Bone mineral density associated with physical traits and lifestyle in adolescents

INTRODUÇÃO: No Brasil, ainda são poucos os estudos que apresentam dados relevantes sobre fatores relacionados às características físicas ou estilo de vida e a densidade mineral óssea (DMO) de adolescentes do sexo feminino. OBJETIVO: Identificar e verificar a contribuição das características físicas e de estilo de vida relacionadas à DMO de adolescentes do sexo feminino. MÉTODOS: A amostra deste estudo foi composta por 329 meninas com idades entre 10 e 20 anos. Como características físicas, foram avaliados: peso corporal, estatura, índice de massa corporal, estágio de maturação sexual, raça e pigmentação cutânea. Já para o estilo de vida, os seguintes fatores foram avaliados: consumo diário de cálcio, nível de atividade física (NAF) e nível socioeconômico (NSE). A densidade mineral óssea (DMO) do corpo inteiro, da coluna lombar e do colo do fêmur foram avaliados pela densitometria óssea. As relações existentes entre variáveis dependentes e independentes foram avaliadas pela correlação de Pearson (r) e regressão múltipla Stepwise (p < 0,05). RESULTADOS: A DMO dos três sítios ósseos tende a aumentar conforme o aumento do peso corporal, estatura, IMC, idade e estágio de maturação sexual (r ≥ 0,43; p < 0,01). Por outro lado, somente o NAF (r = 0,12; p < 0,05) e o NSE (r = 0,14; p < 0,05) correlacionaram-se positivamente com a DMO. O peso corporal, estágio de maturação sexual, idade, consumo de cálcio, NSE e NAF explicaram de 48 a 68% da variação da DMO das adolescentes. CONCLUSÃO: Os resultados sugerem que a utilização de critérios como peso corporal, idade e maturação sexual sejam os mais indicados para controlar as variações da DMO de adolescentes do sexo feminino. Além disso, o NSE, o NAF e o consumo diário de cálcio possuem uma pequena participação na variação da DMO das adolescentes quando comparados com as características físicas.INTRODUCTION: Just a few studies have evaluated physical traits, lifestyle and bone mineral density (BMD) acquisition in Brazilian female adolescents. OBJECTIVE: To identify physical traits and lifestyle factors related to BMD in Brazilian female adolescents. METHODS: 329 healthy adolescent girls aged between 10 and 20 years participated in this study. The physical characteristics evaluated were: body weight, stature, body mass index, pubertal stage, self-declared ethnicity and skin color. Concerning lifestyle, the following factors were evaluated: socioeconomic status (SES), physical activity level (PAL) and daily calcium intake. Additionally, total body, lumbar spine and femoral neck bone mineral density (BMD) was assessed by bone densitometry. Pearson's coefficient of correlation (r) and stepwise regression analysis were employed to check dependent and independent variables correlation (p < 0.05). RESULTS: Total body, lumbar spine and femoral neck BMD increase as body weight, height, BMI, age and pubertal stage increase (r ≥ 0.43; p<0.01). On the other hand, only SES (r = 0.14; p<0.05) and PAL (r = 0.12; p<0.05) were correlated. After stepwise regression, body weight, pubertal stage, age, height, calcium intake, SES, and PAL explained around 48-68% for BMD variation in female adolescents. CONCLUSION: The results suggest body weight, age and pubertal stage should be used as control variables for BMD variations in female adolescents. Furthermore, SES, PAL and dialy calcium intake were less important than physical traits for BMD during adolescence

Efeito da Ansiedade Competitiva Sobre a Tomada de Decisão do Passe em Atletas de Futebol da Categoria Sub-17

No se sabe si la ansiedad competitiva genera efectos en el rendimiento de toma de decisiones en los atletas. El objetivo del estudio fue analizar el efecto de la ansiedad competitiva sobre toma de decisiones del pase en futbolistas jóvenes. Se trata de una investigación prospectiva, cuya muestra fue formada por 40 jugadores de la categoría sub-17. La versión en portugués del Competitive State Anxiety Intentory se completó 45 minutos antes del comienzo de una partida de fútbol. La toma de decisiones se evaluó mediante los criterios del instrumento de evaluación del rendimiento del juego por medio del Game Performance Assessment Instrument. Los resultados mostraron una influencia significativa de la ansiedad cognitiva (R² = .20; p = .001), de la ansiedad somática (R² = .45; p = .001) y de la autoconfianza sobre el índice de toma de decisión del pase (R² = .31; p = .001). Se concluyó que la ansiedad competitiva puede considerarse un factor que interviene en la toma de decisiones del pase de jóvenes jugadores de fútbol de sexo masculino.Não se sabe se a ansiedade competitiva acarreta efeito no desempenho da tomada de decisão em atletas. O objetivo do estudo foi analisar o efeito da ansiedade competitiva sobre a tomada de decisão do passe em jovens atletas de futebol. Trata-se de uma investigação prospectiva, cuja amostra foi composta por 40 atletas de futebol da categoria sub-17. A versão em língua portuguesa do Competitite State Anxiety Inventory (CSAI-2R) foi preenchida 45 minutos antes do início de uma partida de futebol. A tomada de decisão foi avaliada pelos critérios do Game Performance Assessment Instrument. Os resultados apontaram influência significativa da ansiedade cognitiva (R² = .20; p = .001), da ansiedade somática (R² = .45; p = .001) e da autoconfiança sobre o índice de tomada de decisão do passe (R² = .31; p = .001). Concluiu-se que a ansiedade competitiva pode ser considerada um fator interveniente na tomada de decisão do passe de jovens atletas de futebol do sexo masculino.It is not known if competitive anxiety affects decision-making performance in athletes. This study aimed to analyze the effect of competitive anxiety on passing decision-making in young soccer players. This is a prospective study, whose sample consisted of 40 soccer athletes of the under-17 category. The Portuguese version of the Competitive State Anxiety Inventory (CSAI-2R) was filled out by athletes 45 minutes before the start of a soccer match. Decision-making was evaluated in a real game situation. The analysis and categorization of actions were based on the Game Performance Assessment Instrument. The results showed significant influence of cognitive anxiety (R² =.20; p = .001), somatic anxiety (R² = .45; p = .001) and self-confidence about the passing decisionmaking index (R² = .31; p = .001). It was concluded that competitive anxiety can be considered an intervening factor in decisionmaking of the pass of young male soccer players.Keywords: test validity, scaling, elderly, depression

Effects of short term elastic resistance training on muscle mass and strength in untrained older adults : a randomized clinical trial

Background: The current recommendations on resistance training involving older adults have reported an improvement of body composition variables. Despite this, there is a lack of knowledge on how elastic resistance training (ERT) affects the muscle mass in older adults population. The purpose of this study was to determine the effects of a short-term ERT on muscle mass of health and untrained older adults. Methods: Forty older adults were randomized into two groups of 20 individuals each: Control Group (CG = 66.2 ± 6.6 years) and Training Group (TG = 69.1 ± 6.3 years). TG underwent an ERT twice a week during 8 weeks and control group did not receive any specific intervention. The primary outcome was the upper and lower limbs muscle mass, measured by Dual-energy x-ray absorptiometry. The secondary outcomes were knee isokinetic peak torque (PT) at 60°/s and 120°/s speeds and isometric handgrip strength. A 2×2 mixed model (group [TG and CG] × time [pre and post]) analysis of variance (ANOVA) was applied to determine the effect on primary and secondary outcomes. Results: The results of the ANOVA showed no significant effects in group x time interaction for (1) upper limbs fat free mass (F [1.38] = 1.80, p = 0.19, effect size [ES] = 0.1) and for (2) lower limbs fat free mass (F [1.38] = 0.03, p = 0.88, ES = 0.02). Regarding muscle strength, the ANOVA showed no significant effects in group x time interaction for (3) PT at 60°/s (F [1.38] = 0.33, p = 0.56, ES = 3.0), for (4) PT at 120°/s (F [1.38] = 0.80, p = 0.38, ES = 4.1) and for handgrip strength (F [1.38] = 0.65, p = 0.42-value, ES = 0.9). Analysis of PT in TG showed a significant change of 4.5 %, but only at 120°/s (p = 0.01) when comparing pre and post-training (time interaction). Conclusions: Eight weeks of ERT did not show significant changes in muscle mass and strength of untrained older adults

Bone mineral density and content in adolescent girls.

The aim of the present study was to characterize bone mineral density (BMD) and content (BMC) in Brazilian adolescent girls according to age and pubertal stage. A total of 329 girls ranging in age from 10 to 20 years participated in this study. Body weight, height, body mass index, pubertal stage, race, daily calcium intake, and time spent per week performing moderate to vigorous-intensity physical activity (MVPA) were evaluated. Lumbar spine and femoral neck BMD and BMC were assessed by dual-energy x-ray absorptiometry. One-way ANOVA with Tukey post-hoc test was used to identify differences in bone mass between ages and pubertal stages (p≤0.05). The daily calcium intake reported by the adolescents was inadequate, corresponding to only 26-47% of the recommended allowance (1,300 mg/day). On the other hand, weekly MVPA was higher than that recommended for adolescents. Significant differences in BMD and BMC were observed for girls aged 10-14 years. In addition, lumbar spine and femoral neck BMD was 58 and 31% higher in postpubertal girls, respectively, when compared to prepubertal adolescents

Densidade mineral óssea associada a características físicas e estilo de vida em adolescentes

INTRODUÇÃO: No Brasil, ainda são poucos os estudos que apresentam dados relevantes sobre fatores relacionados às características físicas ou estilo de vida e a densidade mineral óssea (DMO) de adolescentes do sexo feminino. OBJETIVO: Identificar e verificar a contribuição das características físicas e de estilo de vida relacionadas à DMO de adolescentes do sexo feminino. MÉTODOS: A amostra deste estudo foi composta por 329 meninas com idades entre 10 e 20 anos. Como características físicas, foram avaliados: peso corporal, estatura, índice de massa corporal, estágio de maturação sexual, raça e pigmentação cutânea. Já para o estilo de vida, os seguintes fatores foram avaliados: consumo diário de cálcio, nível de atividade física (NAF) e nível socioeconômico (NSE). A densidade mineral óssea (DMO) do corpo inteiro, da coluna lombar e do colo do fêmur foram avaliados pela densitometria óssea. As relações existentes entre variáveis dependentes e independentes foram avaliadas pela correlação de Pearson (r) e regressão múltipla Stepwise (p < 0,05). RESULTADOS: A DMO dos três sítios ósseos tende a aumentar conforme o aumento do peso corporal, estatura, IMC, idade e estágio de maturação sexual (r ≥ 0,43; p < 0,01). Por outro lado, somente o NAF (r = 0,12; p < 0,05) e o NSE (r = 0,14; p < 0,05) correlacionaram-se positivamente com a DMO. O peso corporal, estágio de maturação sexual, idade, consumo de cálcio, NSE e NAF explicaram de 48 a 68% da variação da DMO das adolescentes. CONCLUSÃO: Os resultados sugerem que a utilização de critérios como peso corporal, idade e maturação sexual sejam os mais indicados para controlar as variações da DMO de adolescentes do sexo feminino. Além disso, o NSE, o NAF e o consumo diário de cálcio possuem uma pequena participação na variação da DMO das adolescentes quando comparados com as características físicas

Trace elements influence on bone mineral density in elderly women

To compare trace elements (TE) levels according to bone mineral density (BMD) in elderly women. 27 elderly women (65.7 ± 3.96 years) were evaluated. They were classified in two groups: high BMD (group 1) and low BMD (group 2). BMD was measured in DXA and TE were evaluated from hair sample. Higher levels of Ca, K, Na, Mo, B, Cu e Mg were found in group 1 (high BMD) while Se and Pb were higher concentrated in group 2 (low BMD). The results suggest that the imbalance in the homeostasis of ET may be a risk factor for reduced BMD and higher Pb and Se concentrations can mark bone mass loss

Effect of Competitive Anxiety on Passing Decision-Making in Under-17 Soccer Players

Abstract It is not known if competitive anxiety affects decision-making performance in athletes. This study aimed to analyze the effect of competitive anxiety on passing decision-making in young soccer players. This is a prospective study, whose sample consisted of 40 soccer athletes of the under-17 category. The Portuguese version of the Competitive State Anxiety Inventory (CSAI-2R) was filled out by athletes 45 minutes before the start of a soccer match. Decision-making was evaluated in a real game situation. The analysis and categorization of actions were based on the Game Performance Assessment Instrument. The results showed significant influence of cognitive anxiety (R² =.20; p = .001), somatic anxiety (R² = .45; p = .001) and self-confidence about the passing decision-making index (R² = .31; p = .001). It was concluded that competitive anxiety can be considered an intervening factor in decision-making of the pass of young male soccer players.Keywords: test validity, scaling, elderly, depressio