Workout Of The Week: Brad Hudson’s 1-2-3-2-1 Fartlek

A few years ago I had the privilege of collaborating with Brad Hudson on a training book entitled Run Faster from the 5K to the Marathon. Brad was a top runner back in his day, with a couple of 2:13 marathons on his resume, and is now a top coach based in Boulder, Colorado.

I learned a lot from working with Brad. One of the things I learned was the value of multi-pace workouts. Most workouts target one or, at most, two paces. For example,  your typical long run is done at a single, steady pace. Your typical interval workout targets two paces: a fast interval pace and a slow warmup, recovery, and cooldown pace. But there’s good reason to perform some workouts that target three or more different paces.

Such workouts can be used to provide a small dose of running at several intensity levels when that’s what fits best into a given week of training, to train your ability to “change gears” during a hard effort, and to provide a literal change of pace in your training that is mentally refreshing yet also physically productive.

Time-Based and Road Friendly

Brad’s 1-2-3-2-1 workout is perhaps my favorite multi-pace workout amongst the several he taught me. It is run by time rather than distance and is therefore conducive to being done on the roads, which is what it’s really designed for. The numbers in the name of the workout represent minutes. After warming up with some easy running you get down to business by running one minute at roughly your 5K race pace. Then you jog for one minute. Then you run for two minutes at roughly your 10K race pace. Then you jog for two minutes. Then you run for three minutes at roughly your half-marathon race pace. Then you jog for three minutes. Having “climbed the pyramid”, you now descend on the other side and finally cool down.

When you start this workout for the first time it seems like it’s going to be easy, but, trust me, it gets harder and harder. It gets especially hard if you run too aggressively out of the gate. One minute is not a long time to run at 5K pace, so it’s tempting to run faster. But one minute is not a long time to recover from such an effort, either, so you can quickly dig a hole of oxygen debt that you can’t climb out of if you run the first fast minute too fast.

One thing this workout teaches you, and another reason it’s so demanding, is that there’s not a huge difference between 5K and 10K and half-marathon race pace for the typical trained runner. For example, suppose you’re a runner with a 5K PR of 20:00. So your 5K race pace is 6:26 per mile. According to McMillan’s Running Calculator, in this case your 10K race pace is 6:41 per mile (only 15 seconds per mile slower than your 5K pace) and your half marathon pace is 7:04 per mile (only 38 seconds per mile slower than your 5K pace and 23 seconds per mile slower than your 10K pace).

What this means in the context of a 1-2-3-2-1 workout is that you have to run two minutes at a pace that’s only slightly slower than the pace you have to sustain for just one minute and three minutes at a pace that’s only a notch or two slower than the pace you have to sustain for two minutes. That said, the paces are different, and in doing the workout you will want to be conscientious about running at three distinct paces in the segments of different durations. The first time I did this workout I made the mistake of running all of the fast segments at more or less the same pace, probably because I was so unaccustomed to doing multi-pace workouts.

Moderate and Advanced Option

The 1-2-3-2-1 format is actually the moderate version of this workout. Brad’s top runners more often do a tougher 1-2-3-2-1-2-3-2-1 version of the workout. Do the moderate version when you’re in base training or just want a secondary high-intensity training stimulus to supplement your primary high-intensity workout of a given week. Do the harder version as your primary high-intensity workout of the week when you’re already in pretty good shape.

Because even the hard version of this workout is relatively short (17 minutes of fast running, 17 minutes of recovery running), it makes sense to pad it with a long warmup and a long cooldown to enhance the endurance-testing dimension of the session. This is not a focused workout designed to maximize your ability to run at a specific pace. It is a balanced workout designed to give you a little of everything, and adding a long warmup and a long cooldown (12 to 24 minutes for each) gives it a little more of the thing (an endurance challenge) it is otherwise lacking.

Updated from article originally published April 2016.