RESUMO
Purpose: The purpose of this study was to examine the relationship among helmet surface temperature (Thl), head top temperature (Thd) and tympanic temperature (Tty) during American football practice in summer. Methods : The subjects were collegiate American football players. Temperatures were measured in August in 1993 and 1994. Thl, Thd and Tty were measured by infrared tympanic thermometers. Environmental temperatures that were measured were dry-bulb temperature (Td), wet-bulb temperature (Tw), globe temperature (GT) and wet-bulb globe temperature (WBGT) . Results: Significant correlations were observed among all measured temperatures (P<0.0001) . High coefficients of correlation were observed among Thl, Thd and GT. The highest relationships were observed between Thl and Thd (r=.727), and between Tty and Td (r=.766) . The coefficient of correlation between Tty and Thl was higher than that between Tty and Thd. Heat stress of the whole body (F1; heat stress factor: Tty, Td, Tw and WBGT, proportion=71.4%) and head environment factor (F2 ; helmet factor : Thl, Thd and GT, proportion=14.3%) were chosen in factor analysis. A close relationship was observed between both factors (r=.773) . Both GT and Thl showed a high correlation with Thd, which suggests the influence of radiant heat through a helmet on the whole body. Conclusion : The temperature in a helmet is a micro environment temperature surrounding the head. Accordingly, the heat load is reduced by taking the helmet off frequently during football practice.
RESUMO
Anthropometric measurements were obtained on 126 male nonathletic first year university students (N-1), 178 male nonathletic third year university students (N-3) and 114 male athletic third year university students (A) . The mean values of height and body weight for group A were significantly larger than those for groups N-1 and N-3. Group A showed significant larger mean values of girth of chest, abdomen, thigh and upper arm than groups N-1 and N-3. Physical status of group N-1 was a little shorter and slender than that of group N-3. Group A showed significantly greater mean values of Rohrer's index and Brugsch's index than groups N-1 and N-3. The mean values of skinfold thickness and body fat (%) caluculated by using prediction formula from mean skinfold thickness for group A were significantly smaller than those for group N-3 and were essentially the same as those for group N-1. Bigger physique and smaller body fat content of athletes could be explained as due to a result of physical training and might be considered as the cause of superior physical fitness of athletes.<BR>The following prediction equations for standard body weight (W) from height (H) using mean values of body weight and height (W and H) and their standard deviations (cW and aH) are proposed for the evaluation of overweight and underweight.<BR>W=3W/HH-2W<BR>and W=σW/σHH-σW/σHH+W<BR>Plotting of body weight and body fat content in standard measure against height in standard measure was used to compare physical characteristics of athletes with those of nonathletes.
RESUMO
Anthropometrical measurement were obtained on 178 male nonathletic university students and 168 male athletic university students (Swimming, Handball, Soccer, Rugby, Running, Thrower, Judo and Gymnastics) aged 18-22 years.<BR>The results obtained were as follows<BR>The mean values of height and body weight for nonathletes were 170.2cm and 59.7kg respectively. The mean values of height and body weight for athletes except gymnastics and long distance runner were larger than those for nonathletes. Athletes showed larger mean values of girth of chest than nonathletes (86.1cm) . The mean values of girth of upper arm and girth of thigh for nonathletes were 26.9cm and 50.6cm respectively. The mean values of girth of upper arm for athletes except basketball, long distance runner and jumper were considerably larger than that for nonathletes. Athletes except long distance runner, jumper and gymnastics showed larger mean values of thigh than nonathletes. The mean values of skinfold thickness for athletes except heavy weight class of judo were thinner than that for nonathletes and the percentage of body fat calculated by using the prediction formura from mean skinfold thickness, body surface area and body weight for athletes was smaller than that for nonathletes<BR>Plotting of body weight and body fat content in standard measure against height in standard measure with family of iso-deviation line was used to compare the body composition and body shape of athletes with those of nonathletes. In this plotting, physical characteristics could be expressed as the difference (R) between the points representing the mean value of athletes on the origin, (the mean values of nonathletes) and ratio of deviation (r) from standard line representing correlation of body weight or body fat content to height for nonathletes. Plotting R against r with family of lines of the same height was proposed to differentiate physical characteristics of athletes participating in different kinds of sports and to evaluate the effect of training on physical characteristics. Plotting of girth of upper arm and girth of thigh in standard measure against girth of chest was used for the evaluation of difference in body shape of athletes.