[PART 1] Energy and Water Metabolism during Exercise
Twenty four basket ball, soccer and rugby champions who had been systematically trained for 6 years were selected for the study. Average age of subjects was twenty one years.
The minute volume, the oxygen consumption, the carbon dioxide production and the partial pressures of the alveolar gas as well as the loss of body fluid and sodium chloride due to sweating were determined during heavy exercise in the middle of summer. The extra caloric expenditure over the resting level was calculated from the oxygen consumption. Hematocrit ratios were measured before and after the exercise. Results may be briefly summarizd as follows:
(1) The minute volume, the oxygen consumption and the carbon dioxide production increased to approximately 6 times the resting level.
(2) The extra energy expenditure over the resting level was approximately 500 Calories per hour.
(3) The average loss of body fluid due to sweating was 25 cc/hr/kg. In contrast, the average amount of free water intake was 10cc/hr/kg which was equivalent to 40% of the loss of body fluid.
(4) When water intake during exercise was prohibited, the loss of body fluid approached to approximately 5% of the initial body weight.
(5) There was no change in the hematocrit ratios as determine4d before and after the exercise even in the face of severe dehydration.
(6) The average chloride concentration of the sweat from the hand was about 40 mEq/L. This is equivalent to a loss of NaCl as much as 60mg per hour per kg blody weight. The total loss of NaCl by sweating during the two hour exercise amounted to 7.89gm in athlete weighing 65kg.
[PART 2] Physiological Adaptation in Well-trained Athletes
Ten basket ball, soccer and rugby champions who had been systematically trained for six years were selected for the study, along with ten healthy medical students who served as the control group. the average age of subjects was from twenty to twenty one years. In addition, olympic champions of basket ball, soccer, bicycle and marathon(417 males and 79 females) were also selected for certain physical fitness tests. The minute volume, the oxygen consumption, the carbon dioxide production and the partial pressures of the alveolar gas were measured during the standard work output. At the same time, the pulse rate and the blood pressure, the subcutaneous fat thickness were also determined. The Harvard step-up test, the Schneider test and the standard treadmill test were employed as physical fitness tests. Results may be briefly summarized as follows:
(1) During exercise, increase in the minute volume and the carbon dioxide production was greater in non-athletes than athletes. Moreover, PAO^^2 was maintained at alower level while PACO^^2 was at a higher level in athletes during exercise than in non-athletes. On the basis of these findings, it is suggested that non-athletes tend to hyperventilate during exercise and also that the CO^^2 sensitivity of the respiratory center seems to be somewhat depressed in athletes.
(2) The pulse rate in athletes was not only slower during exercise but also returned to the resting level faster after the exercise than in non-athletes. The diastolic blood pressure was maintained at a significantly higher level I athletes.
(3) In general, various indices of physical fitness indicated that athletes were excellent than non-athletes.
(4) The total adiposity, the subcutaneous adiposity and the internal abiposity were significantly less in athletes than in non-athletes.