Fat-Free Mass Index for body composition analysis in pediatric sport: a cross-sectional study.

BACKGROUND: Analyzing fat free mass (FFM) helps sport professionals during the prescription of sport training for children and adolescents in a sport initiation program. In this way, it is possible to determine fat mass (FM) (FFM subtracted from total body weight) and design interventions to increase FFM and reduce %F, making it possible to maximize performance in relation to the physical demands of sport. However, there is still no reliable anthropometric index to analyze FFM in this population. The aim the present study was to develop the Fat-Free Mass Index (FFMI) for pediatrics of both sexes. METHODS: Cross-sectional study with a sample composed of 254 pediatrics (139 males [age: 13.0±2.3] and 115 females [age: 12.5±2.2]), from a sports initiation school. We divided the sample into the groups: 1) development (N.=169); and 2) cross-validation (N.=85). The body composition was analyzed by dual-energy X-ray absorptiometry (DXA), in addition we acquired anthropometric data (height, body weight and hip circumference) for the development of the FFMI - Pediatric (FFMIp). By means of linear regression we tested the predictive power of FFM using DXA as a reference method, then we developed FFMIp and tested its reliability and validity in relation to DXA. RESULTS: FFMIp consisted of: -16.679 + (0.615 × body mass (kg)) - (2.601 × sex) + (0.618 × age(years)) - (0.332 × hip(cm)) + (0.278 × stature(cm)), where for sex 0 = male and 1 = female. For the FFM analysis, FFMIp showed no significant difference from DXA (P>0.05). It also showed significant accuracy (Cb>0.960), precision (ρ>0.990) and agreement (CCC>0.960) for both groups (development and cross-validation). CONCLUSIONS: Pediatric FFMI proposed by this study proved to be valid for the analysis of fat-free mass in pediatric athletes of sports initiation of both sexes.

Metabolic Profile and Body Composition in Twins Concordant and Discordant for Physical Exercise.

The aim of this study was to evaluate the differences in the metabolic profile and body composition of monozygotic (MZ) twins concordant and discordant for the practice of physical exercise. The sample consisted of 92 MZ twins (72.5% female and 27.5% male, mean age 25.4 ± 5.69 years), registered with the Brazilian Registry of Twins, residing in Natal, Brazil. Data collection was carried out between the years 2016 and 2018. On day 1, subjects underwent a whole-body fitness evaluation, including measures of weight, height, body composition by Dual-Energy X-ray Absorptiometry and the Cardiorespiratory Exercise Test. On day 2, 10 ml blood samples were collected (overnight fasting) to determine the lipid profile and fasting glucose. The sample was separated into three groups: Active Concordant twins (Concordant A, n = 44 subjects), Inactive Concordant twins (Concordant I, n = 22 subjects) and Discordant pairs for Physical Exercise (Discordant PE, n = 26 subjects). The results demonstrated a difference between the discordant twins for exercise and also between the active versus sedentary groups, indicating a causal effect of exercise on the fat percentage, maximum oxygen consumption (VO2max) and second ventilatory threshold variables. Between groups, a difference was also observed between the groups in ventilatory threshold, very low-density lipoprotein and triglycerides. We concluded that, regardless of genetics, the practice of physical exercise was sufficient to generate alterations in body composition and VO2max in MZ twins, but not in the lipid profile or fasting glucose.

Influence of curcumin on glycemic profile, inflammatory markers, and oxidative stress in HIV-infected individuals: A randomized controlled trial.

To evaluate the influence of curcumin supplementation on the glycemic profile, inflammatory markers, and oxidative stress in HIV-infected individuals under antiretroviral therapy. This double-blind, crossover, randomized clinical trial was composed of 20 subjects arranged initially into experimental group (n = 10) and placebo group (n = 10) groups, receiving 1,000 mg curcumin/day or microcrystalline cellulose/day, respectively, during a 30-day period and 12-day washout. Subsequently, the groups were switched to follow the crossover design. Fasting glucose and insulin, IL-10, tumor necrosis factor alpha, malonialdehyde, and reduced glutathione were measured. Food consumption was evaluated as a control variable. Descriptive statistics are presented as mean and standard deviation, and inferential analyses were performed from two-way analysis of variance and the magnitude of the effect. No significant improvements were observed in the glycemic, inflammatory, or oxidative stress profiles. Although the mean serum fasting glucose levels and the homeostatic model assessment index presented qualitative improvement in the CG, this result should be interpreted with caution since the observed variation may represent acceptable fluctuation, in addition to the small difference between the means, added to the large variation observed in the standard deviation. Supplementation with curcumin in HIV-infected individuals undergoing antiretroviral therapy and training did not improve the glycemic, inflammatory, or oxidative stress profiles.

Skeletal age and explosive strength in young volleyball players / Idade óssea e força explosiva de jovens praticantes de voleibol

Abstract Identifying different anthropometric, physiological and motor aspects is essential to obtain success in sports practice. However, these components may be developed in same age subjects differently, in part due biological development. The aim of the study was compare and correlate the explosive strength to biological maturation by sex, obtained by estimation of skeletal age based on anthropometric variables. The sample consisted of 239 subjects of both sexes, aged 10 to 13 years. Maturation was assessed by skeletal age predictive equation and upper and lower limbs explosive strength using medicine ball throw test and vertical jump, respectively. Skeletal age was assessed by skeletal age using a predictive anthropometrical based equation. Upper and lower limbs explosive strength were evaluated by medicine ball throwing test and vertical jump test, respectively. Post hoc analysis showed delayed biological development subjects had worst medicine ball throwing test performance than accelerated boys (p=0.001; d=0.96) and girls (p< 0.01; d= 2.01); regarding to vertical jump test, worst performance was also detected to maturational delayed boys when compared to accelerated ones (p=0.24; d=1.1) and girls (p=0.007; d=0.75). Regression analysis showed skeletal age explained variance of 36% and 19.2% for boys and 45.2% and 16.1% for girls upper and lower limbs explosive strength. Skeletal age is positively related to upper and lower limbs explosive strength and show higher performance for accelerated biological development young players when compared to delayed ones, independently from sex.

Resumo Para se alcançar o sucesso no esporte, a identificação de diferentes aspectos antropométricos, motores e fisiológicos são imprescindíveis. Porém, esses componentes podem se desenvolver diferentemente em indivíduos na mesma faixa etária, em parte pelo desenvolvimento biológico. O objetivo do estudo foi comparar e relacionar a força explosiva com a maturação biológica de acordo com o sexo. A amostra foi composta por 239 sujeitos, com idades entre 10 a 13 anos. A idade óssea foi estimada por uma equação preditora baseada em variáveis antropométricas. A força explosiva de membros superiores e inferiores foram avaliadas através do teste de arremesso de medicine ball e de salto vertical, respectivamente. A análise de post hoc mostrou que os sujeitos com desenvolvimento biológico atrasado obtiveram o pior desempenho no teste de arremesso de medicine ball quando comparados com o grupo acelerado dos meninos (p=0.001; d=0.96) e meninas (p< 0.01; d= 2.01); em relação ao teste de salto vertical, desempenho inferior também foi observado para o estágio atrasado quando comparado com o grupo acelerado dos meninos (p=0.24; d=1.1) e meninas (p= 0.007; d=0.75). Análise de regressão demonstrou que 36% e 19,2% da variância no desempenho da força explosiva de membros superiores e inferiores foi compartilhada pela idade óssea dos meninos, e 45,2% e 16,1%, respectivamente, nas meninas. Conclui-se que a força explosiva de membros superiores e inferiores se relaciona de forma positiva com a idade óssea, sendo o desempenho destes componentes superiores em jovens com desenvolvimento biológico acelerado, quando comparados com o desenvolvimento atrasado, independente do sexo.