It's possible, however adding a new sports commitment while also planning to expand your clinical hours at the same time seems like a recipe for academic slippage.
That said, not everything needs to boil down to "will this look good on my med school application." You'll likely never get another chance in your life to do something like join the cross country team. If you want to do it, then do it, and just hold off on obtaining clinical hours until you're confident that you can handle your classes along with this first new time commitment. If you wind up not getting enough clinical hours you can always take a gap year. Many students wind up needing to do that anyways, and come out with a stronger app because of it.
