Danilo Rodrigues Pereira da Silva

Validade dos métodos para avaliação da gordura corporal em crianças e adolescentes por meio de modelos multicompartimentais: uma revisão sistemática

OBJECTIVE To analyze the validity of methods to assess body fat in children and adolescents using a systematic review. METHODS The search was conducted by two independent researchers using the MEDLINE, BioMed Central, SciELO and LILACS electronic databases. For inclusion, the articles should be written in English or Portuguese, and must have used multi-compartment models as the criterion measure of the model, with body fat measurement of whole body in non-athlete children and adolescents. RESULTS A preliminary search resulted in 832 studies. After all selection steps were performed, 12 articles were included. The selected studies were published between 1997 and 2010, whose samples consisted of children and adolescents with levels of relative body fat ranging from 20.7% to 41.4%. The methods used were: dual energy X-ray absorptiometry (58.3%), isotope dilution (41.6%), skinfold thickness (33.3%), hydrostatic weighing (25%), bioelectrical impedance analysis (25%), air displacement plethysmography (16.6%), and total body electrical conductivity (8.3%). CONCLUSIONS Based on the analysis of the studies, isotope dilution and air displacement plethysmography methods were the most reliable, despite the limited number of studies. As for clinical use or for population-based studies, the equation of Slaughter et al. (1998), which uses the triceps and subscapular skinfolds thickness, showed the best results for assessment of body fat in this population.

Biological Maturation, Central Adiposity, and Metabolic Risk in Adolescents: A Mediation Analysis

BACKGROUND Earlier biological maturation has been related to increased metabolic risk. In this study, we verified mediating effects by central adiposity of the relationship between somatic maturity and metabolic risk factors in adolescents. METHODS In a cross-sectional study, 1034 adolescents aged 10-16 years from Londrina/PR/Brazil were evaluated. The age of peak height velocity (PHV) method was used to evaluate somatic maturity. Central adiposity was estimated through waist circumference measurements. Fasting glucose, triglycerides, high-density lipoprotein cholesterol (HDL-C), and blood pressure were measured as metabolic risk indicators. Physical activity (Baecke questionnaire) and cardiorespiratory fitness (20-m shuttle run test) were used as covariates. RESULTS Except for fasting glucose, waist circumference showed partial or full mediation of the relationship between maturity and the following metabolic risk factors with their respective z-score values: triglycerides (boys = -3.554 vs. girls = -5.031), HDL-C (boys = +5.300 vs. girls = +5.905), systolic blood pressure (boys = -3.540 vs. girls = -3.763), diastolic blood pressure (boys = -2.967 vs. girls = -3.264), and metabolic risk score (boys = -5.339 vs. girls = -6.362). CONCLUSIONS The results suggest that central obesity plays a mediating role in the relationship between somatic maturation and metabolic risk during adolescence.

Correlates of sports practice, occupational and leisure‐time physical activity in Brazilian adolescents

To analyze the relationship between different physical activity (PA) domains and sociodemographic, psychological, behavioral and biological factors in Brazilian adolescents.

Cardiorespiratory fitness is related to metabolic risk independent of physical activity in boys but not girls from Southern Brazil

Our aim was to determine the relationship between cardiorespiratory fitness (CRF) and metabolic risk in adolescents from Southern Brazil.

Static stretching and performance in multiple sets in the bench press exercise.

Abstract Ribeiro, AS, Romanzini, M, Dias, DF, Ohara, D, da Silva, DRP, Achour, A Jr, Avelar, A, and Cyrino, ES. Static stretching and performance in multiple sets in the bench press exercise. J Strength Cond Res 28(4): 1158–1163, 2014—The purpose of this study was to analyze the acute effect of static stretching on the performance of multiple sets in the bench press (BP) exercise. Fifteen men (26.2 ± 0.7 years, 72.4 ± 1.3 kg, 1.78 ± 0.1 m, 22.8 ± 0.3 kg·m−2) performed 4 sets of the BP exercise at 80% of 1 repetition maximum until concentric failure, both in the stretching condition (SC) and control condition (CC). The rate of force decline between the first and the fourth set was used as fatigue index. A randomized, counterbalanced, crossover design was performed with 48 hours between each session. Two static stretching exercises (pectoral and triceps brachii muscles) were performed in a single set before BP in SC, whereas in CC, subjects remained at rest for 150 seconds. For each stretching exercise, the muscle was held at the maximal stretched position for 30 seconds. No significant difference (p > 0.05) was identified for total repetitions performed in 4 sets (SC, 21.3 ± 0.7% vs. CC, 20.5 ± 0.7%) and in the fatigue index (SC, 75.5 ± 1.3% vs. CC, 73.2 ± 1.9%). The results suggest that the performance of multiple sets in the BP exercise does not seem to be influenced by previous static stretching.

Effect of Two- Versus Three-Way Split Resistance Training Routines on Body Composition and Muscular Strength in Bodybuilders: A Pilot Study

The purpose of this study was to compare different split resistance training routines on body composition and muscular strength in elite bodybuilders. Ten male bodybuilders (26.7 ± 2.7 years, 85.3 ± 10.4 kg) were randomly assigned into one of two resistance training groups: 4 and 6 times per week (G4× and G6×, respectively), in which the individuals trained for 4 weeks, 4 sets for each exercise performing 6-12 repetitions maximum (RM) in a pyramid fashion. Body composition was assessed by dual energy X-ray absorptiometry, muscle strength was evaluated by 1RM bench-press testing. The food intake was planned by nutritionists and offered individually throughout the duration of the experiment. Significant increases (p < .05) in fat-free mass (G4× = +4.2%, G6× = +3.5%) and muscular strength (G4× = +8.4%, G6× = +11.4%) with no group by time interaction were observed. We conclude that 4 and 6 weekly sessions frequencies of resistance training promote similar increases in fat-free mass and muscular strength in elite bodybuilders.

Birth weight, biological maturation and obesity in adolescents: a mediation analysis

This study was aimed to investigate associations between birth weight and multiple adiposity indicators in youth, and to examine potential mediating effects by biological maturation. This was a school-based study involving 981 Brazilian adolescents aged between 10 and 17 years. Birth weight was reported retrospectively by mothers. Maturation was estimated by age of peak height velocity. Adiposity indicators included body mass index (BMI), waist circumference and percent body fat estimated from triceps and subscapular skinfolds. Multilevel mediation analyses were performed using the Sobel test, adjusted for chronological age, gestational age, cardiorespiratory fitness and socio-economic status. Except for body fat in girls, biological maturation partly or fully mediated (P<0.05) positive relationships between birth weight with all other obesity indicators in both sexes with their respective values of indirect effects with 95% confidence intervals: BMI [boys: 0.44 (0.06-0.82); girls: 0.38 (0.13-0.64)], waist circumference [boys: 1.14 (0.22-2.05); girls: 0.87 (0.26-1.48)] and body fat [boys: 0.60 (0.13-1.07)]. To conclude, birth weight is associated with elevated obesity risk in adolescence and biological maturation seems to at least partly mediate this relationship.

Correlates of Blood Pressure According to Early, On Time, and Late Maturation in Adolescents

The aim of this study was to estimate the prevalence and correlates of blood pressure (BP) according to somatic maturation in Southern Brazilian adolescents. A total of 1321 adolescents participated in the study (732 girls), aged between 10 and 16 years, enrolled in public schools. The assessment of BP was performed using oscillometric equipment. Measurements of body weight, height, waist circumference, and skinfold thickness were performed. Somatic maturation was estimated by the age at peak height velocity. Behavioral and hereditary variables were obtained using a questionnaire. Early‐maturing adolescents had the highest prevalence of high BP (28%; 95% confidence interval, 24.6–33.5) compared with other maturational groups (P=.003). In late‐maturing adolescents, the variables associated with BP were paternal hypertension (systolic BP: β=4.9; diastolic BP: β=5.3) and early physical activity (systolic BP: β=−4.0; diastolic DBP: β=−3.6). In average‐maturing adolescents, waist circumference (systolic BP: β=0.3), body mass index (diastolic BP: β=0.5), and mothers hypertension (diastolic BP: β=1.8) were positively related to BP. In early‐maturing adolescents, only waist circumference (systolic BP: β=0.3; diastolic BP: β=0.3) was associated with BP. The authors conclude that the prevalence of high BP is greater in adolescents with early maturity and the outcome appears to be related to biological indicators in this group. On the other hand, in late‐maturing adolescents, behavioral and hereditary variables are more related to BP.

Cardiorespiratory fitness effect may be under-estimated in ‘fat but fit’ hypothesis studies

Abstract Background: Both cardiorespiratory fitness and body fat have been independently related to metabolic syndrome in adolescents; however, the strength of these relationships seems to be dependent on the outcome composition. Aim: To analyse the relationship between cardiorespiratory fitness and body fat combined with different indicators of metabolic risk in adolescents. Subjects and methods: The sample was composed of 957 adolescents (58.7% girls). Cardiorespiratory fitness was obtained using the 20-metre shuttle run test and skinfold thickness was collected for body fat estimation. Metabolic risk score was calculated from waist circumference, systolic and diastolic blood pressure, glucose, HDL cholesterol and triglycerides measurements and an alternative outcome without the central obesity indicator was adopted. Chronological age and somatic maturity were used as covariates. Results: Higher metabolic risk was observed in the highest fat/lowest fit adolescents (p < .05), regardless of sex and outcome. In the regression models, for full metabolic risk score, body fat presented higher coefficients compared to cardiorespiratory fitness in both sexes (boys: 0.501 vs −0.097; girls: 0.485 vs −0.087); however, in the metabolic risk without waist circumference, the coefficients became closer (boys: 0.290 vs −0.146; girls: 0.265 vs −0.120), with a concomitant decrease in body fat and increase in cardiorespiratory fitness coefficients. Conclusion: These findings suggest that body fat is strongly related to cardiovascular risk, but, when the outcome is calculated without the central obesity indicator, cardiorespiratory fitness becomes more related to metabolic risk.

Effect of Conjugated Linoleic Acid Associated With Aerobic Exercise on Body Fat and Lipid Profile in Obese Women: A Randomized, Double-Blinded and Placebo-Controlled Trial

The aim of this study was to analyze the effects of 8 weeks of conjugated linoleic acid (CLA) supplementation associated with aerobic exercise on body fat and lipid profile on obese women. We performed a randomized, double-blinded and placebo-controlled trial with 28 obese women who received 3.2 g/day of CLA or 4 g/day of olive oil (placebo group) while performing an 8-week protocol of aerobic exercise. Dietary intake (food record), body fat (dual-energy X-ray absorptiometry), and biochemical analysis (blood sample) were assessed before and after the intervention period. Independent of CLA supplementation, both groups improved (p < .05) oxygen uptake (CLA group, 13.2%; PLC group, 14.8%), trunk fat (CLA group, -1.0%; PLC group, -0.5%), leg fat (CLA group, -1.0%; PLC group, -1.6%), and total body fat (CLA group, -1.7%; PLC group, -1.3%) after the 8-week intervention. No main effect or Group × Time interaction was found for total cholesterol, triglycerides, and plasma lipoproteins (p > .05). We conclude that CLA supplementation associated with aerobic exercise has no effect on body fat reduction and lipid profile improvements over placebo in young adult obese women.