Limb circulation during arm and leg exercise in supine position.

Abstract

In 3 healthy young males, axillary and femoral arteriovenous (A-V) O2 and lactate differences were measured through percutaneous catheters during arm, leg, and combined arm plus leg exercise. During exercise the average A-V O2 difference increased up to 50% in the resting limbs and a positive A-V lactate difference was present, indicating an uptake of 5-12% of the lactate produced in the working muscles at that time. The fractional clearance of lactate in resting limbs increased during exercise up to 0.3 in the arms and 0.4 in the legs. Only a minor part of the decrease of pH in venous blood from exercising limbs was related to lactate production, the major part was due to volatile acids eliminated in the lungs. During combined arm plus leg exercise the A-V O2 difference over the working limbs was significantly higher in relation to work load than when only the arms or only the legs performed exercise, indicating a lower limb blood flow. Despite this lower blood flow the arterial lactate concentrations were appropriate for the work loads, indicating a more efficient circulation.