To study the age difference in sweating during muscular exercise, two series of experiments were conducted under constant climatic conditions (29 ± 1°C DB, 60 ± 5 % RH, 0.45±0.05 m/sec air flow) . In series A, 7 to 20 years old male subjects undertook 5-minute running or pedalling of a bicycle ergometer in various seasons. In this series of experiments, pectoral sweat volume, sweat chloride concentration, rectal and mean skin temperatures were in general determined every 5 minutes and, when necessary, the total body sweat volume was calculated from the body weight loss. In series B, the age difference in the sweating in relation to physical training was studied. Subjects, 3 to 20 years old received experimental physical training of 5-minute or 500m-running. Before and after the training, a work load of 3- or 5-minute outdoor running was assigned to them. Furthermore, before and after the training, 10 and 11 years old subjects were given a fixed mechanical work rate on a bicycle ergometer. In these experiments, most of the parameters described above were measured. In series A, age differences in sweating during exercise were noticed to be dependent on the intensity of work load between pre- and post-adolescents. When the work load was heavy enough to cause a rapid increase in rectal temperature, the sweat volume became significantly less, the mean skin temperature was far higher, and the sweat chloride concentration was remarkably smaller in the pre-adolescent subjects than in the post-adolescent ones. In series B, an age difference in the effect of physical training was also found on sweating during exercise. The effect of physical training on sweating in the pre-adolescent individuals was generally less significant than in adults and sometimes showed a different pattern from that of adults. From these results, it can be concluded that sweating in the pre-adolescents is less adaptive, particularly to continuous severe exercise and that physical training is less effective in them than in the post-adolescents.
The purpose of the present study is to investigate the changes in postural sway (PS) related to age quantitatively. The movement in the center of gravity of the body projected into the base of support was used as a criterion of PS. It was measured in 45 subjects, 23 males and 22 females, ranging in age from 22.1 to 68.1. The subjects maintained erect posture with feet together for about 2 minutes with eyes open, and thereafter with eyes closed respectively. The measurement of PS has been made by measuring the weight at two points of the supporting platform. The degree of PS was calculated by using an electronic computer (HITAC-10-II) . The following results were obtained. 1. The displacements of body's center of gravity per 1 minute with eyes open as well as with eyes closed increased with age. The PS, however, showed a gradual increase with eyes open, and then it did a steep increase with eyes closed from the age of fifties. 2. The PS was reduced to two components, i.e., lateral (X) and antero-posterior (Y) ones. The ratio of the Y component to the X one (Y/X) with eyes open as well as with eyes closed showed a gradual decrease with age. 3. The ratio of X component with eyes closed to that with eyes open was calculated as well as the ratio of Y component. At all ages the ratio in X component was larger than that in Y component. 4. Judging from both the steep increase in PS with eyes closed and the gradual increase with eyes open with age, there seems to exist the modification of static equilibration mechanism in the aged, especially the much degradation of some regulatory function other than visual one.
A number of investigators have been concerned with the anthropometric as well as physical characteristics of sumo wrestlers during the past several decades. However, none have attempted to determine body density and percent body fat by the most accurate technique of hydrostatic or underwater weighings. Thus, a precise quantification of body density and percent body fat for the wrestlers has not yet been obtained. Ogawa et al. (1972) have predicted the body composition of sumo wrestlers from a formula which added the triceps and subscapular skinfold thicknesses. As the regression equation used in this instance was based on samples of normal young men, it may not have great predictive accuracy when used on the exceptional population of very stout athletes. The purposes of this study were : (1) to assess the validity of percent body fat estimation by skinfold thickness measurement when compared to the hydrostatic weighing criterion method ; (2) to determine the interrelationships between anthropometric variables for use in the clear assessment of the physical characteristics of ‘Shindeshi’ sumo wrestlers ; and (3) to thereby develop a formula that would reliably predict percent body fat using skinfold thicknesses and/or anthropometric measurements in this exceptional population. The interrelationships between anthropometric and body composition variables were investigated using 35 Shindeshi sumo wrestlers, aged 15-20 years (X=16.5±1.5) . The results of the present study can be summarized as follows. 1. The Shindeshi in the present study possessed physiques more developed than those tested in the past, as evidenced by Rohrer's and Ponderal Indices which were approximately 180 and 26.2, respectively. The development of body weight was particularly notable (i.e., over 100kg) . 2. Percent body fat for the Shindeshi was remarkably higher than that of a normal population of the same age, with approximately seventy percent of the Shindeshi possessing more than 20% body fat and less than 1.05000 body density. 3. Body density and height correlated negatively and insignificantly with almost all the variables. In contrast, correlations of body weight, circumferences, and all other variables were, in most cases, high and positive, with body weight correlating least with height. The skinfold measurement correlating best with % body fat was that taken at the thigh site (r=0.898) . The circumference measurements correlating best with % body fat were obtained at the thigh (r=0.888 and 0.831) and the abdomen (r=0 885) parts. 4. Of the six formulae for estimating % body fat, Sloan's correlated best with % body fat as determined by densitometry, and best approximated the mean value of 24.5%. However, all of the equations underestimated the measured % body fat of the Shindeshi. 5. When an exceptional population is being investigated, estimation of % body fat should be done with a population specific equation to ensure predictive accuracy. The following multiple regression equation (r=0.963) should, therefore, be utilized for estimation of % body fat in sumo wrestlers. Y=0.2488x1+0.6172x2-14.3962 where x1 and x2 are abdomen circumference and skinfold thickness at thigh, respectively.
34 male rats (13 weeks old) were used in this experiment. 11 rats were at rest and 23 rats were loaded to run on a treadmill with 2 degree slope at a speed of 25m/min. Relation between quantities of blood substances (plasma glycerol, blood lactate and plasma free fatty acids ; FFA) and lipolytic activity of epididymal adipose tissue was studied to clarify a mechanism of lipolysis of the adipose tissue in the exercise. 1) Plasma FFA and glycerol began to increase in parallel at 30 min after the run, but at exhaustion only plasma glycerol enhanced. 2) Blood lactate increased at 10 min after the run and more at exhaustion. 3) Basal lipolytic activity of epididymal adipose tissue in vitro was not influenced by the run, while norepinephrine induced lipolysis of the adipose tissue decreased with lapse of running time. Relation between plasma FFA and lipolytic activity of epididymal adipose tissue was inverse during the run. 4) There was also inverse relation between blood lactate and lipolytic activity of adipose tissue induced with norepinephrine. From these results, it is assumed that the increase of plasma FFA during the exercise was not resulted from the increase of lipolytic activity of the adipose tissue stimulated with only norepinephrine and effects of other hormones (ACTH, Glucagon, Growth hormone and etc.) and their interactions on the lipolysis might be considered.
The effect of endurance training on aerobic power and the relationship between aerobic power and running performance were investigated longi tudinally on eleven junior runners for 5-7 years, starting from the age of 14, 15 yr. Maximal aerobic power was measured with the subject running on a motor-driven treadmill. The subjects were divided into two groups (Group I, II) . The results were as follows ; 1) Group I (superior junior runners) showed greater aerobic power and better running performance compared to Group II (good junior runners) . The values for Group II were between those for Group I and for ordinary school boys. 2) Aerobic power for Group I increased from 14, 15 to 18, 19 years old, while aerobic power for Group II decreased to the similar values of the ordinary school boys after stopping the running training. 3) Greatest value for aerobic power was obtained on Subject A as follows : 3.63 1/min (61.5 ml/kg. min) at 14.7 yr of age, 4.67 1/min (74.6 ml/kg. min) at 17.8 yr, 5.04 1/min (76.3 ml/kg. min) at 20.7 yr. 4) Improvement in running performance was closely related to the increase in aerobic power (1/min) for the junior runners during the age of 14 to 18 yr.
One third to one fourth of main life is devoted to growth and motor development. An urbanization and a lack of big muscular activity in childhood may lead to impaire development of individual physical activity and attendant function. A riding on a bicycle is the play which is so great favorite with the children. The purpose of this study was to determine the riding on the bicycle or cycling in children from view point of physiological aspect. In this experiment, at first, using a special electric device maximum and ordinary cycling speeds were measured. Forty children, aged 5 years of old of male and female, were employed as subject. The maximum and ordinary cycling speeds were 3.40m/sec-4.45m/sec and 1.30m/sec-1.65m/sec for male, 2.94m/sec-3.68m/sec and 1.20m/sec-1.52m/sec for female, respectively. There was a difference in the cycling speed among the size and type of bicycle, sexuality, and physical fitness level of subject. It is the further the purpose of this study to determine the oxygen intake and cardio response of the schoolboys and schoolgirls, aged 6-9 years old, during cycling with various speeds at different lanes. During cycling at flat lane heart rate and estimated oxygen intake were 113 beats/min-128 beats/min and 0.39 l/min-0.48l/min, respectively. It could be said that the physiological intensity of cycling is insufficient to improve the aerobic working capacity of children. Making comparison of the oxygen intake and heart rate between the flat lane and upward slope, those for upward slope were much more than for the flat lane.