So I'm finally trying to follow a formal training plan, leading up to my next half-marathon, in hope of breaking 2 hours. It's from the Runner's World website; I put in recent 10k time, current weekly mileage, etc. The plan is pretty much what I was doing anyway, except for one thing-- it has me doing easy runs and long runs at a 10:30/mile pace. I never run that slow. I can't even when I try! My usual easy/long pace is somewhere between 9:30 and 9:45 per mile, depending on the weather and the hilliness of the day's route and how I feel...

Why does this plan have me running so slow? Will running as slow as I possibly can somehow make me faster? I don't get it... Any wisdom out there?