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Polarized running; the 80/20 rules unraffled

I often get asked how the model of 80/20 running, also known as polarized training, applies to amateur runners. Here’s my take.

What is the 80/20 model?

For those of you who have never heard of it, it’s the idea that all runners – whether elite or amateur – should do roughly 80% of their training sessions at an easy pace and 20% at a fast pace. So if you run 4-5 times per week, one session should be hard and the rest easy.

Coaches and scientists often divide training intensity in 5 zones:
  • Zone 1: easy running ~ being able to talk comfortably

  • Zone 2: moderate running ~you can talk, but it may not be so comfortable

  • Zone 3: sub-threshold ~the pace you can hold in a race for 2-3 hours

  • Zone 4: threshold ~the pace you can hold in a one-hour race

  • Zone 5: faster running ~ you can’t hold this pace for longer than 30-40 minutes in a race

The proponents of the 80/20 model claim that easy sessions should be done in zone 1 and maybe a bit of zone 2. The fast sessions should be done in zone 4 or 5. We should try to avoid the in-between zone 3 (sub-threshold running) which is considered tiresome, but not so effective.

This training principle is based on a thorough analysis of the training of world class distance athletes by scientist Stephen Seiler. The idea is that if we want to improve ourselves, we should all do what elites do, which is do a lot of easy running and a bit of fast running and not much in between.

What can we learn from this?

To be able to give a good answer to that question, I have read almost every scientific article analysing the training of elite runners, as well as every article dealing with the 80/20 model of training. Although unfortunately part of the research is flawed, there are definitely some important take aways.

  1. Improvement comes mostly from two things: lots of easy mileage and some hard workouts

  2. Runners should have intensity discipline if they want to improve

  3. Do your hard workouts in the ‘right’ intensity zone

It’s true that most elites do a LOT of easy running. They often do 10-12 running sessions per week, with only 2 or 3 of those sessions being hard. In terms of mileage, I’ve made my own calculation and lots of elite runners that I know or have coached, do around 15% of their mileage at a high intensity, which I consider zone 3, 4 and 5 taken together. Those who run 180km per week, do around 25 – 30km of it at high intensity (marathon pace or faster) and the rest of it at an easy pace.

1. Benefits of easy training vs. hard workouts

Doing lots of easy mileage has many benefits. For example, it helps to build mitochondria in our muscles, which are our super important energy factories. Easy mileage also increases our vascularisation (it creates more small blood vessels in our muscles) and stimulates our fat oxidation. In short; easy running helps to make us a more efficient runner, because our oxygen transport and energy producing system gets better.

Because of these adaptations, lots of easy training helps our body to recover from and respond to the more strenuous workouts. In other words: elites can handle very heavy workouts (and recover from it) partly because of all the easy running they do. That’s good to understand.

Apart from easy mileage, we also need hard workouts. These workouts have a slightly different effect than the easy running. For example, they make our mitochondria work in a more efficient way.

2. Intensity discipline

This refers to the fact that elites train hard when they have to, and easy when they have to. They don’t go out of the door for an easy run, and then turn it into a moderate run. Simply put: they train what they HAVE to do, not what they LIKE to do. This means that they keep most of their mileage easy, so that they can do a lot of it, and still enable their body to recover. So that when the next workout comes, they are ready to nail it.

Of course, it’s not just elites who have intensity discipline. Some amateur runners have it as well, but there’s a lot more variation among them. If you’re one of those runners who often turns easy runs into moderate or hard runs, this is an important lesson to learn. Don’t get stuck doing too many ‘in between runs’, sessions that are not very easy, and not very hard. Because you’re probably missing out on the most important training effects.

3. Right intensity zone

This is where the 80/20 model gets it wrong, in my believe, by claiming that we should avoid zone 3. Analysis of the training of elite runners shows that the middle zone (zone 3) is used just as much as zone 4 or 5 – and in some parts of the year even more. An example of a zone 3 training session is a 10 mile tempo. Or an interval session of 4 x 5km.

The reality is that elite runners use all their intensity zones. That being said, it does matter what zone you’re training in. If you’re preparing for a half marathon, it doesn’t make sense to do most of your hard workouts in zone 5 (for example 10 x 400m). You want to focus more one sessions in zone 3 and 4. On the other hand, a runner who has a 5km race in a few weeks time, should probably do a bit more workouts in zone 5. In another column I will go into detail about this.

Now, the key question: should amateurs do 80% of their sessions easy?

The answer to this is no. I have no reason, not from practice, nor from science, to believe this to be true. If you are doing 4 sessions per week, it can work perfectly well to turn this into 2 easy runs and 2 hard workouts.

Of course, every person is different. And we change throughout our lives. When I was 16 years old, I did 3 hard workouts and one easy run per week. So I used the 25/75 method. If I do the same now – with 31 years of training in my legs, including 15 years of very hard training – I will get injured and overtrained. So for some runners, doing just one workout per week might be the right thing to do. But for the majority of amateurs, this is not a rule to stick by.

Then what about doing 80% of your mileage (rather than sessions) easy? To be honest, that comes closer to wh

at we see in reality. Most amateur runners do anything between 15-30% of their mileage at high intensity. More than elite runners, but that is simply because they make less easy mileage. Again, this is not a rule to live by, what if you’re consistently doing a lot more than 20% of your mileage at high intensity, and you’re not improving, this is something you want to look at.

Did you find this column interesting and are you hungry for more knowledge? Maybe you should join our Kenya Camp, because there’s a lot more to learn there.

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