Systemic changes in body structure of 17-18-year-old schoolboys.

The purpose of this study was to assess the systemic structural changes in the body build of 17-18-year-old schoolboys in the final years of Tartu secondary schools within a height-weight classification dividing anthropometric variables into 5 SD-classes. Weight and height, 9 length, 8 breadth and 2 depth measurements, 16 circumferences and 12 skinfolds were measured. From these 5 length measurements and 53 indices were computed, which characterise the ratios of various parts of the body to body height, to upper and lower limbs' length and body composition. The subjects (n = 253) were divided into five standard deviation classes according to height and weight (Kaarma 1981, 1995). In the first three classes height and weight were proportional: (1) small height--small weight, (2) medium height--medium weight and (3) big height--big weight. In the fourth and the fifth class height and weight were non-proportional. In the fourth class weight was preponderant over height, and in the fifth class height was preponderant over weight. It was proved that a statistical difference exists between the opposite classes--the fourth and the fifth class. It was also revealed that the three proportional classes differ from each other significantly. Increase in body height and weight leads also to an increase in length, breadth and depth measurements, bone thicknesses, circumferences and skinfolds. Rohrer index, body mass index, total percentage of fat by Siri, absolute and relative mass of fat tissue increased from the small to the large class. The relationship of the length, width, and depth measurements, circumferences and bone thicknesses to height remains almost unchanged throughout the proportional classes. These investigations support the position that the whole body model may be reconstructed from body height and weight.

[Features of body structure of Estonian young girls and boys]. / Osobennosti teloslozheniia u Estonskikh devushek i iunoshei.

Anthropometric investigation of 670 female students (aged 18-22), 1114 schoolgirls (aged 15-18) and 253 schoolboys (aged 17-18) has demonstrated that the body structure in these samples formed a distinctive system of significantly intercorrelated variables with the body mass and length being the major characteristics. By means of a mass-length (height-weight) classification it is possible to systematize all the single parameters, indices and body composition characteristics. Body mass and length are also assumed as a basis for the formation of extreme pure somatotypes--pycnic and leptosomatic females.

[Effect of triathlon competition on the content of various hormones and the energy substrate of the blood]. / Vliianie zaniatii triatlonom na soderzhanie nekotorykh gormonov i na énergeticheskie substraty v krovi.

The effect of triathlon (3.8 km swimming, 180 km biking, 42 km running) and of its short variant (1.5 km swimming, 42 km biking, 14 km running) was studied in 7 and 14 well-trained men, respectively. The level of plasma glucose, total cholesterol, HDL, LDL did not change significantly during the competition. FFA concentration increased significantly (by 439 and 61%, respectively). Triglycerides concentration decreased during the prolonged variant. Both variants of triathlon caused a pronounced rise in the cortisol level and moderate increase in somatotropin and progesterone levels. Testosterone concentration increased during a short variant and decreased during a prolonged one. Insulin and C-peptide levels decreased. All those changes in hormones concentration are consistent with an increased lipolytic activity and, may be, with increased glycolytic activity (maintenance of the normal glucose concentration in blood). The rise in the aldosterone level reflects the homeostatic activity in maintaining electrolyte balance.