Motivated, belligerent or just stupid?

A year ago my doctor told me that I had very little cartilage left in my right knee and that I should stop running or I would be in pain and eventually require knee replacement surgery. I took him fairly seriously and started biking and rowing instead of running.  It sucks, because running is one of the few things that comes easy to me.

During the past year, I have gone out and jogged a couple of 3 milers with Julie and had no pain.  Then I ran in two 5K races and again, no pain.  My thought is that it isn't a single day that hurts my knee.  It's the accumulated inflammation from logging hundreds of miles, especially hilly ones, training for a race. These races were great because I didn't train at all. Zip.

So, apply a bit of logic.  If 5K with no training is easy and doesn't hurt, then the 13 miles of a half marathon can't be that much worse.  Right?

Julie talked me into going out and doing a 6 mile test.  I did, and while I can tell I haven't been running, my knee was fine.  I went ahead and signed up for the Park City Half Marathon in three weeks (Aug 17th).

The challenge is that using my logic, I shouldn't train at all.  I have always thought that every time you double the mileage, the effort and problems increase by a factor of four.  Doing the math, going from a simple, fast 5K to a half marathon should only be 16 times as hard.  I tried to remember the last time I did any form of exercise for two straight hours.  I think it was the Jupiter Peak Steeplechase two years ago.

If I blow up along the way and don't finish, at least I won't have wasted a lot of time training!