What Causes Severe Sinus Discomfort After Exercising?

I have severe sinus discomfort after exercise. I am an avid runner; running approx 6 miles a day 4-6 days a week. Recently Iâ??ve started doing sprint intervals, within minutes of finishing my work out on both occasions I have experienced pain in my gums/teeth, along with severe sinus pain. The pain in my gums and teeth subsides within about 15 min but my sinus only get worse; constant drainage, pain, watery eyes, lasting about 2 days much like a cold or bad allergies. I have do not have allergies or sinus problems otherwise.