Can being in a relationship influence your grades?

The entire time that I have been at Baylor I have been in a relationship. Although it makes me very happy and the relationship is fulfilling, it requires a lot of time and effort. I am just wondering, does being in a relationship influence your performance in college? I might not be as happy if I were single, but I think I may have better grades. So much of my time each day goes toward maintaining my long-distance relationship. Because we are not in the same city, so much time is spent on the phone, as well as driving back and forth to visit one another. If all this time was freed up, I wonder if I was use it wisely, I wonder if it would improve my grades.