (WC) were evaluated. The body mass index (BMI) was calculated. The quantification of the number of steps during school recess was performed using a smart band. (3) Results: Percentiles were constructed for the number of steps (number of steps/recess). The cut-off points considered were p75 (above average). The median values in both sexes decreased as the age range increased. Youth who walked fewer steps during recess (

Functional fitness and fall risk in older adults practitioners or non-practitioners of Tai Chi.

Tai chi is a fundamental tool that has a significant influence on balance, motor function and fear of falling among older adults. The objective of the study was to verify functional fitness and fall risk in older adults (OA) practitioners and non-practitioners of Tai Chi. An ex-post-facto study was carried out in practicing and non-practicing OA of Tai chi. The sample selection was non-probabilistic (convenience). Thirty-one adults with an age range of 65 to 80 years were studied. Two study groups were formed: Group practicing Tai Chi [GPT (n= 15 subjects)] and Group not practicing Tai Chi [GNPT (n= 16 subjects)]. Age, weight, height, waist circumference were assessed. Body mass index (BMI) and fat mass (FM) were calculated. Five functional fitness tests were assessed: biceps curl (30sec), Chair stand (30sec), agility (sec), 2min walk (#rep) and 6min-1 walk (m). Fall risk was measured using a 13-item scale. The GPT showed better performance in all five functional fitness tests (biceps curl, Chair stand, agility, 2min gait and 6min walk) compared to the GPT. The effect size (ES: ~0.20 to 0.48) and Cohen's d (~ 0.39 to 1.10) between both groups were medium to large. There were also differences between the mean values in fall risk between both groups (GNPT: 2.1±1.7points and GNPT: 4.7±1.9points, p<0.05). This study demonstrated that the group of OA practicing Tai Chi presented better levels of functional fitness and less risk of falling in relation to their counterparts who did not practice Tai Chi. These results suggest including this type of old-time exercise in physical activity programs that promote functional fitness wellness and fall prevention among OA.

Systematic review of the anthropometric profile of female futsal players 2010-2020.

The objective was to summarize the scientific literature on the anthropometric characteristics of female futsal players. A systematic review documentary study was carried out. SCOPUS, PUBMED and SCIELO databases were used to search for information on primary studies related to the anthropometric profile of women's indoor soccer (elite and non-elite). The keywords used were: futsal, female, anthropometry. The range of years for the search was from 2010 to 2020. To analyze anthropometric differences, two groups were formed: group A: elite and group B: non-elite. 31 primary studies were identified, 22 (71%) in Scopus, 5 (16.1%) in PUBMED and 4 (12.9%) in SCIELO. Three publication languages were considered (English, Spanish and Portuguese) and 6 countries were identified (Brazil, Spain, Iran, Turkey, Venezuela and Italy). Players in the elite group evidenced higher weight, height, and BMI relative to their non-elite counterparts. Discrepancy in anthropometric characteristics between elite and non-elite players was verified. These results suggest that in order to participate in competitions at the highest level in women's futsal, they should have greater weight, height and BMI than their non-elite counterparts.

Accuracy in body composition scanning by adult half-body DXA scanning.

Introduction: Introduction: dual-energy X-ray absorptiometry (DXA) is the gold standard method, although one limitation is the size of the scan area. Objective: the objective was to verify the accuracy of body composition (BC) scanning through half-body DXA scanning compared to standard total body scanning. Methods: a study was conducted on 145 volunteers. Weight and height were assessed. Body mass index (BMI) was calculated. DXA was used for whole-body scan (WBS) and half-body scan (HBS). WBS was used as the reference method and the following indicators were extracted: bone mineral content (BMC), fat mass (FM), lean soft tissue (LST) and percentage fat mass (%FM). Results: no differences were observed in the body composition indicators (BMC, FM, LST and %FM) when compared between the reference WBS scanner and the HBS scanner. The predictive power between both scans ranged in both sexes between R2 = 0.94 and 0.98. The DRI desirable reproducibility index values defining the degree of agreement between both scans ranged from 0.97 to 0.99, and the values for precision (0.97 to 0.99) and accuracy (0.99) were high. Conclusion: HBS scanning by DXA evidenced agreement, and high values of accuracy and precision to assess body composition indicators (BMC, FM, LST and %FM).

Introducción: Introducción: la absorciometría de rayos X de doble energía (DXA) es el método de referencia, aunque una limitación es el tamaño del área de exploración. Objetivo: el objetivo fue verificar la precisión de la exploración de la CB mediante la exploración DXA de medio cuerpo en comparación con la exploración estándar de todo el cuerpo. Métodos: se realizó un estudio con 145 voluntarios. Se evaluaron el peso y la altura. Se calculó el índice de masa corporal (IMC). Se utilizó la DXA para la exploración de cuerpo entero (WBS) y la exploración de medio cuerpo (HBS). Se utilizó la PEP como método de referencia y se extrajeron los siguientes indicadores: contenido mineral óseo (CMO), masa grasa (MG), tejido blando magro (TBL) y porcentaje de masa grasa (%MG). Resultados: No se observaron diferencias en los indicadores de composición corporal (BMC, FM, LST y %FM) cuando se compararon entre el escáner WBS de referencia y el escáner HBS. El poder predictivo entre ambos escáneres osciló en ambos sexos entre R2 = 0,94 y 0,98. Los valores del índice de reproducibilidad deseable DRI que definen el grado de acuerdo entre ambas exploraciones oscilaron entre 0,97 y 0,99, y los valores de precisión (0,97 a 0,99) y exactitud (0,99) fueron altos. Conclusión: la exploración de HBS mediante DXA evidenció concordancia y altos valores de exactitud y precisión para evaluar los indicadores de composición corporal (BMC, FM, LST y %FM).

Fat-free mass and maturity status are determinants of physical fitness performance in schoolchildren and adolescents

Abstract Objectives: The objective of the study was to verify whether (FFM), maturity status (MS) and chronological age (CA) are determinants of physical fitness performance, and to analyze FFM and physical performance aligned by CA and MS in children and adolescents. Methods: A descriptive correlational study was carried out in 863 schoolchildren. Weight, height, and waist circumference (WC) were evaluated. Body mass index (BMI), FFM, fat mass (FM), MS (Age at peak height velocity, APHV) were calculated. The physical tests of velocity 20 m, agility 5 m × 10rep, and horizontal jump (HJ) were evaluated. Results: The APHV was estimated in boys at 14.0 ± 0.36APHV and in girls at 11.96 ± 0.49APHV. The relationships between CA and APHV with FFM was r = 0.80 in boys and r = 0.44 to 0.45 in girls. The relationships between FFM and physical tests in boys were [HJ (r = 0.70), agility 5m × 10rep (r = -0.68), velocity (r = -0.61)] and in girls [HJ (r = 0.42), agility 5m × 10rep (r = -0.52), velocity (r = -0.20)]. The differences in FFM and physical fitness tests were more pronounced when aligned by APHV than by CA. Conclusion: It was verified that both FFM, CA, and APHV are determinants of physical fitness performance. In addition, the APHV should be introduced in physical education as a means of ranking physical performance among schoolchildren.