Risk of low energy availability among female and male elite runners competing at the 26th European cross-country championships

Low energy availability (LEA) causes impaired physiological functioning. Cross-country running is a weight-sensitive sport, making athletes more prone to LEA. We aimed to estimate the prevalence of elite European cross-country athletes at risk of LEA using the LEA in Females Questionnaire (LEAF-Q) and to analyze demographic and physical characteristics that are associated with LEA. Athletes ≥ 18 years competing at the 26th European Cross-Country Championships (n = 602) were invited to complete a questionnaire (sociodemographic, training, anthropometric characteristics, and LEAF-Q). A total of 207 valid surveys were collected (83 females, 22.1 (4.0) years, and 124 males, 22.3 (4.1) years), and 16 surveys were excluded. A high prevalence of athletes at risk of LEA (64.3%) was observed, being higher in females than in males (79.5 and 54.0% respectively, p < 0.001). More than half of athletes (54.1%, n = 112) reported bowel movements once a week or more rarely, while 33 female athletes (41.3%) did not report normal menstruation. Overall, cross-country athletes are at high risk of LEA. Moreover, a high prevalence of gastrointestinal and menstrual impairments was reported. Hence, athletes should be followed by multidisciplinary teams to inform, prevent, and treat LEA and its effects.publishersversionpublishe

Variabilidade biológica da composição corporal humana : implicações nas áreas de investigação das regras e metodologia

Doutoramento em Motricidade Humana na especialidade de Saúde e Condição FísicaThis thesis presents five investigations related to the body composition rules and methodology research areas. In the rules, newly developed methods such as in vivo neutron activation analysis are used as the reference to evaluate the assumption of the stable mineral-to-protein density in Siri's three-compartment model for estimating total-body-fat mass. In the methodology area, the assessment of extracellular water (ECW) with a dilution method and whole-body counting showed significant differences in the fluid distribution-age relations among race groups, with the largest age-related differences observed in African American subjects. In addiction, normative values using a recently developed statistical technique for testing the significance of conditioning variables to generate equations for the 10th, 25th, 50th, 75th and 90th percentiles of ECW were developed. The remaining investigations deal with the evaluation and calibration of body composition methods. Hence,widely used methods, such as dual-energy x-ray absorptiometry (DXA) and air displacement plethysmography in fat mass assessment, were compared with a reference multicompartmental molecular model in a adolescent athletic population. Finally, calibration models were developed for bone mineral content, lean soft tissue, and fat mass filling a methodological gap in the DXA system when subjects taller than DXA scan area need to be evaluated.Esta tese apresenta cinco investigações originais relacionadas com duas áreas de investigação em composição corporal (CC), regras e métodos. Na área das regras, foram usados como referência métodos recentemente desenvolvidos como a activação de neutrões in vivo para avaliar o pressuposto da estabilidade da razão densidade mineral-proteína no modelo a três-compartimentos desenvolvido por Siri para estimar a massa gorda (MG). Neste âmbito foram desenvolvidos novos modelos mecanicistas. Na área metodológica, através da estimação da água-extracelular (AEC) com um método de diluição e contagem do potássio corporal observaram-se diferenças na AEC com a idade em diferentes raças, com maior expansão nos Afro-Americanos. Foram desenvolvidos valores de referência para a AEC através do desenvolvimento de equações para os percentis 10º, 25º,50º, 75º e 90º. As restantes investigações centraram-se na avaliação e calibração de métodos de avaliação da CC. A densitometria radiológica de dupla-energia (DXA) e pletismografia por deslocamento de ar na estimação da MG foram comparados com um método de referência molecular multicompartimental em atletas adolescentes. Finalmente, foram desenvolvidos modelos de calibração para o conteúdo mineral ósseo, tecidos moles magros e MG, preenchendo uma lacuna metodológica na utilização do DXA quando sujeitos mais altos do que a área de scan são avaliados.FCT;FS

Changes in Phase Angle and Handgrip Strength Induced by Suspension Training in Older Women

This study aimed to present a suspension exercise training program suitable for older adults and to verify the effect of 12 weeks of training on handgrip strength (HS) and anthropometric and bioelectrical impedance parameters in older adults. Thirty older women (age 66.1±4.7 years, BMI 30.6±5.3 kg/m2) were randomly assigned to one of two groups: a training group (TG, n=15) or a control group (CG, n=15). The TG participated in a 12-week suspension training program, while the CG maintained their normal physical activity habits for the duration of the study. Anthropometric, bioelectrical impedance and strength parameters were evaluated before and after the intervention period. There was a significant group by time interaction (p<0.05) for triceps, biceps, subscapular skinfold, percentage of fat mass, phase angle (PhA), resistance, reactance, specific resistance, specific reactance and HS, with significant improvements in the TG after the intervention period (p<0.05) even after adjusting for age and BMI. The results suggest that suspension training promotes increases in PhA and HS in older women

Association between Phase Angle and Body Composition of Children and Adolescents Diagnosed with HIV Infection

The aim of the study was to investigate how phase angle (PhA) is associated with subtotal and lumbar spine bone mineral density [BMD], lean soft tissue mass [LSTM], total body fat mass, android and gynoid in children and adolescents with HIV according to sex. A cross-sectional study was conducted in Florianópolis, Brazil, involving 64 children and adolescents vertically transmitted with HIV. Resistance and reactance values were obtained using bioelectrical impedance analysis, and PhA was subsequently calculated. Dual emission X-ray absorptiometry was used to assess body composition. Antiretroviral medication, physical activity (accelerometers) and skeletal maturation (wrist-carpal radiography) were used in the adjusted model. In males, PhA was directly associated with subtotal BMD (βadj: 0.65; R²: 0.38, p p = 0.01), directly associated with LSTM (βadj: 0.76; R²: 0.46, p p = 0.01), in adjusted models. In females, PhA was directly associated with subtotal BMD (βadj: 0.46; R²: 0.17, p p < 0.01). It is concluded that PhA was directly associated with subtotal and regional BMD, LSTM, and inversely with gynoid fat in boys with HIV. In girls, PA was directly associated only with subtotal and regional BMD

Análise de equações preditivas da gordura corporal em jovens atletas de "taekwondo"

Due to the lack of valid and accessible tests to measure the body fat percentage (BF%) of adolescent taekwondo athletes (TKDA), this study aimed to analyze six anthropometric equations in the prediction of BF% with the Dual-Energy-x-Ray (DEXA) as referential method for five TKDA (12.23 years ± 1.60). The BF% estimated by the equations were compared with DEXA values using the t-student , linear regression and Bland & Altman (B&A) tests. Only the equation of Slaughter et al. (1988) was adequated by the sample size calculation, and although it subestimated the BF% (in 4.85% ± 0.98), it showed a high correlation (R = 0.935; R² = 0.874 EPE = 1.01) and low amplitude in the limits of agreement at 95% (3.84%) by B&A in comparison to DEXA. However, this equation is adequated to predict the BF% in TKDA, if it's corrected by the adjustement equation [%G (DEXA) = 1,64 + 1,24&#8226;%G (Eq 4)] generated by linear regression.Debido a la falta de métodos accesibles válidos para medir el porcentaje de grasa del cuerpo (%G) de atletas de taekwondo adolescentes (TKDA), destinada a analizar seis ecuaciones antropométricas de predicción de %G, en cinco TKDA (12,23 años ± 1,60 ), utilizando como método de referencia la Densitometría Radiológica de Energía Dual (DEXA). El %G estimado por las ecuaciones fue comparado mediante la prueba t-student, regresión lineal y Bland & Altman (B&A) con los que se obtienen mediante DEXA. Sólo la ecuación del SLAUGHTER et al. (1988) fue adecuada para el cálculo del tamaño de la muestra y, a pesar de que había subestimado la %G (4,85 % ± 0,98 ), este mostró una alta correlación (R = 0,935 ; R2 = 0,874 EPE = 1,01 ) y baja amplitud dentro de los límites de concordancia con el 95% (3,84 %) por B&A en comparación con la DEXA. Por lo tanto, esta ecuación demostró ser adecuada para la predicción de %G en TKDA, desde que corrigida mediante la siguiente ecuación de ajuste [ %G (DEXA) = 1,64 + 1,24 &#8226; %G (eq 4)] generada mediante regresión lineal.Devido à falta de métodos acessíveis válidos para mensurar o percentual de gordura corporal (%G) de taekwondistas adolescentes (TKDA), objetivou-se analisar seis equações antropométricas de predição do %G, em cinco TKDA (12,23 anos ± 1,60), utilizando como método de referência a Densitometria Radiológica de Dupla Energia (DEXA). Os %G estimados pelas equações foram comparados pelo teste t-student, regressão linear e Bland e Altman (B&A) com os obtidos por DEXA. Apenas a equação de Slaughter et al. (1988) foi adequada pelo cálculo amostral, e embora tenha subestimado o %G (em 4,85% ± 0,98), esta apresentou alta correlação (R = 0,935; R² = 0,874 EPE = 1,01) e baixa amplitude nos limites de concordância a 95% (3,84%) pelo B&A em comparação com a DEXA. Portanto, esta equação mostrou-se adequada para a predição do %G em TKDA, desde que seja corrigida pela equação de ajuste [%G (DEXA) = 1,64 + 1,24 &#8226; %G (Eq 4)] gerada pela regressão linear

Determinant factors of cardiorespiratory fitness in Portuguese adolescents of different ethnicities.

Cardiorespiratory fitness is an important health indicator in young people. The aim of this study was to investigate the effects of age, gender, body adiposity, and ethnicity on cardiorespiratory fitness in a sample of Portuguese adolescents. The sample consisted of 266 adolescents aged 12-18 years [112 boys (80 Caucasians and 32 African-Portuguese, AP) and 154 girls (109 Caucasians and 45 AP)]. Percent body fat was estimated with a hand-to-hand bioelectrical impedance device (BF300, OMROM). Cardiorespiratory fitness was assessed by a shuttle run test (Fitnessgram battery). Multiple regression models were used for statistical analysis. The results showed that girls presented lower maximal oxygen consumption and higher percent body fat than boys. Cardiorespiratory fitness was lower in Caucasian than in AP girls. Multiple regression analysis showed that percent body fat, age and the interaction of age with being Caucasian and age with female gender were significant determinants that were negatively associated with cardiorespiratory fitness. The results suggest that maximal oxygen consumption is lower in adolescents with higher adiposity and in older adolescents. The findings highlight the importance of promoting physical fitness in schools across ages, especially in older adolescents, adjusting for determinant factors such as gender and ethnicit

<b>Determinant factors of cardiorespiratory fitness in Portuguese adolescents of different ethnicities</b>. DOI: 10.5007/1980-0037.2011v13n4p243

Cardiorespiratory fitness is an important health indicator in young people. The aim of this study was to investigate the effects of age, gender, body adiposity, and ethnicity on cardiorespiratory fitness in a sample of Portuguese adolescents. The sample consisted of 266 adolescents aged 12-18 years [112 boys (80 Caucasians and 32 African-Portuguese, AP) and 154 girls (109 Caucasians and 45 AP)]. Percent body fat was estimated with a hand-to-hand bioelectrical impedance device (BF300, OMROM). Cardiorespiratory fitness was assessed by a shuttle run test (Fitnessgram battery). Multiple regression models were used for statistical analysis. The results showed that girls presented lower maximal oxygen consumption and higher percent body fat than boys. Cardiorespiratory fitness was lower in Caucasian than in AP girls. Multiple regression analysis showed that percent body fat, age and the interaction of age with being Caucasian and age with female gender were significant determinants that were negatively associated with cardiorespiratory fitness. The results suggest that maximal oxygen consumption is lower in adolescents with higher adiposity and in older adolescents. The findings highlight the importance of promoting physical fitness in schools across ages, especially in older adolescents, adjusting for determinant factors such as gender and ethnicit

Accuracy of anthropometric measurements in estimating fat mass in individuals with 21-hydroxylase deficiency

Objective: the use of anthropometric measurements to estimate the percentage of body fat (%BF) is easy and inexpensive. However, the accuracy of these methods in patients with 21-hydroxylase deficiency (21OHD) has not been explored. the objective of this study was to evaluate the accuracy of skinfold-based models, body mass index (BMI), and waist circumference (WC) in estimations of %BF using dual-energy X-ray absorptiometry (DXA) as the reference method in individuals with 21OHD.Methods: Fifty-four 21OHD patients (32 women and 22 men), aged 7 to 20 y, were recruited for the study. DXA was used to determine %BF; four predictive skinfold equations, BMI, and WC were assessed for accuracy in determining %BF.Results: All predictive skinfold equations were highly associated (R, range: 0.82-0.89) with DXA %BF values. in women, BMI and WC showed moderate correlations (R = 0.69 for both BMI and WC) with DXA values. in contrast, among men there was a low explanatory power for BMI (13%) and WC (4%) and high errors (BMI, 6.9%; WC, 7.4%). All predictive equations significantly underestimated %BF (range of differences, -4.1 to -8.9) compared with DXA (women, 31.3 +/- 6.1; men, 24.4 +/- 7.3), and large limits of agreement were observed (range, -15.3 to 1.7 and -15.5 to 4.2 for women and men, respectively).Conclusion: in children and adolescents with 21OHD, %BF as estimated by skinfold measurements was associated more strongly with DXA-assessed %BF than both BMI and WC. However, still, the skinfold-based assessment underestimated DXA %BF and showed moderate agreement (C) 2012 Elsevier Inc. All rights reserved