Sports are great, but I think a more recent challenge would be more appropriate especially if your topic is failing to make a varsity sports team. Have you experienced any failures in college? I think I've done pretty well in the past 3 years but I definitely have plenty of failures and challenges.
Yeah I've done well academically as well. Most of my failures would be in my research. I spent almost half a year wasting time and grant money studying something that proved to be fruitless. Some other challenges I have faced are public speaking and dealing with my phobia of blood (thankfully I overcame this one). What kind of extracurriculars do you do? I would look into those.