Intramuscular oxygen partial pressure in the healthy during exercise

The oxygen partial pressure (pO(2)) in the anterior tibial muscle was measu red in n = 12 (6 physically active and 6 sedentary) apparently healthy subj ects. This was the first time a flexible micro catheter with an outer diame ter of 0.45 mm was used during skeletal muscular activity in men. A two lev el tread mill test which is used in the diagnosis of peripheral arterial oc clusive disease was chosen to induce physical stress. In the healthy volunteers a pO(2) increase was noted at the beginning of ex ercise. This was followed by a pO(2) decrease because of an increased O-2 d emand in the working muscle. The initial pO(2) increase was thought to be d ue to the recruitment of capillaries and not the subsequently increased hea rt rate. At rest and during activity pO(2) values were higher in physically active subjects than in the sedentary and the exercise induced decrease of pO(2) values was slower and in addition to this the compensation to baseli ne values quicker.