Background: Physical inactivity increases the risk of cancer and atherosclerosis;the impaired regulation of angiogenesis is often associated with the development of these diseases. Wehypothesize that exercise increases circulating sFlt-1, an endogenous VEGF inhibitor, which may functionallydecrease plasma levels of free VEGF. Material/Methods: 5 healthy male adults were assigned to a treadmillexercise study. The peak speed and the time spent at peak speed on the treadmill were 4.8+/-1.0 miles/hand 6.8+/-2.6 minutes, respectively. Plasma levels of sFlt-1 and VEGF were determined using ELISA (R&DSystems). Results: Basal plasma levels of sFlt-1 (before exercise) were 48.8+/-9.0 pg/ml. Plasma levelsof sFlt-1 increased to 72.9+/-14.6 pg/ml at 0.5 h after exercise, compared to the basal levels (49% higher,P=0.0048). The plasma levels then returned to 47.5+/-14.3 and 43.3+/-10.2 pg/ml, at 2 and 6 h after exercise,respectively. There was a significant positive correlation between% increase in plasma levels of sFlt-1and total peak oxygen consumption during exercise (R[sup]2[/sup].=0.8244; P

Keywords: Atherosclerosis - prevention & control, Exercise - physiology, Exercise Test, Fibroblast Growth Factor 2 - blood, Neoplasms - prevention & control, Risk Factors, Solubility, Vascular Endothelial Growth Factor A - blood, Vascular Endothelial Growth Factor Receptor-1 - blood