Hi Bob,
In true AN - spirit: I am so sorry to hear that you have to have surgery, but glad you have decided and are getting it done with!
I think you know my story about the Ironman I am registered for in August, and my worries with AN surgery, recovery, and fitness loss. I still havent gotten back to "training" at 3 weeks post-op, but I was able to go to the gym a bit this week and have to say was happily surprised that doing cardio not only felt more comfortable than I thought, but also seems to be improving extremely quickly. I still don't know what I will be capable of in terms of the race, but am hopeful at this point. My biggest concern was fatigue, but my energy came back quickly after 2 weeks. My 2 cents: take it easy until you feel really ready, your body will dictate rest for you and welcome it. I predict you'll find it will be easier than the doctors think to get back into activity and your race.
Good luck,
Laura