I ran the London marathon last year. this year (on Sunday in fact) I did a 20-miler fell race (huge amounts of climb, wading through streams, navigation - much harder than the marathon - and took me longer). It was awesome. and - although I swore it would be my last long race - I can't put the whole thing to bed. there's a little bit of me (and I admit I'm still on a post-race high) wondering if I could do something longer/harder. The 20 miler was unbelievably hard - I thought my ankles were going to give in. I thought I was going to cry and collapse as I crossed the line (I didn't).but it was amazing.
A year ago, when I kind of thought about maybe doing it, I thought that really it was nuts...but now my idea of what counts as "nuts" has shifted. but am I in danger of getting sucked into proper madness if I went for something else? is it like moving on to harder drugs? am I just looking for a bigger and better high? or have you done something bigger than a marathon and thought it was so good you'd recommend it?