Relationship between age and handgrip strength: Proposal of reference values from infancy to senescence.

Introduction: Measurement of hand grip strength (HGS) has been proposed as a key component of frailty and has also been suggested as a central biomarker of healthy aging and a powerful predictor of future morbidity and mortality.

Objectives: (a) To determine whether a nonlinear relationship model could improve the prediction of handgrip strength (HGS) compared to the linear model and (b) to propose percentiles to evaluate HGS according to age and sex for a regional population of Chile from infancy to senescence.

Methods: A cross-sectional descriptive study was developed in a representative sample of the Maule region (Chile).

Comparison of anthropometric indicators as predictors of the percentage of fat mass in young people and older adults in Chile.

Objective: To verify whether triponderal mass index (TMI) has a greater accuracy than body mass index (BMI), waist circumference (WC) and waist-to-height ratio (WHtR) as predictors of obesity in young people and older adults in a region of Chile.

Material And Methods: A cross-sectional descriptive study was carried out in 1176 adults (565 men and 611 women) from the Maule region (Chile). Their ages ranged from 20 to 80 years.

Relationship between muscular fitness and bone health in young baseball players.

The physical actions developed by baseball players can increase muscular fitness, and consequently improve bone health. The objective was to relate some indicators of muscular fitness to bone health in young baseball players. A descriptive cross-sectional study was carried out in 102 children and adolescent baseball players of the Brazilian National Team.

Assessment of sleep disorders and proposed percentiles for adolescents.

Objectives: The objectives of this study included: a) to develop a valid and reliable self-reporting instrument to assess sleep disorders among Chilean adolescent students and b) to develop percentiles for age and sex.

Methodology: This was a descriptive, crosssectional study in 2310 adolescent students conducted in the Maule Region, Chile. The sleep disorder self-report was developed considering five categories: duration, alterations, breathing problems, fatigue, and stimulant use.

Tracking of physical fitness in elementary school children: The role of changes in body fat.

Objectives: The aim of the present study was to examine the stability of physical fitness, and the interrelationships among intra-individual changes in fitness and fatness among elementary school children.

Methods: A longitudinal study was conducted among 372 adolescents (196 boys) and followed up over 3 years (from childhood to adolescence). Physical fitness was estimated using three indicators: cardiorespiratory fitness (through a 9-minute running test), flexibility (through a sit-and-reach test), and muscle resistance (through maximal abdominals in 1 minute).

Normative data for handgrip strength in children and adolescents in the Maule Region, Chile: Evaluation based on chronological and biological age.

Background: Hand grip strength (HGS) is associated with a number of causes resulting in cardiovascular death, in addition to bone fragility, and the presence of sarcopenia. The goal of our study was to analyze HGS of students based on chronological and biological age and propose normative standards for children and adolescents from Chile.

Methods: We studied 4604 school children of both sexes between the ages of 6.

Body mass index and physical fitness in Brazilian adolescents.

Objective: Evaluate the relationship between body mass index and physical fitness in a cross-sectional sample of Brazilian youth.

Methods: Participants were 3849 adolescents (2027 girls) aged 10-17 years. Weight and height were measured; body mass index was calculated.

Weight, height and body mass index of children and adolescents living at moderate altitude in Colombia.

Introduction: There is increasing concern over the study of physical growth in different regions of the world, although altitude is not considered an adjustment factor.

Objectives: Compare physical growth variables and body mass index (BMI) patterns with the Centers for Disease Control and Prevention (CDC) 2012 reference data and develop percentiles for children and adolescents.

Methodology: School children living at moderate altitude in Bogotá (Colombia) were studied.

Hand grip strength and maximum peak expiratory flow: determinants of bone mineral density of adolescent students.

Background: Maintaining and building healthy bones during the lifetime requires a complicated interaction between a number of physiological and lifestyle factors. Our goal of this study was to analyze the association between hand grip strength and the maximum peak expiratory flow with bone mineral density and content in adolescent students.

Methods: The research team studied 1427 adolescent students of both sexes (750 males and 677 females) between the ages of 11.

Reference standards to assess physical fitness of children and adolescents of Brazil: an approach to the students of the Lake Itaipú region-Brazil.

Background: The importance of assessing body fat variables and physical fitness tests plays an important role in monitoring the level of activity and physical fitness of the general population. The objective of this study was to develop reference norms to evaluate the physical fitness aptitudes of children and adolescents based on age and sex from the lake region of Itaipú, Brazil.

Methods: A descriptive cross-sectional study was carried out with 5,962 students (2,938 males and 3,024 females) with an age range of 6.

Development of equations and proposed reference values to estimate body fat mass among Chilean children and adolescents.

Introduction: The assessment of body composition is relevant to establish nutritional status and identify potential health risks.

Objetive: a) To develop regression equations to predict fat mass (FM) using a dual-energy X-ray absorptiometry as reference method; b) to propose reference FM values based on chronological and biological age for Chilean children and adolescents.

Methodology: Cross-sectional study in children and adolescents aged 5.

Proposed equations and reference values for calculating bone health in children and adolescent based on age and sex.

Background: The Dual Energy X-Ray Absorptiometry (DXA) is the gold standard for measuring BMD and bone mineral content (BMC). In general, DXA is ideal for pediatric use. However, the development of specific standards for particular geographic regions limits its use and application for certain socio-cultural contexts.

Linear and nonlinear relationships between body mass index and physical fitness in Brazilian children and adolescents.

Objectives: The purpose of this study was to evaluate the linear and curvilinear relationship between body mass index (BMI) and physical fitness in children and adolescents.

Methods: Participants were 4567 (2505 girls) children aged 6-16 years. Weight and height were measured and BMI was calculated and adjusted for age and sex using WHO z-scores.

Secular trends of physical growth and abdominal adiposity of school children and adolescents living at a moderate altitude in Peru.

Objective: Identify changes in physical growth and abdominal adiposity at an interval of 14 years in children and adolescents living at a moderate altitude in Peru.

Materials And Methods: The data comes from two cross-sectional studies carried out in the city of Arequipa, Peru, located at a moderate altitude of 2,320 meters. In 2001, 473 males and 482 females were assessed, and in 2015, 432 males and 403 females between 6.

Accuracy of Body Mass Index Cutoffs for Classifying Obesity in Chilean Children and Adolescents.

Objective: To determine the accuracy of two international Body Mass Index (BMI) cut-offs for classifying obesity compared to the percentage of fat mass (%FM) assessed by Dual-Energy X-ray Absorptiometry (DXA) in a Chilean sample of children and adolescents;

Material And Methods: The subjects studied included 280 children and adolescents (125 girls and 155 boys) aged 8 to 17 years. Weight and height were measured. The BMI was calculated.

Improving Sprint Performance in Soccer: Effectiveness of Jump Squat and Olympic Push Press Exercises.

Training at the optimum power load (OPL) is an effective way to improve neuromuscular abilities of highly trained athletes. The purpose of this study was to test the effects of training using the jump squat (JS) or Olympic push-press (OPP) exercises at the OPL during a short-term preseason on speed-power related abilities in high-level under-20 soccer players. The players were divided into two training groups: JS group (JSG) and OPP group (OPPG).

Physical Growth, Biological Age, and Nutritional Transitions of Adolescents Living at Moderate Altitudes in Peru.

Background: Peru is experiencing a stage of nutritional transition where the principal characteristics are typical of countries undergoing development.

Objectives: The objectives of this study were the following: (a) compare physical growth patterns with an international standard; (b) determine biological age; and (c) analyze the double nutritional burden of adolescents living at a moderate altitude in Peru.

Design: Weight, standing height, and sitting height were measured in 551 adolescents of both sexes (12.

Association between health-related physical fitness and body mass index status in children.

The purpose of this study was to investigate the association between body mass index (BMI) status and physical performance in Brazilian children. The analyzed sample was composed of 978 children of both sexes (518 boys and 460 girls), aged 7 to 11 years. BMI and skinfolds were measured, and three motor tests were applied (flexibility, cardiorespiratory fitness, and muscular strength/endurance).

[Reliability of a questionnaire to assess physical activity in normal weight adolescents and overweight].

Introduction: In recent years it has reported high levels of obesity associated with low levels of physical activity, which shows the need for assessment as elements of health and quality of life.

Objective: To verify the ability of reproducibility of a PA questionnaire in school adolescents classified as normal weight, overweight and obese.

Material And Methods: A descriptive cross-sectional study was conducted in 1306 adolescent students (562 men and 744 women) from three municipal educational institutions of the province of Talca (Chile).

Referencial values for the physical growth of school children and adolescents in Campinas, Brazil.

Aims: To compare the values of weight, height and IMC with the regional curve (Cariri); to compare with the international references of the CDC-2000; and to construct references that will measure physical growth from childhood to adolescence.

Subjects And Methods: The sample consists of 6531 individuals with an age range of 6.0-17.

Nutritional status and blood pressure in adolescent students.

Introduction: Obesity is the main risk factor for arterial hypertension andis associatedwitha higher morbidity, both in the short and long term.

Objectives: To compare anthropometric and blood pressure indicators in terms of the nutritional status, to verify the relationship between nutritional status and blood pressure, and to establish the prevalence of hypertension in terms of the nutritional status in both male and female adolescents.

Methods: Cross-sectional, descriptive study on 499 adolescent students aged 11-15 years old.

[Reference curves for assessing the physical growth of male Wistar rats].

Introduction: Wistar rats are one of the most popular strains routinely used for research in the laboratory to serve as an important research tool, so it requires strict control of variables such as age, sex and body weight, and Thus to extrapolate the results to the human model.

Objective: To develop reference curves for assessing the physical growth of male Wistar rats according to chronological age and somatic maturation from a non-invasive.

Methodology: The subjects studied were 731 male Wistar rats transversely.

Salivary IgA response and upper respiratory tract infection symptoms during a 21-week competitive season in young soccer players.

Sports training and competition are significant sources of stress, especially for young athletes. It is well known that physiological and psychological stressors induce neuroendocrine responses that could modulate immune system function. However, to date, little is known about the immune responses of young soccer players during a competitive season.