OK so the next 3 weeks I'm thinking of doubling 5 or 6 days of the week. Workout days will be 3-4 miles of an additional run and non workout recovery days will be a split of 5/6 or 5/7 or 6/6 or something. Hope I see some improvement from this new stimulus... also I havent done hill reps in forever so hope that helps too!
I think that for most people starting out with doubles for the first time at 5-6 miles might be a bit much, and most likely will leave you tired for your main training and racing in the near term.
If you're really going to jump in to doubling with secondary runs that long, make sure you run them pretty darn easy.
Like I said, I've doubled before and was running 3 or 4 doubles a week (3-5 miles), just in the past month I haven't been so good about it. I'm also thinking about doing my main session on workout days in the morning just to get it out of the way even if it means running slower, and then doing an easy few miles hours later.
I was thinking about cutting back on the doubles the week before my race. I'm going to run them very easy.