czechit

1) Is submitting the Athletic Supplement to the Common Application a commitment? Can you submit it if you think you'd like to participate in varsity sports in college but aren't sure? Do you have to be in contact with coaches before you submit it? Should I list all sports I have played here, even if I do not plan to continue them in college, and not in the activities section? What's the deal with this?

2) What exactly does "walking on" to a team mean? Do you have to be invited to try out? Do I have to do anything now, or can I just wait until I'm there to try to "walk on" to the team? How does this work?

I am thinking of doing track at a DIII school. My PR in the 800m is a 2:29 from sophomore year. I was injured junior year and missed most of the season, but I'm fine now and my coach is optimistic about this year. I am going to try to lower my time to about a 2:23.

njcentconf

The athletic supplement is not a commitment on anyone's part. Choose a school that meets your academic needs, and as soon as you are accepted go ahead and contact the coach to learn more about the team. Take a look at the school's roster and the times from last track season to see where you fit.
A 'walk on' is someone who is not supported by the coach during the application process. Since your sport is not a fall sport (unless you want to run cross country), you can wait until you get to school, but it would be good to contact the coach ahead of time so she/he knows you are interested.

keylyme

^^Actually, a walk-on is an athlete not on scholarship, but can be supported (and recruited) by the coach. Most DI sports now have several "recruited walk-on's" as they just don't have enough scholarships for all of the athlete's they want for various teams.