I know that I will never be or want to be an endurance runner - I don't have the time, the body type and I certianly don't have the desire. I know from research, observation and personal experience that big distance running is bad for your body on several levels.... but...

I really want to run a regional marathon in December. I've always wanted to and for the first time in my life I can (with some additional training). I know it is a little petty to want to do it just as a notch in my belt, but really want to unless convinced that the damage it'll do is too great.

I've always hated running, for years because I couldn't run (too fat) and recently, I've been miserable when running but accepted it as a need tool chasing weight-loss and fitness goals.

I actually enjoyed running for the first time the other day about mile 10 of a tough mudder, so am not so worried about the training being miserable.

How bad for you is a marathon and the training for it - considering it is a serious, but not overwhelming, step up from my current running and considering that it is likely a one-time event?