Can skinfold thickness equations be substituted for bioimpedance analysis in children?

Abstract Objective: The aim of the present study was to evaluate the agreement between the most used skinfold thickness equations with multi-frequency bioimpedance analysis in the prediction of body fat levels in children. Method: A cross-sectional study of healthy Brazilian community-dwelling individuals. The anthropometric assessment included height, body mass, arm circumference, and waist circumference. The percentage of body fat was obtained by measuring skinfold thickness equations and using bioimpedance analysis, and skinfold thickness was measured using a scientific skinfold caliper. Bland-Altman plot analysis was used to verify the agreement between the methods. Results: There were 439 children and adolescents evaluated, with a mean age of 11.6 ± 3.7 years. The mean body fat by bioimpedance analysis was 22.8% ± 10.4%, compared to 22.4% ± 8.8% by Slaughter (1), 20.4% ± 9.2% by Slaughter (2), 19.6% ± 4.4% by Goran, and 24.7% ± 10.0% by Huang equations. Bland-Altman plot analysis revealed limits of agreement greater than 8% between the bioimpedance analysis approach and equations, exceeding the clinically acceptable limit predefined a priori. None of the equations had good agreement with bioimpedance analysis. Conclusion: It was concluded that skinfold thickness and bioimpedance analysis should not be used interchangeably in children and adolescents.

Thermoregulation of competitive artistic gymnastic athletes and non-athlete girls exercising in the heat / Termorregulação em atletas de ginástica artística e meninas não-atletas durante exercício no calor

Abstract It’s unclear whether the combination of intense, chronic training and heat exposure during prepubescence improves thermoregulatory responses to exercise in artistic gymnastics athletes. The objective of this study was to compare thermoregulatory and perceptual responses between artistic gymnastics athletes and non-athlete girls while exercising both in heat and thermoneutral conditions. Seven athletes (8.7 ± 1.3 yrs) and 7 nonathletes (9.4 ± 1.5 yrs) cycled for 30 min at load (W) of ~55% VO2peak, on two separate occasions in a randomized order: heat (35˚C, 40% relative humidity) and thermoneutral conditions (24˚C, 50% relative humidity). Rectal temperature, heart rate, rate of perceived exertion, thermal sensation, thermal comfort and irritability were measured throughout the exercise. Initial rectal temperature was similar between athletes and non-athletes in both heat (37.2 ± 0.4 vs. 37.4 ± 0.2˚C, respectively) and thermoneutral conditions (37.3 ± 0.2 vs. 37.3 ± 0.3˚C). Final rectal temperature was similar between groups (38.0 ± 0.2 vs. 38.2 ± 0.2˚C in heat and 37.8 ± 0.2 vs. 37.9 ± 0.2˚C in thermoneutral conditions). Initial heart rate was lower in athletes in the heat (76 ± 7 vs. 91 ± 11 bpm, P = 0.01); however, throughout cycling, it became similar between groups. Athletes reported similar perceptual responses compared to non-athletes, with the exception of higher thermal comfort in the 10th minute of exercise in thermoneutral conditions (P = 0.003). It was concluded that athletes were similar to non-athletes with respect to thermoregulatory and perceptual responses during 30 min of cycling at similar relative intensities.

Resumo Não está claro se a combinação de treinamento crônico intenso e a exposição ao calor durante a pré-adolescência melhoram as respostas termorregulatórias ao exercício em atletas de ginástica artística (GA). Objetivou-se comparar as respostas termorregulatórias e perceptivas entre atletas de GA e não-atletas durante uma sessão de exercício nas condições de calor (CC) e termoneutra (CT). Sete atletas (8,7 ± 1,3 anos) e 7 não-atletas (9,4 ± 1,5 anos) pedalaram por 30 minutos com carga (W) referente ~55% VO2pico, em CC (35˚C e 40% umidade relativa) e CT (24˚C e 50% umidade relativa). A temperatura retal (Tre), frequência cardíaca (FC), taxa de percepção de esforço, sensação e conforto térmico e irritabilidade foram medidas durante o exercício. Tre inicial foi similar entre atletas e não-atletas em CC (37,2 ± 0,4 vs. 37,4 ± 0.2˚C, respectivamente) e CT (37,3 ± 0,2 vs. 37,3 ± 0.3˚C). Tre final foi similar entre os grupos (38,0 ± 0,2 vs. 38,2 ± 0.2˚C na CC; e 37,8 ± 0,2 vs. 37,9 ± 0.2˚C na CT). FC inicial foi menor nas atletas na CC (76 ± 7 vs. 91 ± 11 bpm, P = 0,01). No entanto, ao longo das pedaladas, foi similar em ambos os grupos. As respostas perceptivas foram similares entre os grupos, com exceção ao maior conforto térmico das atletas aos 10 minutos de pedalada (P= 0,003). As atletas de GA apresentaram respostas termorregulatórias similares as não-atletas durante 30 minutos de pedalada em similar intensidade relativa nas CC e CT.

Correlação socioeconômica e antropométrica em idosos praticantes e não praticantes de exercícios físicos / Correlation socioeconomic and anthropometric in elderly practitioners and not practitioners of physical activity

Este estudo, baseado na Tese do Programa de Doutorado em Gerontologia Biomédica, avaliou, a partir de uma análise parcial quantitativa, a correlação do perfil socioeconômico e antropométrico em idosos praticantes e não praticantes de exercícios físicos regulares, assistidos pelo Centro Universitário Vila Fátima e pela Faculdade de Educação Física da PUCRS. Foi selecionada uma amostra inicial de conveniência de 50 idosos, sendo 25 em cada grupo ? praticante e não praticante. Do total, observou-se que a maioria era do sexo feminino, com idade entre 62 e 86 anos, ensino fundamental incompleto, cuja renda era acima do salário mínimo e com histórico familiar de doenças cardiovasculares. Entre os grupos ocorreram diferenças significativas nas seguintes variáveis: fumo (p<0,001), hereditariedade (p<0,001), Dobra Cutânea Subescapular (DCS) (p<0,001) e Dobra Cutânea Tricipital(DCT) (p<0,001). Observou-se mudança no percentual de gordura (p= 0,0001), assim como variação de Massa Magra em quilos (p= 0,0293) e de massa gorda em quilos entre praticantes e não praticantes (p= 0,0004), além da diferença na relação cintura/quadril nesses grupos (p= 0,0257). Nesse sentido, evidencia-se que a prática regular de exercícios físicos em idosos é essencial para a prevenção de doenças, manutenção e recuperação da saúde.

This study is part of a PhD thesis in Biomedical Gerontology, with partial quantitative analysis, which aimed to correlate on anthropometric and socioeconomic profile of elderly practitioners and non-practitioners of regular exercise, attended at Villa Fatima University Center and the Faculty of Physical Education PUCRS, selecting a convenience sample (initial partial) of 50 seniors (25 practitioners and 25 non-practicing). Of these, we found that the majority were women, between 62 to 86 years, with Incomplete Elementary School, and earned more than minimum wage and with a family history of cardiovascular disease. Between groups (practitioners and non-practitioners) significant differences in the following variables: smoking (p <0.001), heredity (p <0.001), subscapular skinfold (DCS) (p <0.001) and triceps skinfold (TSF) (p <0.001). Observed difference in fat percentage between the groups (p = 0.0001), as well as the difference of Lean Body Mass in kilograms (p = 0.0293) and fat mass in kilograms between practitioners and non-practitioners (p = 0.0004), besides the difference in the waist / hip ratio in these groups (p = 0.0257) Therefore, we recommend the regular practice of physical exercise in the elderly, because it is essential for the prevention of disease and the maintenance and restoration of health.