The Relationship Between the Accuracy of Certain Generalized Body Density Prediction Equations and Indices of Fatness, Body Physique/Proportionality and Fat Distribution.

There is a need to eliminate the least accurate of the existing equations for anthropometrical body density prediction and support for the use of specific prediction equations over generalized equations. The purpose of the investigation was to examine the accuracy of the Jackson-Pollock (JP) and Durnin-Womersley (DW) generalized anthropometrical body density prediction equations in relation to indices of overall fatness, regional fat distribution and body proportionality. The relationships between prediction accuracy (predicted body density minus hydrodensitometric estimate of body density) and three mass/stature indices (total fatness indices), waist-to-hip circumference ratio (WC/HC)(android/gynoid fat distribution) and the three components of the Heath-Carter somatotype (body proportionality) were examined. if the prediction equations were truly generalized , no relationship between prediction accuracy and any of these indices should exist, rather accuracy should be random across the range of any index. Forty-five Caucasian males were recruited so that they were all similar with respect to age and overall adiposity to those subjects from which the JP and DW equations were derived. Results revealed no relationship (p $\u3e$ 0.05) between JP accuracy and any of the fatness indices, WC/HC or the somatotype. Similar results were found to exist with regards to the DW accuracy relationship with the fatness indices and WC/HC (p $\u3e$ 0.05). The accuracy of the DW equation was found to be significantly (p $\le$ 0.05) related to the components of the somatotype. The accuracy of the DW equation changed significantly as the components of the somatotype changed. Based on these results, it appears that the JP equation is accurate for generalized use across total adiposity as reflected by the mass/stature indices, regional fat distribution as reflected by WC/HC and body proportionality as reflected by the somatotype. The DW equation also appears to be accurate for generalized use across the total fatness and regional fatness indices. However, the DW equation is not generalized across a range of body proportionalities and its use as a generalized prediction equation is not recommended on a sample that varies from the original derivation sample with respect to body proportionality

Body composition and the brain: investigating life history trade-offs in living humans

The ‘expensive-tissue’ hypothesis of Aiello and Wheeler is well-known in anthropology for positing that an increasingly small gut was a key factor in the evolution of the large hominin brain. The insight that organs and tissues in the body compete for energy resources was also central to the ‘thrifty phenotype’ hypothesis of Hales and Barker, which proposed that nutritional stress in fetal life resulted in differential growth of the brain and pancreas. Both hypotheses are consistent with life history theory, which assumes that energy allocation trade-offs occur in energylimited environments. The prediction that somatic traits trade off against one another in the context of the body’s fixed energy budget has, however, yet to be rigorously tested in humans. The current thesis project aimed to fill this gap by recruiting 70 healthy young women and obtaining comprehensive, high-quality data on their brain and body composition. This included, specifically, measures of brain gray and white matter volume, fat mass, skeletal muscle mass, and volumes of the heart, liver, kidneys and spleen. Additional outcomes included resting energy expenditure and two proxies of early-life growth: birth weight, a marker of fetal weight gain, and tibia length, a marker of linear growth indexing postnatal experience. With these data, three principal hypotheses were tested: 1) there is variation in the energy expenditure of tissues and organs; 2) trade-offs are observed between brain and body organs/tissues; and 3) trade-off relationships are mediated by early-life growth. Results suggest the metabolic cost of organs and tissues is variable, and that the brain – in particular its gray matter component – trades off against lean tissues in the body (i.e. skeletal muscle, the liver and kidneys), but not fat mass. However, less support was found for the prediction that trade-offs are mediated by fetal and infant growth

Cineantropometría: composición corporal y somatotipo de futbolistas que desarrollan su actividad física en equipos de la Comunidad Autónoma de Madrid

Definimos Cineantropometría como el estudio del tamaño, forma, proporcionalidad, composición, maduración biológica y función corporal; con objeto de entender el proceso del crecimiento, el ejercicio, el rendimiento deportivo y la nutrición. OBJETIVOS: Estudio controlado, transversal, no randomizado, de tipo observacional y analítico cineantropométrico. MATERIAL Y METODO: Utilizamos el protocolo de medidas establecido por la Sociedad Internacional para el Avance de la Cineantropometría (I.S.A.K.) y aceptadas por el Grupo Español de Cineantropometría. RESULTADOS: La talla media de todos los jugadores estudiados es de 176.64 cm; peso 77.01Kg, porcentaje de grasa derecho 8.04% e izquierdo 8.10%, masa ósea derecha 11.72Kg e izquierda 11.59Kg, masa muscular derecha 38.46Kg e izquierda 38.55Kg, peso residual 18.56Kg, somatotipo derecho e izquierdo Endo - Mesomorfo. CONCLUSIONES: 1. La homogeneidad interpoblacional aparece como un rasgo característico general de los jugadores de fútbol investigados, patente cuando los analizamos por categoría profesional, pero existe cierta heterogeneidad al distinguirlos en base a su posición en el terreno de juego. 2. La heterogeneidad intrapoblacional aparece como rasgo específico manifestado en los porteros, futbolistas que muestran una tipología propia cuando se analizan por su posición en el terreno de juego, desarrollando un morfotipo característico, siendo los futbolistas más altos y pesados. 3. La talla es superior en los jugadores de fútbol profesionales, lo que no corresponde a un mayor peso. Los futbolistas de la 2ªB división son los deportistas más bajos y asimismo los más ligeros. 4. Los jugadores de fútbol más altos y más pesados son los porteros no profesionales, y los delanteros de la 2ªB división los más bajos y livianos. 5. Los somatotipos no valoran la asimetría, pero registran información de la diferencia entre el lado derecho y el izquierdo en estudios particulares. 6. La heterogeneidad intragrupo reafirma nuestro objetivo de estudiar a los jugadores de fútbol como dos hemimitades independientes. La variabilidad entre el hemicuerpo derecho e izquierdo expuesta en las conclusiones precedentes no cuestiona en ningún momento la aceptación universalmente aprobada y base del método científico utilizado en la presente investigación de considerar las mediciones realizadas en el lado derecho equivalentes al futbolista en su conjunto