Closing volume (CV) along with vital capacity (VC), expiratory reserve volume (ERV), and residual volume (RV) were determined on seven swimmers and seven physical education students in three positions (standing, supine, and prone) both in air and during head out water immersion. Lung volumes were also measured during bicycling and swimming to clarify if airway closure, as measured by CV, occurred during tidal ventilation in exercise.
CV/VC and CC/TLC in standing position in air were significantly lower in our subjects than standard values obtained by Buist, A.S, and Leblance, P. This may suggest that the lung elastic recoil was increased by physical training.
There was no difference among CV's measured in three positions, but CV increased when subject was immersed in water.
Tidal volume (TV) in rest sitting position in air was in middle level of VC, and expanded evenly toward both expiratory and inspiratory sides with the increase of work load in bicycling. The level of tidal ventilation in rest supine position in air was lower than that in sitting position, and the increase in TV took place at the expense of IRV rather than ERV. FRC fell at rest in water, and the mean respiratory level shifted toward inspiratory side to increase ERV and FRC and to decrease IRV as the smimming speed increased.
FRC and CC got close in supine bicycling, suggesting the increased probability of airway closure within the range of tidal ventilation level. CC was much less than FRC in other types of exercise.

Maximum expiratory and inspiratory flow-volume curves (MEFV, MIFV) along with vital capacity (VC), expiratory reserve volume (ERV), and residual volume (RV) were determined on 7 swimmers and 7 physical education students (control group) in three positions (standing, supine and prone) both in air and during head out water immertion, in order to analyze the effects of body positions, immersion and swimming training on their lung mechanics.
Total lung capacity in standing position decreased in water as a result of decrease in both VC and RV. The ERV in standing position significantly fell in water, while IRV increased. Lung volumes both in supine and prone position did not change significantly in water except an increase in ERV in supine position. The fact that lung volumes decreased more in the standing position in water than horizontal positions probably means that the thorax and abdomen in standing position is more sensitively influenced by the hydrostatic pressure compared with horizontal positions. Lung volumes of the swimmer tended to be larger than that of the control group, while the influence of immersion on lung volumes was similar for the both groups.
Peak flow rate (Vp) was smaller during inspiration than during expiration. Vp decreased more eminently during inspiration in water, while it tended to decrease in water during both expiration and inspiration. When body position turned from standing to supine or prone, Vp tended to decrease, and influence of postural change on Vp was more marked during inspiration than during expiration. By contrast, V₅₀, V₂₅ and VV were notably larger during inspiration than during expiration. These indexes tended to decrease in water during both expiration and inspiration.
The difference in dynamic lung mechanics between the swimmer and the control group appeared more apparently during inspiration than during expiration, and the swimmer showed significantly higher Vp, V₅₀, V₂₅, and VV in inspiration than the control group probably due to the effect of their swimming training.

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.

The purpose of this study was to investigate the possible individual difference in temperature regulating ability during identical relative exercise load under various temperature environments.
Seven healthy males, aged 21 to 26 years, performed bicycle ergometer exercise of 60% VO₂max for 60 minutes. All exercises were carried out in a climatic chamber under the conditions of 15°C (RH=70%), 25°C (RH=55%) or 35°C (RH=45%) . Herat rate, O₂ consumption, pulmonary ventilation, rectal temperature, mean skin temperature, local sweat rate at the lower part of scapula and total sweat rate were determined intermittently through the experiments. Moreover, heat loss by evaporation, radiation, convection and effective sweat rate was calculated using the heat valance equations.
The results obtained are as follows :
1. The increase in rectal temperature at the end of exercise was almost identical in 15°C and 25°C but significantly higher in 35°C.
2. A significant positive correlation was observed between mean skin temperature (ΔTsk) at the end of exercise and effective sweat rate (r=0.468, p<0.05) during exercise.
3. Inspite of the equality of relative exercise intensity (60%VO₂max), marked individual variations were observed in rectal temperature during exercise.
4. The subjects who showed marked increase in rectal temperature during exercise showed less marked increase in mean skin temperature in 15°C and 25°C and less marked increase in local sweat rate in 35°C than other subjects.
It would be concluded that the main cause of individual variation in rectal temperature during exercise depends on difference in evaporative heat loss in hot environment and difference in skin temperature in mild or cold environment.

The present investigation was designed to examine the effects of warming-up (W-up) on the blood lactate kinetics during 5 minutes of pedaling exercise. Five healthy male adults were the subjects. The intencity of the criterion task (CT) was about 80% VO₂max, and that of the W-up was a work load corresponding to the anaerobic threshold. Between W-up and CT there were five-minute rest periods on the bicycle ergometer. In order to determine the blood lactate values, blood samples were taken from the antecubital vein at the following times: rest, pre-CT, and 3, 5, 7, and 30-minutes after CT. Expired gas was analysed continuously for the calculation of VO₂, VCO₂, R, VE. The heart rate was recorded every min-ute from ECG.
Blood lactate values increased 3.23±0.91 mmol/l after W-up, a significant increase over the resting values. The peak blood lactate during the W-up experiment (4.62±0.84 mmol/l) was significantly lower than that of the control experiment (6.48±1.69 mmol/l) . Differences in lactate before and after CT (ΔLa) was found to be significantly lower in experiments with W-up (1.39±0.99 mmol/l) as compared with control experiments (5.37±1.62 mmol/l) . In one subject, the blood lactate levels decreased during CT after W-up, while lactate levels increased during CT without W-up. VO₂ during CT were very similar in both experiments. These results indicate that this kind of W-up delays the rate of blood lactate accumulation during CT.

A study was conducted to elucidate the changes in circulatory responses to sudden strenuous exercise (SSE) using beat-by-beat analysis of heart rate (HR), stroke volume (SV) and blood pressure (BP) . The effects of warming-up on these responses were also studied.
Six healthy male students volunteered for the study. A bicycle ergometer was prepared for SSE. The intensity and duration of SSE were 100% VO₂max and 1 min, respectively. Warming-up of 80% VO₂max for 5 min followed by SSE. The interval between SSE and warming-up varied from 5 to 30 min. A control experiment was also performed without warming-up.
The main results obtained were as follows :
1) BP decreased in the initial stage of SSE, followed by a steep increase. This temporary drop in BP was prevented by warming-up. This might contribute to the prevention of myocardial ischemia which is occasionally observed in the initial stage of SSE without warming-up.
2) Time constants of HR and SV during SSE were shortened by warming-up with long intervals, while the time constant of BP was shortened when the interval was short.
3) The recovery response of each parameter was accelerated by warming-up, but the effect of warming-up had almost disappeared after a 30 min interval.
These results suggest the following conclusions :
Warming-up accelerates the up-stroke and recovery of circulatory responses to SSE, but these effects of warming-up are strongly influenced by interval time. In particular, the effect of recovery acceleration is almost abolished by a 30 min interval.

Theoretical principle of the indirect method for cardiac output determination by continuous gas-analysis of prolonged expiration was introduced and its practical utility and error sources were discussed.
Merits and demerits of this method are as followd;
1) No blood sampling nor catheterzation is required.
2) Nonphysiological gas inhalation or injection of dye or other substances are not required.
3) Real time determination of cardiac output is possible when used with online computor processing.
4) Repeated measurement on the same subject is able to perform once every two minute at rest and once a minute during exercise.
5) Measurement during exercise is performed without any dificulty.
6) Several suppositions which used in this method may cause some error, especially anemia and unevenness of ventilation-perfusion ratio are possible two major error sources.
Using a gas-spectometer, cardiac output of six subjects was measured by this principle at rest and during exercise of several intensities on a bicycle ergometer. Average values of cardiac output were 4.5, 7.5, 9.4, 12.3, and 14.1 1/min. at rest and during exercise of 150, 300, 450, and 600 kpm/min., respectively.
From the results, utility of this method was practically confirmed for application to exercise physiology.

Effects of long term physical training on body composition and physical fitness were studied on 110 healthy males aged between 28 and 34 years. Two and a half hours training of soccer, swimming, running, judo and other kinds of exercises were assighned to the subjects daily except sunday for 8 months. Body weight, overweight, body fat, skinfold thickness, blood pressure, vital capacity, body flexibility, power, grip strength, maximal work capacity, and 6 kinds of sport tests were compared before and after the training.
1) Energy cost of the daily exercise was estimated at about 950 Cal., and intensity of the exercise was deduced to be 4 in RMR (corresponds to about 5 in Nets) on the average.
2) Body weight did not change significantly on the average. However, obese subjects lost their weight, lean subjects gained, and normal weighted subjects did not change their weight significantly.
3) Body fat calculated from skinfold thickness decreased markedly, and the more fat the subjects had initially, the more fat they lost.
4) LBM increased in almost all cases. Obese subjects lost more fat than LBM they gained, and lean subjects gained more LBM than fat they lost. Normally figured subjects gained the same weight of LBM as the fat they lost.
5) Physical figure tended to converge by the training into some range in which the relationship between body weight and height is 4-5% more stout than that of average Japanese male adults.
6) Overweight calculated from weight and height may be used as a valid indicator of obesity for untrained people but not for well trained. While body fat can be a good indicator of that for the both groups.
7) Body fat of the subjects who had high work capacity was mostly under 13%, and that of the subjects whose work capacity was poor was mostly over 13%, while, that of the subjects whose work capacity was medium scattered in the both sides of 13%.
8) Performance of both aerobic and anaerobic exercise improved markedly by the training.

The purpose of this investigation is to evaluate the effects of muscle pump by pedaling exercise on blood circulation and define its properties. Lower body pressurization device equipped with bicycle ergometer was used to provide negative pressure on the lower body of subjects in recumbent position. Seven healthy male collage students volunteered for subjects.
Whole experiment for each subjects was divided into control stage (0 mmHg), -20, -40, and -60 mmHg LBNP (lower body negative pressure) stage. Preceeded by resting period, 25, 75, and 125 W exercise in experiment 1, 50 and 100 W exercise in experiment 2 were loaded using bicycle ergometer with revolution of 60 rpm during each stage. Following parameters were determined: HR, SV, Q, and blood pressure.
The results obtained were as follows;
(1) In resting condition, LBNP caused significant decrease in SV and Q in spite of marked compensatory increase in HR.
(2) These effects of LBNP were cancelled in -20 mmHg or mostly cancelled in -40 and -60 mmHg by pedaling exercise of 50 W or more.
(3) Effect of muscle pump by pedaling exercise is apparent in light exercise such as 25 or 50 W arriving to a plateau with more intensive load.
(4) Muscle pump action by the same exercise condition is more effective under more severe LBNP.
(5) Light exercise in LBNP caused decrease in HR, probably because of pressure reflex initiated by restoration of blood pressure.
These results leed us to a conclusion that light pedaling exercise produces a powerful pumping action nearly enough to compensate the circulatory disturbance by strong LBNP.

A study was performed to investigate the validity of the derivative of the ear densitogram for measurement of left ventricular ejection time (LVET) .
Nine male college students performed bicycle exercise at an initial work load of 0 watt (W), subsequently increasing by 60W every 3 min up to 240W. The LVET derived from the derivative of the ear densitogram (LVETe) was compared with that derived from the carotid pulse wave (LVETc) obtained at the same time.
The results were as follows:
1. There was a high correlation coefficient, r=0.987 (P<0.01), between LVETe and LVETc.
2. At rest, LVETe showed a tendency to coincide with LVETc. In contrast, LVETe became longer than LVETc during exercise, and the higher HR became, the larger the difference between the two.
3. In the individual regression equations between LVETe and LVETc, the slopes and the intercepts were nearly identical.
4. The following equation was proposed for the correction of LVETe during exercise. LVET=-0.147⋅HR+ LVETe+ 8.3
From these findings, it was concluded that the validity of the derivative of the ear densitogram for estimation of LVET is sufficiently high. LVETe at rest is valid for the estimation of LVET without correction. During exercise, however, LVETe shows a tendency to be longer than LVETc, and thus it is desirable to correct LVETe using the above equation.