What Career Should I Pick?

In my opinion they are both hard fields to get into, but I think you have a talent as an author. Also writing is a more stable career so maybe you should major in English in college and pursue sports on the side. That way somehow if your plans to become an athlete fall through, you always have your degree. There is so much you can do with an English/writing degree you can become an author, write for magazines or newspapers, work for a book publishing company or even teach. Good luck!