That's intriguing, Rabbit.

I know nothing from nothing. But I always thought that intervals are really beneficial for building aerobic capacity no matter what your "league." All the training plans I read online or in magazines include intervals, and it really seems like they've been helpful to me. Even though neither intervals nor anything short of rocket-powered shoes will ever make me "fast" in objective terms.

I think the way to avoid hurting yourself doing speedwork is the same way to avoid hurting yourself doing anything else: form first. But again, I know nothing.

The other thing I've been curious about is the general rule that says not to increase mileage by over 10% per week. (Hal Higdon actually says that more fit runners can take that up to 20%, but conservative is good I think.) Do you all increase the distance of your long run by 10% per week... or do you increase your total weekly mileage by 10%, which could mean loading all or most of the increase into the long run?