" Also, what's the point of reducing rest until you're basically running a race with 15 second breaks every 1000m?"
Who the hell said anything about 15 second breaks? I said 5 x 1k at 3:00 with 1:00 breaks, and that is at the end of a long progression, a season long progression starting with 3:00 rest. I said nothing about 15 second breaks anywhere.
The point is this:
What is the purpose of training? To prepare to race. The less rest between repeats the more it mimics a race. That is the fundamental strategy behind interval training, which has been lost over time. To break up a race into manageable segments. INTERVAL refers to the rest. Interval training is all about the rest. You run a 1000, you rest, you repeat. To make the workout harder you reduce the rest. I know the science, I have a BS in Ex. Sci, but that doesn't mean shit. My dog could get a BS in Ex. Sci. The science simply explains the results, it explains what should already be known and what should already be learned through actual training, the trial and error experimentation of one runner. Yes of course you should run shorter and faster reps from time to time and yes of course you run longer and slightly slower workouts, but the bulk of your training should be around race pace. Anything else just isn't logical. Each week you should do something at race pace. Your other workout is either a little above or below race pace.
If you can't run 5 x 1k in 3:00 with 1:00 rest then how in the hell are you going to run 15:00 in a race? Luck? Heart? BS. It's not a workout you should do every week, but it is a workout, perhaps a final workout, that you should be able to do. Others could be 2 miles at 5k pace OR 2 x 2500 at 5k pace. If you can do either of those two a week before your 5k race you should be fine. Again if you can't run 2 miles in practice at your planned 5k pace then you better come up with another plan. Likewise, if you can't run 2 x 2500 (400-800m rest) at planned 5k pace in practice then you better come up with another plan.
How is Ritz going to go through half-way in 1:04-05 if he doesn't do it in training? That's not racing, thats smart training to prepare to race.
Alan