In high school I had a coach who liked doing this track workout where he would blow a whistle to indicate a change in pace (i.e. tweet = run fast, tweet again = slow down). Only he knew how long each rep was going to be (ugh, that was awful! We never knew if we'd be running hard for 1 minute or 5!).
Or my college coach, who is famous for the boil-simmer-boil workout (you should have seen the extreme confusion on our faces the day he started the workout by saying in his Boston accent, "You know how when you're cooking pasta and the water boils?")
And hill repeats - oh hill repeats - another coach thought they were God's gift to running. It seemed like everything we did involved running uphill at varying paces.
But despite each coach's specific preferences, some workouts just keep showing up whether I'm running with Coach P., Jim, Bruce, or George in California, Boston, or DC.
One of these workouts is the 3K-1500m-1500m, or for those of you running on a track (or metrically challenged), 2 mile-mile-mile. In Boston we did this workout almost weekly. We ran at the Chestnut Hill Reservoir (3K around), or the Brookline Reservoir (15oom around). In DC we do it on a track, so it becomes 2 miles-mile-mile.
The purpose of this workout is to build your speed and endurance by maintaining a hard pace over an extended period of time. The first rep (the 3K or 2 mile) should be barely faster than your tempo pace. The purpose of this rep is to get you tired, but not I-need-to-lie-down kind of tired. When you finish the 2 mile you should feel like Hmm, that actually wasn't too bad. Don't go out too hard - trust me on this, you'll regret it.
Take a 1/2 mile or 5-6 minute jog recovery.
For the first mile, speed up a bit. Try to run it at least 10 seconds faster than your 2 mile pace. You will notice that as you run this mile your legs start to feel it. But, again, don't run so hard that you can't maintain an even pace through at least 2 reps.
Jog 1/2 mile for recovery.
By the time you start the last mile, you should feel fatigued but not spent. This simulates the way your legs feel towards the end of a race. As SpeedyKate so wisely said last night, You want to be at that point where you have to run faster to keep from slowing down. By the end of the second mile you should be tired and done.
If you're not too tired, or if you're training for something longer (i.e. a half or full marathon), do another mile.
For us mere mortals, the 3 reps is plenty! With a 10 minute warm-up and a 20 minute cool-down, this workout rounds out a solid 9 miles.