This study was to examine the effects of quantity of taking salt diet on the body during exercise. The subjects were made to do endurance exercise on each after intake of the moderate-salt diet, the much-salt diet and a little-salt diet in a fixed duration. The results were obtained as follows: 1) Under the much-salt diet intake, responce of systolic blood pressure and heart rate showed small increment during the exercise. 2) Under a little-salt diet intake, the CK-MB/CK ratio showed large increment during exercise. 3) Under the much-salt diet intake, serum BUN values were decreased compared with under the other diets. Under a little-salt diet intake, serum BUN, Uric Acid and Triglycerides values were increased, on the contrary serum Glucose values were decreased in resting condition. Especially, under a little-salt diet intake, serum BUN values were increased during the exercise. 4) The value of urinary sodium excretion was varied in response to the intake of salt. The value of urinary potassium excretion showed no change under the much-salt diet intake. But it showed decrease under a little-salt diet intake. 5) Under a little-salt diet intake, the creatinine clearance values were decreaced during and after the exercise. The above mentioned findings suggested that the change of salt intake itself may become a stressor to the body and it is necessary to pay much attention when we exercise under these condition.
A simple exercise test with vertical jumping was developed for children. The vertical acceleration wave form of back was measured with strain gauge type transducer. After amplification and rectification, the signal of positive acceleration was converted to frequency with voltage-to-frequency converter (VFC) and VFC signals were decoded by a digital counter. The digital output was normalized by gravitational value and defined as physical activity rate. 10 young males and 24 schoolchildren jumped at several frequencies and oxygen uptake, physical activity rate and heart rate were measured. Also 28 children under school age jumped arbitrary and heart rate and physical activity rate were recorded. The results showed that the oxygen uptake per body weight had good correlation to the physical activity rate (r=0.95) . Although heart rate was significantly different with ages, physical activity rate which was defined as an index of exrecise test, was no significant difference with ages and weights (α<0.05) . The results indicated that this jumping test was helpful to make exercise stress test for younger children.
In 31 asthmatic children, we investigated the change of the structure on the time of living, an amount of exercise by pedmeter and measured pulmonary ventilatory function during 28 weeks swimming training. The result showed 58.07% of contribution factor to the structure on the time of living on children with asthma and dynamic play time after school were significantly shorter in asthmatic than non-asthmatic children (p<0.05) . After 28 weeks, we could not find any significantly differences of dynamic play time between asthmatic and nonasthmatic children. An amount of exercise in daily life from the point of view of walking step number by pedmeter were significantly less in aged 6-9 years boys and girls, and aged 10-12 years boys than non-asthmatic children (respectively, p<0.05, p<0.01) . However, after 28 weeks, we could not find any differences between asthmatic and non-asthmatic children. Forced vital capacity (FVC) and rate of forced expiratory volume on one second (% FEV1.0) were increased after 28 weeks than the begining of swimming, and we found the strength of their breathing muscles. On according to perform the great swimming distances (averages 220m in boys, 325m in girls), all asthmatic children became very lively and actively.
The purpose of this study is to evaluate the effects of muscle pump of pedaling exercise on blood circulation. Lower body pressurization device was used to provide negative pressure and positive pressure on the lower body of subjects in recumbent position. This device is also equipped with bicycle ergometer in it. Five healthy male college students volunteered for subjects. Whole experiment for each subject was divided into pre-control stage (0 mmHg), LBPP (lower body positive pressure) stage (+40mmHg), LBNP (lower body negative pressure) stage (-40 mmHg) and post-control stage (0 mrHg) . 50 (watt) exercise and 100 (watt) exercise preceded by resting period were loaded during each stage and following parameters were determined: ECG, phonocardiogram, carotic pulse wave, VO2, cardiac output, and blood pressure. Pre-ejection period index (PEPi), Left ventricular ejection time index (LVETi), PEP/LVET and stroke volume (SV) were calculated from the recorded data. Results suggested following conclusions: 1) In rest condition, LBNP caused marked increase in HR, PEPi, and PEP/LVET and remarkable decrease in Q, SV, and LVETi. These findings indicate that LBNP affects venous return and exaggerates venous pooling in lower body. 2) It was shown that muscle pump of pedaling exercise counteracts the effects of LBNP and the findings mentioned above were largely abolished by pedaling exercise of 100 (watt) . 3) LBPP caused no apparent change in the studied parameters except blood pressure. Blood pressure increased by LBPP probably because of rising in total peripheral resistance.
Subjects were long distance runners (n=6), middle distance runners (n=6), and sprinters (n=4) . They exercised in incremental exercise and steady state exercise. The anaerobic thershold (AT), O2deficit at AT (AT-O2df), and time constant of Vo2 (τ) which were obtained from these exercise tests were compared among three groups of runners, and the interrelationship of three parameters was elucidated. The results were as follows. 1) AT-Vo2of long distance runners was the highest followed by the values of middle distance runners and sprinters, successively. The AT-Vo2per weight and per Vo2max also decreased in the same order. 2) AT-O2df per weight of long distance runners was as high as that of middle distance runners, and was significantly higher than that of sprinters. 3) τ of long distance runners was shorter than that of middle distance runners, but was not significantly shorter than that of sprinters. τ of long distance runners was shorter than the reported one of untrained people. 4) ΔAT-Vo2 (difference between AT-Vo2and Vo2at rest) related to neither AT-O2df nor τ. However, the ratio of AT-O2df/τ significantly related to the ΔAT-Vo2 (r=0.795, n=16, p<0.001) . From these results, the highest values of AT-Vo2obtained in long distance runners would be due to both high AT-O2df and short τ.
The series of ECG examination were performed to study the influence of different kinds of exercise on heart of two untrained middle aged healthy male volunteers. One of them was assigned to run 10 kilometers or so, as fast as he could, once a day for 17 days. The other was assigned to run on a treadmill of three degree gradient for 20 minutes with a speed of 150 meters per minute once a day for 10 years. This volume of exercise was designed at a workload requiring 2/3 of his VO2max value. In the former case, frequent supraventricular premature beats with ventricular aberrant conduction occurred on the 21 st day from the beginning of the study. These changes on ECG were complicated with sinus arrhythmia and complete AV block on the 23 rd day. Sinus bradycardia and supraventricular bigeminy with ventricular aberrant conduction were noted on the 44 th day. Supraventricular bigeminies still persisted on the 213 th day, however they disappeared after that. The latter developed interpolated ventricular premature beats at rest for the first time in the 5 th year from the beginning of the study. These premature beats disappeared during exercise and recurred at rest. In the 8 th year ventricular premature beats became to show bigeminies. These results suggest that the severe exercise could cause various types of arrhythmia for a long period of time after the cessation of exercise even if the term of exercise would be short. On the other hand, the moderate load of exercise could not cause clinically significant arrhythmias inspite of continuous performance for a long term.