It is not uncommon for athletes to participate in multiple sports. Some people are involved in a few sports, some a lot, and some have done it all. Sports are mostly seasonal, so if you are a competitive person it is likely that you will compete year round playing a few different sports. Take a high-schooler who does football in the fall, basketball in the winter and track in the spring. Ask him what type of cross-training he does, he will mention all three sports. Football makes him powerful, basketball helps with his vertical jump, and track makes him faster. The sports work with each other to make him a more well rounded athlete.