So here is a hypothetical. Last year I self-trained and ran 49.9 in the 400m. Right now I do some sprinting, some cross training, and low volume some easy running, and I can run 3 miles in, say, 20-flat (I'm a fairly big guy at 6-2, 180 pounds)
Is it possible to translate the 400m speed (maybe I can do 52-53 right now) into a sub-2:00 800m by only doing sprint workouts on the track and swimming for anything longer?
I'm looking for the easiest, most enjoyable route to breaking 2:00.