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Run slow to become fast – the 80/20 rule

Running (general)
Background information

Running slow is the secret to running fast. I know, that sounds like a contradiction, but there is actually a very logical reason behind it. So, let’s explore why you should run slow to become fast.

The concept of running slowly has a lot of different names: 80/20 running, low heart rate training, Maffetone Method, pyramid training and polarized training. I probably forget a few names, but it’s not the name that’s important, it’s the concept.

Doing it all wrong

I don’t know how you run, but to be honest, when I started running – in my first running life – I had no idea what I was doing. I just ran. Most people did at the end of the eighties, beginning of the nineties of the last century. I looked at a couple of training schedules, followed even some of them, but they only told me how many kilometers or how many minutes I had to run. Not how fast or how slow.

My personal record on the 10 kilometers in those days was 40 minutes and 8 seconds. If I went out for a training run, I would run 10k in 42 minutes, sometimes 44. Never slower. Don’t ask me anything about my heart rate in those days. I had no heart rate monitor, and smart watches didn’t exist. Only later I got a Polar which measured my heart rate. I would look at it, but never do anything with it.

How to train effectively

When I started my second running life, now almost 2 years ago, I decided I wanted to know more about running, about training. I wanted to do it right this time. But above all, I wanted to run without getting injured. So I decided to listen to podcasts and read all the books I could find about how to train.

What kept coming back was the advice to run hard on hard days and run slow on easy days, followed by the warning that most people run too hard on easy days and too slow on hard days. I’ve studied lots of anatomy in the last couple of years, but even without that the reason behind this concept is logical; your body needs time to recover. Taking it easy means recovering. Taking time to recover properly means less injuries. Less injuries means more training hours, because you’re not sidelined.

Balance hard and easy work-outs

To put it very simply: training doesn’t make you stronger. Rest does, but only because you workout. Training is damaging your body. Resting is giving your body the time to repair the damage and to make your body stronger to prevent it getting damaged again. But what happens if we don’t rest enough? Simple: we break down our body.

Look at it this way: if you have a little wall consisting of 10 bricks and you take 2 breaks off every time, and only put 1 brick back, pretty soon you don’t have a wall anymore. Same for your body. If you damage it more than you’re repairing it, you’re getting weaker instead of stronger.

RELATED: Training is damaging your body and that’s good

What you have to do is find the balance between training hard and taking it easy. But what is that balance? The American Professor of Sport Science Stephen Seiler studied the training schedules of the best athletes in the world and discovered that they train 80 percent easy and 20 percent hard.

'Training is damaging your body. Resting is giving your body the time to repair the damage and to make your body stronger to prevent it getting damaged again'

John Kraijenbrink

What is easy, what is hard?

Which brings us to the next question; what is easy and what is hard? The answer depends on how complicated you want to make it. Let’s start simple. An easy run is a run in which you can comfortably hold a conversation, without getting out of breath. Hard is when you’re gasping for breath

If you want to make it more complicated and more precise, you can work with heart rate zones. Most heart rate monitors work with 5 zones. Training in heart rate zone 1 and 2 classifies as easy, training in zone 4 and 5 classifies as hard. Zone 3 falls somewhere in the middle. There is a whole discussion among sport scientists if you should or should not also workout in zone 3, but we leave that for another blog post.

Using heart rate zones

Most heart rate monitors/smart watches will set the heart rate zones for you, based on your maximal and/or your threshold heart rate they detect during your training. If yours doesn’t, there is again a hard way and an easy way to determine your heart rate zones.

The easy way is by using your maximum heart rate, and the easy way to do that is by using your age to base your maximum heart rate on. Simply calculate 220 minus your age to find your maximum heart rate. In my case 220 – 50 = 170. I admit, it’s a very inaccurate method – my maximum heart rate is still 192 – but it can work.

Now you can determine your heart rate zones:

  • Zone 1 = 50 to 60% of your maximum heart rate
  • Zone 2 = 60 to 70% of your maximum heart rate
  • Zone 3 = 70 to 80% of your maximum heart rate
  • Zone 4 = 80 to 90% of your maximum heart rate
  • Zone 5 = 90 to 100% of your maximum heart rate

If you find online, or in exercise books, percentages that are slightly different, don’t worry. It’s all more or less. It’s a guideline. Your body doesn’t suddenly start to function differently, because your heart is beating 2 beats per minute faster.

Lactate Threshold Test

If you want to know your heart rate zones more precisely, you have to do a lactate threshold test. For the best result you have to go to a specialized lab. However you can do a field test as well. That will give you a good indication. You’ll find an example of a field test in the blog post What Lactate Threshold is and why it matters. What you’re looking for is the heart rate that corresponds with your Lactate Threshold.

Okay, let’s look at the heart rate zones one more time, but this time we’ll give them a name or function, whatever you want to call it:

  • Zone 1 is Warming-up
  • Zone 2 is Easy (pace)
  • Zone 3 is Aerobic
  • Zone 4 is Threshold
  • Zone 5 is Maximum

As you see Zone 4 is Threshold or Lactate Threshold. Which corresponds to 80 percent of your maximum heart rate, as we’ve seen above. Now you can determine your heart rate zones:

  • Zone 1 = from (Threshold Heart Rate divided by 80 times 50) to (Threshold Heart Rate divided by 80 times 60)
  • Zone 2 = from (Threshold Heart Rate divided by 80 times 60) to (Threshold Heart Rate divided by 80 times 70)
  • Zone 3 = from (Threshold Heart Rate divided by 80 times 70) to Threshold Heart Rate
  • Zone 4 = from Threshold Heart Rate to (Threshold Heart Rate divided by 80 times 90)
  • Zone 5 = from (Threshold Heart Rate divided by 80 times 90) to (Threshold Heart Rate divided by 90 times 100)

In my case, for example, I have a lactate threshold heart rate of 167. Which means:
Zone 1 is from; 167 / 80 = 2.0875 * 50 = 104, to; 167 / 80 * 60 = 2.0875 * 50 = 125.

Using this method my maximum heart rate is strangely high. Just do the math: 167 / 80 = 2.0875 * 100 = 209, but as I said before, it’s all an indication, a guideline. It doesn’t come down on a few heart beats more or less.


How it works

Okay, now you know what is hard and what is easy, but how do you apply this knowledge? Simple: 80 percent of your runs should be easy, meaning in heart rate zone 1 and 2, and only 20 percent of your runs should be in heart rate zone 4 and 5.

Let’s say you’re running 5 times a week. In that case you should do 4 training sessions at an easy pace and 1 training session at a hard pace. That way you give your body enough input to get stronger and fitter, but at the same time you give your body enough time to recover from all your work-outs.

Just to be sure: a training session is either easy or hard. So if you run easy for 80 percent of a training session (heart rate zone 2) and hard for 20 percent (heart rate zone 4) it counts as a hard session. Easy is easy, is heart rate zone 1 and/or 2 for the whole session.

Yes, you can train hard

Now we’re not professionals, at least I am not. We don’t train 2 to 3 times a day. Which means, according to the Dutch human performance scientist Jim van den Berg, that we can use these percentages loosely. It doesn’t have to be strictly 80/20. 70/30 is good as well. As long as it doesn’t become 60/40 or even 50/50.

Having said that, keep in mind that physical stress and mental stress is the same for your nervous system. It’s this system we have to give a break. We’re aiming for 80 percent easy to give our body enough time to recover. If you have a stressful job, you are putting your body under a lot of stress as well. In that case you might even want to aim for 90 percent of easy training sessions and only 10 percent of hard ones.

Of course you can have a more intense week. Let’s say you do have a week of 50 percent hard and 50 percent easy. In that case make sure to follow it up by an easy week. It is actually always good to train in blocks instead of focusing too much on fitting everything in a week, but that’s for another blog post.

Low heart rate training is frustrating

Last but not least; training in zone 2 can be very frustrating in the beginning. Your body has to get used to it. In the beginning you might be walking more than you’re running. I know I was.

Over time you will notice that you can run faster and faster with a low heart rate. This is super beneficial, as you will burn more fat and less carbohydrates at a lower heart rate, which means you can run for longer periods of time. But that’s just a positive side effect. The main thing behind the idea to run slow is that you give your body enough time to recover from all the work-outs you do. That way you become stronger, fitter and prevent injuries.

That’s it. Keep running (slow).

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