Darling, either you join him in sport or you go study. Being together in a relationship doesn't mean that you have to spend 24/7 or whatever time you have together. You do have your life, and he his. I am sure you squeeze some time and visit him during practise or something? You can even chat and ask how's his sports doing and all. When you love someone, you try your best to overcome any barrier. If you force him away from sports, I am pretty sure he's going to hate you for it.