That doesn't sound like a good idea. Among other things, it could easily be misinterpreted. Surely, there are other friends, family and former coaches that could go on the list.
When you block a person, they can no longer invite you to a private message or post to your profile wall. Replies and comments they make will be collapsed/hidden by default. Finally, you'll never receive email notifications about content they create or likes they designate for your content.
Note: if you proceed, you will no longer be following .