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.

Has COVID-19 lowered physical activity practice while boosting online searches for professional exercise information?

COVID-19 is an infectious and contagious disease, caused by the SARS-CoV-2 virus. Due to the rapid spreading of the virus and its lethal consequences, the WHO declared a pandemic. One of the main strategies to treat and prevent the spreading was the stay home safe, a social isolation situation that was accompanied by the closing of fitness gyms, city parks and facilities proper to exercise. This context promoted an increase in home fitness programs and in the search for information online regarding exercise and health. So, the objective of this study was to understand the effects of the pandemic on physical activity behavior and online information search regarding exercise programs. Data collection was through a google forms questionnaire, all procedures were approved by the University ethics committee and we collected data from 1065 participants. Our results showed that the participants main behavior was maintained, 80.7% of our sample were active before the pandemic and only 9.7% of this group stopped being active. On the other hand we registered 7% of participants that started exercise after the pandemic installation. Information about exercise was searched outside social media by 49.6% of the participants with 32.5% using social media. 56.1% would look only for professional advice, interestingly 11.4% of the participants were active without any kind of advice. We concluded that Covid-19 pandemic installation affected negatively the population physical activity behavior and increased awareness about the importance of exercise as a health strategy.

Encouraging physical fitness in Brazilian adolescents with excess weight: can they outperform their eutrophic peers in some activities?

BACKGROUND: There is the need to encourage physical activity (PA) among adolescents with overweight or obesity. OBJECTIVES: The present study aimed to assess the relationship between health-related physical fitness (PF) and nutritional status, and to identify those activities more suited to adolescents with excess weight. METHODS: This cross-sectional study included 3,062 in-school adolescents, aged 10-18 years. We collected information on sex, age, weight, height, skinfold thickness, trunk height and leg length, and calculated body mass index (BMI) z-score, fat mass percentage, and peak height velocity (PHV). Participants were tested for PF by the 20-m shuttle run test (cardiorespiratory fitness); medicine ball throw and standing long jump tests (musculoskeletal fitness) and sit and reach test (flexibility). We used generalized linear mixed models (GLMM) to analyze the relationship between nutritional status and performance in the fitness tests, controlled for maturity offset and fat mass percentage. RESULTS: 1,563 (51%) were boys, mean age 12.6 years (±1.8), 22.8% were overweight and 12.5% had obesity. In both sexes, adolescents with obesity did better in the upper body strength test than their eutrophic peers. Boys with obesity had worse cardiorespiratory fitness and lower body muscular strength than eutrophic boys. Girls with obesity had similar cardiorespiratory fitness and better lower body strength than eutrophic girls. CONCLUSION: In muscular strength fitness tests, adolescents with obesity performed similarly to, or better than, their eutrophic peers. Motivation to maintain regular PA is reinforced by positive experiences. Interventions that emphasize muscular strength PF should be developed for adolescents with obesity.

Reference values of the body composition of young chilean soccer players / Valores de referencia de la composición corporal de jóvenes futbolistas chilenos / Valores de referência da composição corporal de jovens futebolistas chilenos

ABSTRACT Objective: To analyze whether fat mass (FM) and fat-free mass (FFM) should be evaluated by chronological age and/or biological age and propose curves to classify the body composition of young Chilean soccer players. Methods: A cross-sectional descriptive study was developed. Six hundred and forty-two soccer players between 13.0 and 18.9 years of age were recruited. Body mass, height, trunk-cephalic height, and tricipital and subscapular skinfolds were evaluated. Biological maturation was determined using peak height velocity age (PHV) and the percentage of fat mass was estimated by regression equations. The reference percentiles were calculated using the LMS method. Results: The values of R2 were lower for chronological age (FM = 0.07% and FFM = 0.13%) than for biological age (FM = 0.31% and FFM = 0.50%). Eleven percentiles (p3, p5, p10, p15, p25, p50, p75, p85, p90, p95 and p97) were calculated for FFM and FM. Conclusion: Biological age (PHV) is a better predictor of FFM and FM than chronological age. The references proposed can be used to monitor the body composition of young Chilean soccer players. Level of Evidence II; Diagnostic Study .

Resumen Objetivo: Analizar si la masa grasa (MG) y la masa libre de grasa (MLG) deben ser evaluadas por la edad cronológica y/o por la edad biológica, y proponer curvas para clasificar la composición corporal de jóvenes futbolistas chilenos. Métodos: Se elaboró un estudio descriptivo transversal. Fueron reclutados 642 futbolistas entre 13,0 y 18,9 años. Fueron medidas masa corporal, estatura, altura tronco-cefálica, pliegues cutáneos tricipital y subescapular. La madurez biológica fue determinada por la edad de pico de velocidad de crecimiento (EPVC) y el porcentual de masa grasa fue estimado por ecuaciones de regresión. Los percentiles de referencia fueron calculados por el método LMS. Resultados: Los valores de R2 para edad cronológica fueron menores (MG=0,07% y MLG=0,13%) en comparación con los valores para la edad biológica (MG=0,31% y MLG=0,50%). Fueron calculados 11 percentiles (p3, p5, p10, p15, p25, p50, p75, p85, p90, p95 y p97) para la MLG y MG. Conclusión: La edad biológica (EPVC) es un predictor mejor de la MLG y de la MG que la edad cronológica. Las referencias propuestas pueden servir para monitorizar la composición corporal de jóvenes futbolistas chilenos. Nivel de evidencia II; Estudio de diagnóstico .

RESUMO Objetivo: Analisar se a massa gorda (MG) e a massa livre de gordura (MLG) devem ser avaliadas pela idade cronológica e/ou pela idade biológica, e propor curvas para classificar a composição corporal de jovens futebolistas chilenos. Métodos: Elaborou-se um estudo descritivo transversal. Foram recrutados 642 futebolistas entre 13,0 e 18,9 anos. Massa corporal, estatura, altura tronco-cefálica, dobras cutâneas tricipital e subescapular foram medidas. A maturação biológica foi determinada pela idade de pico de velocidade de crescimento (IPVC) e o percentual de massa gorda foi estimado por equações de regressão. Os percentis de referência foram calculados pelo método LMS. Resultados: Os valores de R2para idade cronológica foram menores (MG = 0,07% e MLG=0,13%) em comparação com os valores para a idade biológica (MG = 0,31% e MLG = 0,50%). Foram calculados 11 percentis (p3, p5, p10, p15, p25, p50, p75, p85, p90, p95 e p97) para a MLG e MG. Conclusão: A idade biológica (IPVC) é um preditor melhor da MLG e da MG do que a idade cronológica. As referências propostas podem servir para monitorar a composição corporal de jovens futebolistas chilenos. Nível de evidência II; Estudo de diagnóstico .

Aerobic capacity of chilean adults and elderly: proposal of classification by regional percentiles / Capacidade aeróbia de adultos e idosos chilenos: proposta de classificação por percentis regionais / Capacidad aeróbica de adultos y ancianos chilenos: propuesta de clasificación por percentiles regionales

ABSTRACT Introduction Aerobic fitness is an important predictor that contributes to the preservation of functional independence during the aging process. Its measurement represents a fundamental tool in the identification of multiple health problems. Objective To compare the aerobic capacity of adults and elderly subjects through international studies and to develop percentiles by age group using the LMS method. Methods A cross-sectional descriptive study was conducted with 1146 subjects (437 men and 709 women). The age group of the sample ranged from 50 to 84 years. The subjects evaluated came from the physical activity programs offered by the National Sports Institute (IND) and by the city council of Talca (Chile). Body mass, stature, oxygen saturation (SatO2), six-minute walk test, and systolic and diastolic blood pressure were assessed. Body Mass Index (BMI) was calculated for both sexes. The LMS method was used to propose the percent distribution. Results Aerobic capacity decreases with age (28.5% for men and 29.9% for women). There was a negative relationship between age and the six-minute walk test (men r = -0.13 and women r = -0.39). There was a discrepancy between the elderly subjects in the current study and those from international studies. The normative data for the classification of aerobic fitness were expressed in percentiles (p3, p5, p10, p15, p25, p50, p75, p85, p90, p95 and p97). Conclusion The aerobic performance of elderly subjects diminishes as they age; in addition, the current results differ from international studies, which motivated the development of percentiles to classify aerobic fitness in everyday situations, especially in places with few resources and particularly where field tests are considered a priority for large-scale physical evaluation. Level of evidence II; Diagnostic studies - investigation of diagnostic test.

RESUMO Introdução A aptidão aeróbia é importante preditor que contribui com a preservação da independência funcional à medida que se envelhece. Sua mensuração transforma-se em ferramenta fundamental na identificação de múltiplos problemas de saúde. Objetivo Comparar a capacidade aeróbia de adultos e idosos com estudos internacionais e desenvolver percentis por faixas etárias, utilizando o método LMS. Métodos Elaborou-se um estudo descritivo transversal com 1.146 sujeitos (437 homens e 709 mulheres). A faixa etária da amostra variou de 50 a 84 anos. Os sujeitos avaliados eram oriundos dos programas de atividade física oferecidos pelo Instituto Nacional de Desporto (IND) e pela prefeitura de Talca (Chile). Avaliaram-se massa corporal, estatura, saturação de oxigênio (SatO2), teste de caminhada de 6 minutos e pressão arterial diastólica e sistólica. Calculou-se o índice de massa corporal (IMC) para ambos os sexos. Utilizou-se o método LMS para propor a distribuição percentílica. Resultados A capacidade aeróbia diminui com o decorrer da idade (28,5% para os homens e 29,9% para as mulheres). Houve relação negativa entre a idade e o teste de caminhada de 6 minutos (homens: r = -0,13; mulheres: r = -0,39). Observou-se discrepância entre os idosos do presente estudo com os de estudos internacionais. Os dados normativos para a classificação da aptidão aeróbia foram expressos em percentis (p3, p5, p10, p15, p25, p50, p75, p85, p90, p95 y p97). Conclusão Os idosos diminuem o desempenho aeróbio conforme a idade avança. Os presentes resultados diferem dos estudos internacionais, o que motivou o desenvolvimento dos percentis para classificar a aptidão aeróbia em situações cotidianas, especialmente em locais com poucos recursos e principalmente onde os testes de campo são considerados prioritários para avaliação física em larga escala. Nível de evidência II; Estudos diagnóstico - investigação de teste diagnóstico.

RESUMEN Introducción La aptitud aeróbica es un importante predictor que contribuye con la preservación de la independencia funcional a medida que se envejece. Su medición se transforma en una herramienta fundamental en la identificación de múltiples problemas de salud. Objetivo Comparar la capacidad aeróbica de adultos y ancianos con estudios internacionales y desarrollar percentiles por grupos de edad utilizando el método LMS. Métodos Se elaboró un estudio descriptivo transversal con 1146 sujetos (437 hombres y 709 mujeres). El grupo de edad de la muestra varió de 50 a 84 años. Los sujetos evaluados eran oriundos de los programas de actividad física ofrecidos por el Instituto Nacional de Deporte (IND) y por la Municipalidad de Talca (Chile). Se evaluaron masa corporal, estatura, saturación de oxígeno (SatO2), test de seis minutos de caminata y presión arterial diastólica y sistólica. Se calculó el índice de masa corporal (IMC) para ambos sexos. Se usó el método LMS para proponer la distribución de percentil. Resultados La capacidad aeróbica disminuye con el transcurso de la edad (28,5% para los hombres y 29,9% para las mujeres). Hubo relación negativa entre la edad y el test de caminata de seis minutos (hombres r= -0,13 y mujeres r= -0,39). Se observó discrepancia entre los ancianos del presente estudio con los de estudios internacionales. Los datos normativos para la clasificación de la aptitud aeróbica fueron expresados en percentiles (p3, p5, p10, p15, p25, p50, p75, p85, p90, p95 y p97). Conclusión Los ancianos disminuyen el rendimiento aeróbico conforme avanza la edad. Los presentes resultados difieren de los estudios internacionales, lo que motivó el desarrollo de los percentiles para clasificar la aptitud aeróbica en situaciones cotidianas, especialmente en locales con pocos recursos y principalmente donde los tests de campo son considerados prioritarios para la evaluación física a larga escala. Nivel de Evidencia II; Estudios diagnóstico-investigación de test diagnóstico.

C-Reactive Protein Serum Levels as an Internal Load Indicator of Sprints in Competitive Football Matches.

This study compared internal load variable dynamics across three consecutive football matches and investigated its relationship with the number of sprints performed by players. Twenty-three male players had blood and salivary samples collected for hormonal concentration (testosterone, cortisol, and testosterone-cortisol ratio), and serum analysis (interleukin-6, interleukin-1-beta, and c-reactive-protein), respectively. Sprints were measured through Global Position System devices. Testosterone and testosterone-cortisol-ratio presented a decreasing behavior up to the second match, and all other indicators presented an increasing behavior during the same period, c-reactive-protein was the only indicator observed to significantly rise up to the third match as well (0.38±0.02 mg/L; 0.49±0.05 mg/L; 0.69±0.05 mg/L; 0.89±0.08 mg/L). C-reactive-protein showed strong correlations with sprints in the second and third matches (p<0.01, r=0.71 and 0.79), and weak-to-moderate in the first one (p<0.05, r=0.59). Interleukin-6 and interleukin-1-beta presented weak-to-moderate correlation in every match (p<0.05, r=0.48 to 0.51; r=0.51 to 0.55) while testosterone-cortisol ratio presented weak-to-moderate correlation only in the third one (p<0.05, r=0.42). Multilevel linear regression showed that c-reactive-protein had a higher R2 than other biomarker in any regression model (R2=0.624; p<0.001). Therefore, c-reactive-protein can be a valid and reliable indicator of sprinting in competitive football. Future research should explore longer periods of monitoring and/or others external load variables so that other behaviors may arise to knowledge.