i'll start off by saying that i completely agree with what malmo says. but one fact that you (or most of you) seem to leave out is that along with not focusing on long runs (at the expense of other training), running doubles, is NOT WORRYING about mileage. Simply put, what I have always gotten from everything i've read from malmo was that you should just run, twice a day, three times a day, one time a day, but just run, as much as your body will allow (and you need to be an objective listener too) and if you do that the mileage will take care of itself. Don't get caught up in the numbers game. That's just my 2 cents worth.