Positive association of lean mass and negative association of protein intake on bone mass and bone geometry of adolescent soccer players.

OBJECTIVE: The aim of this study was to evaluate the association of food consumption and body composition on bone parameters in adolescent soccer players. METHODS: There were 148 male soccer players 12 to 18 y who participated in the study. Body composition was assessed by dual energy x-ray absorptiometry, comprising bone mineral density (BMD) and bone mineral content (BMC) of total body without head (TBLH), lumbar spine (L1-L4), and right femoral neck (RFN). The bone geometry variables measured were femoral strength index (FSI), buckling ratio (BR), section modulus (Z), cross-sectional moment of inertia (CSMI), and cross-sectional area (CSA). Food intake was analyzed using the 24-h food recall. Somatic maturation was estimated by the peak height velocity equation. For the statistical analysis, the stepwise multiple linear regression was used, with P < 0.05. RESULTS: Regarding food consumption, there was a high protein intake and low calcium intake. Lean mass was a predictor of BMC of TBLH (R2 = 0.524), L1-L4 (R2 = 0.492), and RFN (R2 = 0.405); BMD of L1-L4 (R2 = 0.407) and RFN (R2 = 0.27); Z (R2 = 0.683), CSMI (R2 = 0.630), and CSA (R2 = 0.640). There was a negative correlation between protein intake with bone mass and bone geometry parameters. CONCLUSION: In adolescent soccer players, lean mass was a predictor of bone parameters, and high protein intake was negatively associated with bone mass and geometry.

Effect of 7 Months of Physical Training and Military Routine on the Bone Mass of Young Adults.

INTRODUCTION: Physical activity (PA) has a great influence on bone mineral density (BMD) and bone mineral content (BMC), however longitudinal studies that seek to relate bone mass to physical activity are scarce and have a small sample size. The aim of this study was to evaluate and compare the effect of 7 months of military physical training (MPT), impact sports (IS), and swimming in the bone mass of young military adults. MATERIALS AND METHODS: A prospective study was conducted with 213 military school students (male and aged 19.2 ± 1.2 years) divided into three groups: MPT (n = 144), IS (n = 56), and Swimming (n = 13). Dual-energy X-ray absorptiometry was used to determine body composition (percentage of fat, fat mass, and fat-free mass) and bone mass (BMD, BMD Z-Score, total BMC, arm BMC, leg BMC, and trunk BMC), at the beginning of the military service and after 7 months of training. RESULTS: It was observed a significant increase in BMD, BMD Z-Score, total BMC and BMC of all segments analyzed for all groups (p < 0.01). There was a significantly greater variation in BMD of the IS group in relation to the MPT group (p < 0.01), and in the arm BMC of the MPT group in relation to the IS group (p < 0.05). CONCLUSION: After 7 months of training, there were significant increases in BMC and BMD of all the groups evaluated. The bone response was associated with the muscular group used in the physical exercise and the IS group showed greater gain in BMD.

Can anthropometric, body composition, and bone variables be considered risk factors for musculoskeletal injuries in Brazilian military students?

BACKGROUND: Musculoskeletal injuries are the main cause of premature discharge from military service and can sometimes lead to permanent disabilities. Some intrinsic risk factors are well discussed in the literature. However, the relation between body composition variables and the risk for musculoskeletal injury is not well known or recognized. METHODS: This prospective study evaluated 205 Brazilian military students. At the beginning of military service, health status and sports experience prior to military service were registered. Anthropometric variables were evaluated, and bone and body composition variables were measured using dual-energy X-ray absorptiometry. The occurrence of musculoskeletal injuries throughout the year was registered at the military physiotherapy service. At the end of 1 year of follow-up, risk factors were analysed by comparing the variables between the injured and non-injured students. RESULTS: No difference in previous health status was found between injured and non-injured groups, whereas sports experience prior to military service was identified as a protective factor (Odds Ratio (OR) 0.323; 95% CI: 0.108-0.968; p = 0.044). Anthropometric, bone, and body composition variables could not be identified as risk factors for musculoskeletal injuries in Brazilian military students. CONCLUSION: Anthropometric, bone, and body composition variables could not be considered risk factors for musculoskeletal injuries in Brazilian military students.

Dual-energy x-ray absorptiometry metabolic maps to resting energy expenditure estimation, and body size dependence in Brazilian young men.

OBJECTIVES: The model most suitable for estimating resting energy expenditure (REE) using dual-energy X-ray absorptiometry (DXA) metabolic maps is not known; moreover, the applicability in individuals with different body sizes also is uncertain. The aim of this study was to test the accuracy of REE estimation from models of DXA metabolic maps with four, five, and six tissue-organ components in young men, stratified by body size. METHODS: We studied 52 young men between the ages of 18 and 29 y. Participants were clustered to small (SW; n = 32) and large (LW; n = 20) weight, and small (SWH; n = 25) and large (LWH; n = 27) weight-height. REE was measured by indirect calorimetry (REEm), and predicted from DXA metabolic maps with four (REEc1), five (REEc2) and six (REEc3) tissue-organ components. RESULTS: REEc1, REEc2, and REEc3 explained 54% (P < 0.001), 56% (P < 0.001), and 58% (P < 0.001) of REEm variance in all participants, respectively. However, REEc2 showed mean difference between REEm (P < 0.001), and REEc3 showed trends in estimating the REE (P < 0.05). In contrast, REEc1 showed limits of agreement (95%) of -248.3 to 285.8 kcal/d, 18.7 ± 136.3 kcal/d of bias, and no trends in the Bland-Altman analysis. The relationship between all predicted models and measured REE decreased in LW and LWH. CONCLUSIONS: REEc1 can be considered the best accurate model of REE estimation in Brazilian young men, providing the REE and metabolically active tissue-organ of four components. Caution should be exercised with the use of DXA metabolic maps in populations with greater weight and greater weight-height.

Body composition as a frailty marker for the elderly community.

BACKGROUND: Body composition (BC) in the elderly has been associated with diseases and mortality; however, there is a shortage of data on frailty in the elderly. OBJECTIVE: To investigate the association between BC and frailty, and identify BC profiles in nonfrail, prefrail, and frail elderly people. METHODS: A cross-sectional study comprising 235 elderly (142 females and 93 males) aged ≥65 years, from the city of Amparo, State of São Paulo, Brazil, was undertaken. Sociodemographic and cognitive features, comorbidities, medication, frailty, body mass index (BMI), muscle mass, fat mass, bone mass, and fat percent (%) data were evaluated. Aiming to examine the relationship between BC and frailty, the Mann-Whitney and Kruskal-Wallis nonparametric tests were applied. The statistical significance level was P<0.05. RESULTS: The nonfrail elderly showed greater muscle mass and greater bone mass compared with the prefrail and frail ones. The frail elderly had greater fat % than the nonfrail elderly. There was a positive association between grip strength and muscle mass with bone mass (P<0.001), and a negative association between grip strength and fat % (P<0.001). Gait speed was positively associated with fat mass (P=0.038) and fat % (P=0.002). The physical activity level was negatively associated with fat % (P=0.022). The weight loss criterion was positively related to muscle mass (P<0.001), bone mass (P=0.009), fat mass (P=0.018), and BMI (P=0.003). There was a negative association between fatigue and bone mass (P=0.008). DISCUSSION: Frailty in the elderly was characterized by a BC profile/phenotype with lower muscle mass and lower bone mass and with a higher fat %. The BMI was not effective in evaluating the relationship between BC and frailty. The importance of evaluating the fat % was verified when considering the tissue distribution in the elderly BC.

Efeito de 13 semanas de treinamento físico militar sobre a composição corporal e o desempenho físico dos alunos da escola preparatória de cadetes do exército / Effect of 13 weeks of military exercise training on the body composition and physical performance of espcex students

INTRODUÇÃO: Exércitos do mundo inteiro reconhecem a importância de uma boa condição física para o desempenho das funções militares. O treinamento físico militar (TFM) tenta proporcionar auxílio nessa busca por uma melhor condição física e corporal. OBJETIVO: Verificar o efeito de 13 semanas de TFM na composição corporal e no desempenho físico dos alunos da Escola Preparatória de Cadetes do Exército (EsPCEx). MÉTODOS: A amostra foi constituída de 287 alunos do sexo masculino da EsPCEx com idade média de 18,33 ± 1,26 anos. Tais alunos cumpriram uma rotina de internato, com horários, refeições e atividades definidas, da qual eram liberados somente nos finais de semana. O TFM foi realizado numa frequência semanal de cinco dias e englobou treinamentos aeróbicos e resistivos. Foram realizadas no período pré e pós-treinamento medidas da massa corporal, altura, dobras cutâneas (tricipital, abdominal e suprailíaca) e realizados os seguintes testes: corrida de 12 minutos, abdominal parafuso, flexão de braço e flexão na barra fixa. Com os dados antropométricos coletados, foi calculado o percentual de gordura, massa livre de gordura (MLG) e massa gorda (MG) baseado no protocolo de três dobras de Guedes. RESULTADOS: Quando comparados os valores dos dados antropométricos e da composição corporal dos períodos inicial e final de treinamento foi observada redução significativa na MG, no percentual de gordura, nas dobras cutâneas tricipital e abdominal e aumento na dobra cutânea suprailíaca e na MLG. Ocorreram melhoras significativas também em todos os testes físicos realizados, nos quais um melhor desempenho foi alcançado. CONCLUSÃO: Os dados obtidos sugerem melhora significativa na composição corporal e no desempenho físico através da realização do TFM, com frequência semanal de cinco dias.

INTRODUCTION: Armies from all over the world acknowledge the importance of good physical fitness for the performance of military duties. The Military Exercise Training (MET) attempts to provide assistance to this search for better physical fitness and performance. OBJECTIVE: To verifying the effect on the body composition and physical performance of the students at ESPCEX (Military School for Preparation of Army Cadets) after 13 weeks of MET. METHODS: The sample was formed by 287 male students from the ESPCEX, whose average age was 18.33 ±1.26. Such students accomplished a boarding school routine, having defined schedules, meals and activities from which they were only released during the weekends. The MET was accomplished five days a week and it comprised both aerobic and resistance training. Measurement of body mass, height, skinfold (triceps, abdominal and suprailiac) was accomplished during pre and post training periods, and the following tests were performed: 12-minutes-run, oblique sit up, arm push up and pull up. Fat percentage, fat-free body mass and fat body mass were calculated using the anthropometric data based on the Guedes 3 skinfold protocol. RESULTS: Significant reduction in fat body mass, fat percentage and in triceptal and abdominal skinfold, as well as increase in suprailiac skinfold and fat-free body mass was observed when anthropometric and body composition data were compared, during the initial and the final periods of training. Significant improvement also occurred in all prformed physical tests, in which better performance was achieved. CONCLUSION: The acquired data suggest that performance of MET 5 days a week brought significantly improved body composition as well as physical performance.