VENOUS TONE SKIN- AND MUSCLE BLOOD FLOW IN FOREARM AND HAND DURING EXERCISE

Alterations of venous tone in superficial forearm veins, of peripheral venous pressure, skin- and muscle blood flow in the contralateral forearm, of heart rate and respiration were studied in healthy subjects during leg exercise in the supine position on a bicycle ergometer. After beginning of exercise there occured regularly increases in venous tone which were, however, reduced to resting values in the course of light work load (60 Watt). During moderate to severe work load (90, 160 Watt and vita-maxima work-load) venous tone remained increased until the end of exercise. In the recovery period values often fell below the resting values. Peripheral venous pressure showed augmentations proportional to work load which were diminished to pre-exercise level in some cases during severe exercise and in the remaining studies shortly after the end of exercise. At the beginning of exercise skin blood flow decreased and showed mirrorimage reactions to alterations in venous tone. With longer duration and with heavy work load, secondary increases of skin blood flow were observed. After cessation of exercise, pre-exercise values were exceeded. Muscle blood flow first increased and in the course of moderate to severe work load decreased. In all studies a marked decrease of muscle blood flow was observed after the completion of exercise. Circulatory and thermoregulatory adjustments as well as emotional factors influence the reactions. The neurally effected venomotor reactions are significant especially for the adaption of vessel capacity to the conditions existing under muscular work. © 1969 Springer-Verlag.