wow those are amazing times! incredible, do u come in the top for your age bracket? so you also haven't ran a marathon.. thats a bit rare isn't it? alot of people here are aiming to do marathons right away.. i guess it applies everywhere? but im sure you would have no problem running one, right? if you can have those times in 21k, then you for sure are strong enough to run marathon right? training for the endurance needed won't be that difficult compared to what it took to get to where you are now already.. at least thats how im thinking about it..
the book is great so far! first running book, also heard about murakami's running book.. passed off buying the non-fiction running books since there are so many articles online about running that give good tips, i wonder if its worth buying a running book, scanning thru them give the impression they're basic.. i dont know