Abstract
Severe exercise which taxes the human organism to its limits has been shown to produce very profound changes in the blood. In these preliminary experiments, venous blood from 3 runners was obtained. As soon as possible after the run, blood from arm veins was drawn without CO2 loss into syringes containing carefully neutralized potassium oxalate. The syringes were iced and immediately transported to the laboratory where the pH of the whole blood was determined at 38° C. with a glass electrode. The exercise consisted of running 440 and 880 yds. without competition. The runners were in different states of training, but the small number of determinations does not justify an attempt to correlate change in blood pH and muscular ability. The chief interest is that these pH values of blood after such severe exercise are probably some of the most acid ever obtained in normal subjects.
Great difficulties were encountered in drawing blood samples immediately after the exercise, due to almost total absence of skin blood and collapse of the superficial veins. In order to facilitate collection of blood, stasis was applied in several instances. But control experiments indicated that such a procedure must be avoided if correct results are to be obtained. However, stasis for 45 sec. during resting conditions, does not seem to induce any very marked effects.
It is also to be noted that there appears a rough correlation between the severity of the run as determined by the time performance and the degree to which the pH is depressed. The return to normal pH is in general comparatively slow, at least within the first 5 minutes after the exercise.
The following is example of 1 series of tests:
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