Pushing to the limit...

Have you ever thought about doing something that will push you to the limit?  I mean physically and mentally, maybe socially or spiritually.

Well, this month I would like to see if I can push myself, spiritually, socially, mentally and physically.  Some will be places that I haven't been, some will be places that I have been to and lost over the course of the years.

The questions is :  "What will do that?"