Can the body mass index influence the skin temperature of adolescents assessed by infrared thermography?

Infrared thermography (IRT) is a technology that has been used as an auxiliary tool in the diagnostic process of several diseases and in sports monitoring to prevent injuries. However, the evaluation of a thermogram can be influenced by several factors that need to be understood and controlled to avoid a misinterpretation of the thermogram and, consequently, an inappropriate clinical action. Among the possible factors that can affect IRT are anthropometric factors, especially those related to body composition. Based on these, our objective was to verify the influence of Body Mass Index (BMI) on skin temperature (Tsk) in male adolescents. One hundred male adolescents (age: 16.83 ±â€¯1.08 years; body mass: 66.51 ±â€¯13.35 kg; height: 1.75 ±â€¯7.04 m and BMI: 21.57 ±â€¯4.06 kg/m2) were evaluated and divided into three groups, based on the World Health Organization (WHO) proposed classification ranges: underweight (n = 33), normal weight (n = 34) and overweight/obesity (n = 34). Thermograms were obtained using the FLIR T420 thermal imager after a period of acclimatization of the subjects in a controlled environment (temperature: 21.3 ±â€¯0.7 °C and humidity: 55.3 ±â€¯2.2%); they were evaluated using the ThermoHuman® software, integrating the original regions of interest (ROI) into seven larger ROIs. The results showed that underweight individuals had higher Tsk values than normal weight and overweight/obese individuals for all evaluated ROIs, and overweight/obese individuals had lower Tsk values than normal weight individuals for most evaluated ROIs, except for arms region. BMI showed a correlation of -0.68 and -0.64 for the anterior and posterior regions of the trunk, respectively. Thermal normality tables were proposed for various ROIs according to BMI classification. Our study demonstrated that BMI can affect the Tsk values assessed by IRT and needs to be considered to interpret the thermograms.

Cardiorespiratory Fitness and Physical Activity among Children and Adolescents: 3-Year Longitudinal Study in Brazil.

The aim of this study was to investigate the effect of physical activity (PA) levels over 36 months on the cardiorespiratory fitness (CRF) of children and adolescents. This was a longitudinal study carried out from 2016 to 2019 with 127 children and adolescents (82 males and 45 females) aged 13.5 ± 1.2 years at baseline. The 20 m shuttle run test (20 mSRT) was used to predict CRF. The questionnaires PAQ-C and PAQ-A were used to investigate PA. The 2 × 4 repeated measures ANCOVA was used, and the significance level was p ≤ 0.05. There was a linear trend in the interaction between level of PA and CRF throughout the 36-month study period in both sexes (males-distance covered: F1.78 = 4.567; p = 0.04; VO2max: F1.78 = 5.323; p = 0.02; females-distance covered: F1.41 = 6.989; p = 0.01; VO2max: F1.41 = 6.585; p = 0.01). Physically active males showed a gradual increase in CRF throughout the analyzed period. For females, CRF remained constant in the first 24 months, showing a slight increase only after 36 months in physically active ones. The findings of this study reinforce the importance of PA throughout childhood and adolescence to improve CRF.

Validity of the Body Adiposity Index in Predicting Body Fat in Adults: A Systematic Review.

The Body Adiposity Index (BAI) is a practical anthropometric method used to measure body fat (BF) percentage (BF%). Recently developed, the validity and precision of BAI has been studied with adult samples of men and women, populations from different countries and ethnicities, varying amounts of BF, and sensitivity to detecting change over time. However, it is still necessary to determine its potential use in clinical practice and epidemiologic studies. Thus, our objective was to verify, through a systematic review, the validity of the BAI in predicting BF% in adults. Two independent researchers performed a search using PubMed, Web of Science, Science Direct, and Scopus databases. In order to be included, the studies had to use dual-energy X-ray absorptiometry (DXA) as a reference method. We excluded studies with samples from individuals with diseases or syndromes that alter the regional distribution of BF%. We included 19 studies with samples on individuals from different continents, varied ethnicities, both sexes, and a wide age range (18-83 y). The concordance of the BAI with DXA assessed by Lin's concordance correlation coefficient showed results classified as poor (pc < 0.90). Bland-Altman plots showed that the BAI produced large individual errors when predicting BF% in all studies using this analysis. The studies were consistent in affirming that the BAI showed limited capacity to estimate BF% in adults. The BAI shows wide individual errors, in agreement with the reference method, and a lack of sensitivity in detecting change in BF% over time. The method presents a systematic error of BF% overestimation in individuals with ≤20% of BF, and underestimation in individuals with >30% of BF, regardless of sex, age, and ethnicity. The results of this systematic review show enough evidence that the BAI does not present satisfying results, and its use is not recommended for BF% determination in adults.

Can body mass index influence the skin temperature of adolescents? A preliminary study with the use of infrared thermography / O índice de massa corporal pode influenciar a temperatura da pele de adolescentes? Um estudo preliminar com o uso da termografia infravermelha

Abstract Infrared thermography (IRT) has been used to assess skin temperature (Tsk), especially during the COVID-19 pandemic, as an important tool in medical screening not only of the general population, but also of young athletes. However, the subcutaneous adipose tissue can act as an insulator when the Tsk is assessed by IRT, modifying the normal Tsk data and leading to their misinterpretation. Considering that the body mass index (BMI) is an important predictor of obesity, the objective of this study was to verify if the Tsk measured by IRT is affected by the BMI in adolescents. A preliminary study was carried out being four participants intentionally selected, all 16 years old, each one classified in a different BMI range according to the criteria of the World Health Organization for the adolescent population: underweight, healthy weight, overweight and obesity. Four thermograms of each participant were recorded and the ThermoHuman® software was used to evaluate 82 regions of interest (ROI), which were integrated into 6 body regions. Using healthy weight subjects as a reference, it was found a progressive reduction in Tsk in all ROI compared to overweight and obese participants, with emphasis on the anterior region of the trunk (3.04% and 6.69% less respectively), and an increase in the Tsk of all body regions for the underweight subject. There are indications that BMI can influence the Tsk value in adolescents and should be taken into account when analyzing thermograms for a correct evaluation of thermal normality.

Resumo A termografia infravermelha (TI) tem sido uma técnica empregada para avaliar a temperatura da pele (TP), especialmente durante a pandemia do COVID-19. Contudo, existem indicações que o tecido adiposo subcutâneo pode agir como uma camada isolante, alterando o comportamento da TP, o que pode dificultar a interpretação da normalidade térmica. Tendo em vista que o índice de massa corporal (IMC) é considerado um importante preditor de obesidade, o objetivo deste estudo foi verificar se a TP sofre interferência de diferentes classificações de IMC em adolescentes. Foram selecionados 4 participantes de maneira intencional, todos com 16 anos, cada um foi classificado em uma diferente faixa de IMC para população de adolescentes segundo a classificação proposta pela Organização Mundial de Saúde para essa idade: baixo peso, peso normal, sobrepeso e obesidade. Foram feitos quatro termogramas, avaliados no software ThermoHuman®, que avalia 82 regiões corporais de interesse (RCI), que foram integradas em 6 regiões corporais. Utilizando os indivíduos com peso normal como referência, foi encontrada uma redução progressiva na TP comparada aos participantes com sobrepeso e obesidade, com ênfase para a região anterior de tronco (3.04% e 6.69% menores, respectivamente), e um aumento na TP de todas as regiões corporais comparadas ao sujeito com baixo peso. Isso indica que o IMC pode influenciar nos valores da TP em adolescentes e deve ser levado em consideração para uma avaliação correta da normalidade térmica.

Effect of a school soccer competition with consecutive day games on the recovery status of U-19 players / Efeito de uma competição escolar de futebol com jogos em dias consecutivos no estado de recuperação de jogadores sub-19

Abstract The present study aimed to evaluate the effect of a school soccer competition with consecutive day games on the recovery status of U-19 players. Thirty-one school athletes (17.1±1.1 years) who played a U-19 school soccer competition (composed of two groups of four soccer teams each, followed by semifinals and final) were randomly evaluated. Games lasted 70 min (two periods of 35 min with 15 min rest interval), and they were played on consecutive days with 24 h between each game. Delayed onset muscle soreness (DOMS) and Total Quality Recovery (TQR) were measured before group phase games (n= 31) and semifinals games (n= 18). The internal game load was measured by the session rate of perceived exertion (session-RPE) method. TQR was higher before the first game when compared to the other games (p< 0.001). DOMS increased after the first game and did not return to baseline before the fourth game. Both session-RPE and internal load of the fourth game were higher than in the other games (p< 0.001). In addition, there was no correlation between internal game load and TQR (p> 0.05). The monotony observed during the evaluated period was 3.1±2.0 AU. The results indicate that the 24 h rest period seems to be insufficient for complete recovery of U-19 soccer school athletes, suggesting the organization of U-19 school soccer competitions with higher rest interval between games and search for methods to increase the recovery rate.

Resumo O presente estudo objetivou analisar o efeito de uma competição escolar de futebol com jogos em dias consecutivos no estado de recuperação física de jogadores sub-19. Foram avaliados, de forma aleatória, 31 atletas escolares (17,1±1,1 anos) participantes de uma competição escolar de futebol de campo sub-19, composta de duas chaves com quatro equipes cada, seguido de semifinais e final. Os jogos tiveram 70 min de duração (dois tempos de 35 min com 15 min de intervalo), e foram realizados em dias consecutivos com intervalo de 24h entre cada jogo. Foi medida a dor muscular de início tardio (DOMS) e Qualidade Total de Recuperação (QTR) antes de cada jogo da primeira fase (n= 31) e da semifinal (n=18). A carga interna dos jogos foi medida a pelo método da percepção subjetiva do esforço da sessão (PSE-sessão). A QTR foi maior antes do primeiro jogo em comparação com os demais jogos (p< 0.001). A DOMS aumentou após o primeiro jogo e não retornou aos valores basais antes do quarto jogo (p< 0.001). A PSE-sessão e a carga interna do quarto jogo foram maiores que as dos demais jogos (p< 0,001). Em adição, não houve correlação entre a carga interna do jogo e a QTR (p> 0,05). A monotonia encontrada no período avaliado foi de 3,1±2.0 UA. Os resultados indicam que o período de 24h parece ser insuficiente para a completa recuperação de atletas escolares de futebol sub-19, sugerindo a organização de competições escolares de futebol sub-19 com maior intervalo entre os jogos e busca por métodos que acelerem a recuperação.

Sarcopenia and cardiovascular risk in physically active adult and elderly women / Sarcopenia e risco cardiovascular em mulheres adultas e idosas fisicamente ativas / Sarcopenia y riesgo cardiovascular en mujeres adultas y mayores fisicamente activas

The purpose of this study was to assess the prevalence of sarcopenia and its association with risk factors for cardiovascular diseases (CVD) in non-sedentary women. Study participants were 124 women (control group (CG) n = 33; 24.5 ± 2.9 years and study group (SG) n = 91; 61.9 ± 8.7 years). Anthropometric measurements, blood parameters, body composition (DXA), anthropometric indices and questionnaire answers were analyzed. Sarcopenia was considered as a standard deviation below mean values for young people, corresponding to 7.3 kg/m2 and classifying 34.1% of SG as sarcopenic. Prevalence of risk for CVD considered low, moderate and high was 21%, 60% and 19%, respectively. Logistic regression showed no relationship between sarcopenia and risk factors for CVD, except for body mass index as a protection factor. There was a tendency for sarcopenia to assume associations as risk factor for variables smoking, triglycerides, obesity, abdominal fat, and Framingham Risk Score and as a protection factor for variable physical activity level.

Objetivou-se verificar a prevalência de sarcopenia e sua associação com fatores de risco para doenças cardiovasculares (DCV) em mulheres fisicamente ativas. Participaram 124 mulheres (Grupos Controle (GC) n = 33; 24,5 ± 2,9 anos e de Estudo (GE) n = 91; 61,9 ± 8,7 anos). Analisaram-se medidas antropométricas, parâmetros sanguíneos, composição corporal (DEXA), índices antropométricos e respostas de questionários. Considerou-se sarcopenia um desvio-padrão abaixo da média para a população jovem, correspondendo a 7,3 kg/m2, classificando 34,1% do GE como sarcopênico. Prevalência do risco para DCV considerando baixo, moderado e alto foi, respectivamente, 21%, 60% e 19%. A regressão logística não mostrou relação entre sarcopenia e fatores de risco para DCV, exceto para o índice de massa corporal como fator de proteção. Observou-se tendência da sarcopenia assumir associações como fator de risco nas variáveis tabagismo, triglicerídeos, obesidade, gordura abdominal e Escore de Risco de Framingham e como fator de proteção na variável nível de atividade física.

El objetivo fue comprobar la prevalencia de sarcopenia y su relación con factores de riesgo para el desarrollo de enfermedades cardiovasculares (ECV) en mujeres activas. Participaron 124 mujeres (Grupo Control (GC) n = 33; 24,5 ± 2,9 años y de Estudio (GE) n = 91; 61,9 ± 8,7 años), a las cuales se le realizó: cuestionario, antropometría, análisis bioquímico y densitometría ósea (DEXA). La sarcopenia fue considerada una desviación estándar por debajo de la media para la población joven, lo que corresponde a 7,3 kg/m2, clasificando 34,1% el GE como sarcopénico. La prevalencia del riesgo para ECV considerando bajo, moderado y alto riesgo fue respectivamente, 21%, 60% y 19%. La regresión logística no mostró relación entre sarcopenia y factores de riesgo para ECV, excepto para el índice de masa corporal como factor de protección. También se observó que la sarcopenia está asociada a factores de riesgo como tabaquismo, hipertrigliceridemia, obesidad, grasa abdominal y puntuación de riesgo de Framingham. La variable de actividad física se mostró como factor de protección.

Análise do modelo de avaliação física aplicado aos árbitros de futebol pela FIFA / Analysis of the FIFA's model of physical evaluation applied to the soccer referees

INTRODUÇÃO: A fim de controlar e selecionar os árbitros para atuação no futebol profissional, a Fédération Internacionale de Football Association (FIFA) propôs a realização de testes físicos. Entretanto, a proposta inicial de avaliação sofreu modificações com o passar dos anos, e o modelo atual parece não ser ideal para avaliar os árbitros, de acordo com o perfil de exigência física demonstrada durante os jogos. OBJETIVOS: Assim, os objetivos deste estudo foram: identificar a carga física de árbitros de futebol e determinar as demandas fisiológicas associadas ao esforço físico realizado durante as partidas oficiais e analisar o modelo atual de avaliação física dos árbitros de futebol. CONCLUSÃO: O árbitro percorre em média 10.000m durante uma partida, sendo a maior parte do tempo percorrida com atividades de baixa intensidade. O perfil de movimentação é intermitente e a demanda energética tem predominância do sistema aeróbico, com importante participação do sistema anaeróbico. Os testes aplicados atualmente não são compatíveis com o padrão de exigência física de um árbitro durante uma partida de futebol.

INTRODUCTION: In order to control and select the referees for performance in professional soccer, the Fédération Internacionale de Football Association (FIFA), considered the accomplishment of physical tests. However, the initial proposal of evaluation suffered modifications with the passing of the years, and the current model seems not to be ideal to evaluate the referees, in accordance with the physical profile requirement demonstrated during the games. OBJECTIVE: Therefore, the objectives of this study were: to identify the physical load of soccer referees in official games and to determine the physiological demands associates to the physical effort during the official games; and to analyze the current model of physical evaluation of the soccer referees. CONCLUSION: Referees cover an average of 10,000 meters during a game, being most of the time done with activities of low intensity. The activity profile is intermittent and the energy demand has predominance of the aerobic system, with important participation of the anaerobic system. The current tests applied are not compatible with the standard of physical requirement of a referee during a soccer game.