In order to investigate an effect of the excess fat of obese men on the respiratory-cardiovascular system, VO₂max was measured for seven obese, 16 ordinary and seven lean men. All subjects were university students, ages 18 to 25 years. Body composition was determined by densitometry. Furthermore, six non-obese young men participated in an added-weight experiment so as to estimate an effect of the excess fat of obesity. Results showed that there were no statistically significant differences in the absolute values of VO₂max, VEmax, and HRmax among the groups. Concerning the relative value of VO₂max to body weight, the obese group showed a significantly lower value of 40.4 ml/kg-min than the lean and ordinary group values of 51.5 and 48.8 ml/kg-min, respectively. However, no significant difference was found between the relative values of VO₂max per lean body mass of any of the groups. VO₂max for the obese group was 54.0 ml/kg-min, 56.0 for the lean group and 57.7 for the ordinary group. Such trends were very similar to the results of the added-weight experiment. Based on the values for the subjects in this study, this leads to the conclusion that the excess fat of obese men might act only as an inactive load and might not affect the ability of the respiratory-cardiovascular system. Besides, the threshold of obesity for men proposed by Behnke and Wilmore might be reasonable from the viewpoint of the absolute and the relative values of VO₂max.

Competitive gymnasts are confronted with the problem of weight loss before a competition. They intend to decrease body fat, but not muscle. One of the most reasonable method for the purpose is a dieting. Neverthless, a dieting often leads to decrease not only body fat but also lean body weight (LBW) of which 47% is composed of muscle. That is, a dieting has the possibility of decreasing the competitive performance. The well-regulated diet is, therefore, required very much for weight loss of the gymnasts. The body composition (under-water weighing), physical working capacity (submaximal endurance capacity, muscle strength and vertical jump) and blood constituents of seven female gymnasts were measured before and after the 33 day-diet. They, ranging from 18 to 22 years of age, were high ranked athletes in Japan. The diet program was arranged by the dietitian taking gymnasts' favours into consideration. The averaged daily diet evaluated by means of a dietary recall had 1194 kcal with 54.7g of protein, 28.5g of fat and 179.9g of carbohydrate. On the other hand, the usual intakes just before the dieting were 1722 kcal in energy, 43.0g in protein, 57.1g in fat and 269.2g in carbohydrate. All the intakes of vitamins and minerals of the diet were higher than the Japanese recommended dietary allowance (RDA) . They practiced about four hours a day, six days a week, during the diet period. The daily energy expenditures before and at the last stage of the dieting were 2332 kcal and 2551 kcal on the average respectively, which were estimated through motion and time study. After the dieting body weight decreased significantly from 52.11kg to 48.35kg, of which difference was composed of 2.99kg of body fat and 0.77kg of LBW. The decrease of body fat was statistically significant, but LBW was not so. Concerning all the physical working capacities in oxygen uptake and heart rate, muscle strength except trunk extension strength, and vertical jump, there were no significant changes after the dieting. But respiratory exchange ratio (R) decreased significantly at the same work loads. This decrease suggested increased usage of stored body fat as energy during daily practice, and might support the significant decrease of body fat. Most of blood constituents were still in normal ranges in spite of significant changes. Marked change was found in serum FFA which increased three times after the dieting. This change also meant the increased usage of body fat after the dieting. These data indicated that the diet program arranged in this study proved successful and the wellregulated diet was very effective in conditioning the body composition and the physical working capacity of female gymnasts.

The effects of wind and rain on exercising humans have not been fully investigated in the field of sports science. The purpose of this study was to investigate the characteristics of thermoregulation and cardiovascular-respiratory responses during exercise in a climate chamber that allowed control of wind and rain. Seven healthy males performed treadmill running at 70%VO_2max for 30 min under three conditions (CON, control ; WIND, wind only; WIND&RAIN, both wind and rain). The temperature was 27.0℃ under the three conditions. Relative humidity was 60%RH except under the WIND&RAIN condition (100%RH under WIND&RAIN condition). The wind velocity corresponded to running velocity in the open air and the precipitation was 90 L/h. Under the WIND&RAIN condition, both body trunk and extremities skin temperature (T_sk) showed a clear decrease for the first 5 minutes after the start of running, and was significantly lower during the running period than under the other two conditions (p<0.05). Rectal temperature (T_re) did not differ significantly among the three conditions. An interaction was observed between conditions and time in terms of minute ventilation (VE) (p<0.05). Under WIND and WIND&RAIN conditions, VE was higher than under CON condition while running. Oxygen consumption, heart rate and respiratory exchange ratio did not differ significantly among the three conditions. These results indicate that wind and rain in a natural environmental condition with neutral temperature (27.0℃), cause a decline in T_sk, and may become factors that influence performance, similarly to temperature and humidity.

The present study examined the effects of having bigger amount of protein than usual in competitive season on lean body weight (LBW), cross-sectional area of thigh and abdomen, muscle strengths, blood constituents and urinary urea nitrogen. Seventeen male varsity throwers (javelin, discus, hammer and shot put) ranging from 19 to 22 years of age, were divided into two groups ; Group A (N=9) with a more protein diet (2.1 g·kg^-1·d^-1), and Group B (N=8) with a usual amount diet (1.5 g·kg^-1·d^-1) . The experimental period was 62 days. During this period, they practiced six days a week. Three days were for throwing practice. Other three days were for weight training. All subjects lived in the same dormitory, and their life styles were similar to each other. The averaged daily diet of Group A evaluated by means of a weighing method had 3824 kcal with 175 g of protein (2.0 g·kg^-1·d^-1), 115 g of fat and 552 g of carbohydrate. The averaged daily diet of Group B had 3441 kcal with 130 g of protein (1.5 g·kg^-1·d^-1), 76 g of fat and 559 g of carbohydrate. All the intakes of vitamins (A, B₁, B₂, C) and minerals (calcium and iron) of the diet of each group were higher than the Japanese recommended dietary allowance. After the period, body weight, %fat, fat and LBW of both groups did not change significantly. Muscle strengths and cross-sectional areas in abdomen and thigh of both groups did not change significantly. Urinary urea nitrogen of both groups did not change significantly. Blood constituents (RBC, Hb, Ht, TP, Alb, BUN) of each group were still in normal ranges in spite of significant changes. No significant changes in body composition and muscle strengths were found in each group. These results, therefore, indicated that the more protein diet (2.0 g·kg^-1·d^-1) was not effective for increasing LBW and muscle strength of varsity throwers in competitive season.

Energy expenditure during sport activities has been determined traditionally by the Douglas Bag Method and the Motion Time Study. However, those two methods do not yield accurate values when used in long continuous and/or vigorous physical activities. This study, therefore, measured oxygen uptake by means of a portable device “Oxylog”, and determined the energy expenditure of many sport activities. The experiments were carried out with 13 untrained male subjects (UTS), and 30 trained male subjects (TS) . The 30 trained men consited of ten tennis players, ten badminton players and ten basketball players. UTS played one set of doubles (tennis), one set of singles (badminton), two sets of singles (table tennis), two games (bowling) and jogged 10 minutes, But TS played only their major sports : one set of doubles (tennis), one set of singles (badminton) and two 20-minute halves (basketball) . The results were 0.172±0.017kcal⋅kg^-1⋅min^-1 for jogging (UTS), 0.146±0.028kcal⋅kg^-1⋅min^-1 for badminton (TS), 0.133±0.021kcal⋅kg^-1⋅min^-1 for basketball (TS), 0.130±0.018kcal⋅kg^-1⋅min^-1 for badminton (UTS), 0.102±0.016kcal⋅kg^-1⋅min^-1 for tennis (TS), 0.096±0.014kcal⋅kg^-1⋅min^-1 for tennis (UTS), 0.089±0.019kcal⋅kg^-1⋅min^-1 for table tennis (UTS), and 0.055±0.009kcal⋅kg^-1⋅min^-1 for bowling (UTS) . In comparison with UTS, TS exhibited higher values in tennis and badminton. This is considered to result from TS's better training. This result indicates that energy expenditure in playing sports activities depends on the level of player's ability. The method employed in of this study is believed to be the best choice at present. Many other sport activities must be reexamined in detail using this method.

The most characteristic feature of the triathlon is integration of the three endurance activities including of swimming, cycling and running, into a continuous task. So, it is necessary to identify the cardiorespiratory responses during the triathlon to develop a beneficial training program. Twelve male triathletes conducted a simulated triathlon test in a laboratory. This test consisted of continuous swimming, cycling and running using a flumepool, a bicycle ergometer and a treadmill, respectively. The exercise intensity and duration were 60% of maximal oxygen uptake during swimming, cycling and running for 30, 75 and 45 min, respectively. The results demonstrated that the residual effects of the prior exercise stage were observed during the latter exercise stage : The prior swimming stage produced an increment of oxygen uptake and heart rate during the cycling stage ; Prior swimming and cycling stages increased oxygen uptake, minute ventilation, heart rate and ventilatory equivalent to those during the running stage. These results suggest that the residual effects of the preceding exercise decreased the mechanical and respiratory efficiency by increasing the physiological demands of conducting the subsequent exercise. Therefore, triathletes are recommended to train themselves in a continuous task rather than separately.

This study examined the physiological response to different water depths in recreational synchronized swimming. Nine middle-aged, female, recreational swimmers carried out the same team free routines in deep water (deep-water synchronized swimming: DWS) and shallow water (shallow-water synchronized swimming: SWS). Heart rate (HR) was measured continuously during each performance, combined with estimation of metabolic equivalent (MET) values using individual linear regression equations of HR-oxygen uptake. These equations were created using the results of 12 water activities. Blood lactate concentration and systolic blood pressure were measured at the 1/3 and 2/3 stages and immediately after each performance period. HR and estimated METs during DWS (mean±SD, 152.9±7.5 beats·min^-1 and 7.3±1.2) were significantly higher than those measured during SWS (131.8±11.3 beats·min^-1 and 5.7±0.8). Blood lactate concentration and systolic blood pressure measured immediately after DWS were significantly higher than those measured after SWS. With DWS, blood lactate concentration at the 2/3 stage and immediately after the performance were significantly higher than those measured at the 1/3 stage, whereas in SWS no significant difference was found in these values at any time period. In conclusion, the exercise intensity of DWS was high and SWS moderate. The predominant sources of energy may be phosphocreatine stores and aerobic metabolism during these performances. It is possible that glycolysis may also play an important role in energy requirements during the 2/3 stage and immediately after a DWS performance.

Total muscle mass is thought of as one of the intrinsic limiting factors of aerobic power. But it is not yet clarified how the total muscle mass limits the magnitude of aerobic power. The purpose of this study was to clarify the relationship between total muscle mass and aerobic power and to make a further discussion conscerning its limiting factors. 17 sedentary students with a mean age of 19.3 (18-23) years, and 17 varsity footballers 19.9 (19-21) years old, were measured for lean body mass, which was an approximate indicator of the total muscle mass, by underwater-weighing method and VO₂ max by bicycle ergometer. The correlationship between lean body mass and VO₂max for sedentary students was found to be higher (r=0.821) than for footballers (r=0.595) . It was also shown that footballers had a significantly larger VO₂max per 1kg of lean body mass than sedentary students. Previous studies showed that the increment of VO₂max through endurance training was caused by the increment of such factors as mitochondria, maximum cardiac output and maximum stroke volume, and was not by lean body mass. So, it was concluded that lean body mass was a reasonable limiting factor for sedentary students, but was not a stable factor of VO₂max because of lower linearlity for footballers and the significant difference on VO₂max per 1kg of lean body mass between two groups.

This study was designed to find out about the body composition of ordinary Japanese adults, and to clarify how gender and age have effects on it. The subjects were volunteers living in the northern, central and western parts of Japan. They consisted of 154 males and 142 females aged 20 to 59 years. Their body height and weight did not differ by more than 1 S. D. from the mean of the given age category cited in the Japanese Ministry of Education Annual Report. Body composition was estimated from densitometry using an underwater weighing method and pulmonary residual volume measurement. Within each age group, there were significant differences in body height, weight, body density, percentage body fat, lean body weight, fat per 1 m of body height and lean body weight per 1 m of body height, but there was no significant difference in fat between males and females. Percentage body fat and fat increased significantly with age in both genders. The rate of increases of fat were calculated to be 14.2% for males and 10.7% for females per decade. Lean body weight decreased significantly with age in males, decreasing at a rate of 3.3%. However, the lean body weight of females stayed constant over the given ages of this study. These results show that the difference in body weight between males and females is caused by lean body mass, not by fat.

This study was designed to analyze physiologically recreational synchronized swimming and speed swimming. Two types of recreational synchronized swimming (Long face-in time performance : LFIP and Short face-in time performance : SFIP) and maximum exertion in the 200-m free style swimming (200 mFR) were measured in six recreational middle-aged female swimmers. LFIP and SFIP were conducted in shallow water. The percentage of face-in time for LFIP was about 10% longer than that of SFIP. Heart rate (HR) during each exercise was measured continuously. Blood lactate concentration (La), the rate of perceived exertion (RPE) and systolic and diastolic blood pressure (SBP, DBP) were measured after each exercise. Average HR during the LFIP, SFIP and 200 mFR were 133±12, 132±13 and 153±12 beats·min^-1 (mean ± SD), respectively. La was 2.4±0.7 mmol·1^-1for LFIP, 2.2±0.6 mmol·1^-1for SFIP and 5.7 ± 2.4 mmol·1^-1for 200 mFR, respectively. SBP was 181±32 mmHg for LFIP, 166±22 mmHg for SFIP and 185±30 mmHg for 200 mFR, respectively. No significant differences were observed in blood pressure among the three exercises. SBP of 200 mmHg or higher after LFIP and 200 mFR was observed in some subjects. HR, La and RPE for LFIP and SFIP showed no significant differences, but were significantly lower than those of 200 mFR. These results show that the exercise intensity of LFIP was moderate and was similar to that of SFIP. LFIP, however, caused a marked rise in SBP. Thus, SFIP may be more recommended for health promotion to recreational middle-aged swimmers than LFIP.