Change that "or" to "and" If you are serious about a SA, the best thing you can do is learn to love to run. Join track now (indoor winter is just starting) and run through the spring track, do whatever summer practices your school offers and then come back out in the fall for XC. Setting a consistent, solid running base, will help set you up for success. Running is all about building up mileage to build endurance and prevent injuries. Plus, the CFA is incredibly difficult. Much more difficult than it looks on paper. My DS is a solid 3 sport varsity athlete, and his scores were good, but he couldn't believe how hard it was. Especially how hard it was to run a mile after you taxed the rest of your body. So, building an athletic foundation now will really help you.