STUDIES IN THE PHYSIOLOGY OF MUSCULAR EXERCISE

Abstract

When one considers the great interest which has recently been evinced in the subject of acidosis, it is somewhat surprising to find that the most frequent cause of acidosis has received little attention.During and following vigorous muscular exercise, the acid-base equilibrium of the blood undergoes changes which are comparable in degree to those observed in severe diabetes or nephritis, and which may occur often in the daily life of any active, healthy individual.The investigation reported in this and the following papers is concerned with the direction, extent, and duration of these changes.Comparatively few studies of the acid-base equilibrium of the blood have been made during or after exercise.The reasons are not hard to find.Venous blood from the arm or other available surface veins may give little reliable information concerning conditions of the mixed venous blood and still less concerning the arterial blood supplying the tissues.The unreliability of venous blood and the difficulty and supposed danger of obtaining arterial blood from man have led most observers in the past to focus their attention upon the air from the deep parts of the lungs with the assumption that this air is in gaseous equilibrium with the circulating blood in the pulmonary capillaries.Although this mode of approach is indirect, much valuable and probably quite accurate