Pycnogenol helps prevent capillary leakage due to the antioxidant effects of several of its constituents. The extract also seems to recycle ascorbyl and tocopheryl radicals, helping to maintain vitamin C and E levels, which is thought to help protect inner vessel lining, reduce vascular tension, and strengthen capillary and vascular integrity. Taking Pycnogenol while training for exercise competitions and triathlon appears to improve performance compared to training alone. This effect has been attributed to the ability of the extract to reduce oxidative stress.