What Is the 80/20 Rule in Running?

Runners often swear by the 80/20 rule when planning their training, but that has nothing to do with Pareto principle of the same name. Let’s talk about where the 80/20 idea comes from, how to implement it, and when it is and isn’t a good idea to train this way.

What is the 80/20 rule for running?

In short, it’s the idea that 80% of your running should be low intensity, and only 20% medium or high intensity. Recreational runners (like you and me) often run closer to a 50/50 split. The 80/20 rule suggests that we should do some of these runs faster and really slow them down to achieve better training balance.

The 80/20 rule was popularized in a 2014 book, 80/20 runningby Matt Fitzgerald. Fitzgerald, in turn, based his recommendations on research by Stephen Seilerwho found that elite athletes participating in a variety of endurance sports, including running, cycling, and cross-country skiing, performed about 80 percent of their workouts at intensities far lower than they would ever use in racing. In other words: to train your body to go fast, you need to cover many miles while driving slowly. This is similar to the idea of ​​”polarized training,” meaning you stick to the extremes: either working very easy or working very hard, rather than spending a lot of time in between.

Note that 80/20 here only refers to how you split your training: 80% easy versus 20% hard. It is not the Pareto principle, which states that 80% of your results come from 20% of your… whatever. (80% of sales coming from 20% of customers, 80% of your needs satisfied by 20% of the goods you ownetc.) In running, there is only one result: your running time. So the question is how to allocate your training time. 80% easy and 20% hard is the balance that, Fitzgerald and Seidler would say, will get you the best race times.

What constitutes low intensity running?

If you have been pay attention to the “zone 2” trendyou probably think you should be in zone 2 (undoubtedly 60-70% of your maximum heart rate) for 80% of your workout. And you know what? This will get you close enough. Go for it.

But the definitions most often used in scientific research are not based solely on heart rate. Some of them use measurements that we cannot easily measure on our own. Go ahead and try to keep your blood lactate below 2 millimoles per liter.

What is more useful – and still supported by research – is to use VT1, the “first ventilatory threshold”. It’s a fancy word for what old bosses will call the “speaking test.” If you can carry on a conversation without taking extra breaths mid-sentence, you are below VT1. This is what 80% of your training should look like.

I know that’s not enough information for the more data-conscious among you, so I’ll note that Fitzgerald reported in his book that this level is often around 77% to 79% of elite maximum heart rate. The exact number can vary from person to person, and heart rate numbers are never completely objective, as they can be affected by heat and stress, among other things. But as a gut check, 77% of my known and tested max puts me around 153, which matches surprisingly well with what I consider my easy pace: I try to stay in the 150s for my easy runs.

Combining this information, it turns out that we can go a little higher than “zone 2” and still maintain the right intensity for the 80% portion of our 80/20 race, as long as it feels really easy. If you want, you can customize your zones on your running watch so that you have a zone that maxes out at around 77%. (It might even make more sense for it to be zone 3 rather than zone 2.) Or if you want to round that number to get an easy-to-remember rule of thumb, you can keep 80% of your run below 80% of your (true) maximum heart rate and you will be on the right track.

How to train with the 80/20 rule

Before we can divide our training, we need to decide how we measure our training. Are we aiming for easy runs to make up 80% of our workouts? 80% of our miles? 80% of our total training time?

Fitzgerald, in his book, counted the minutes according to easy, moderate and difficult intensity levels. But if you do an interval run, it counts the intervals And recovery between them as part of your more intense intensity work. (A cooldown after these intervals would be considered low intensity, however.)

So you can do the same. This would also allow you to think in terms of kilometers or sessions. If you do one hard run for every four easy runs, you’re still doing 80/20 (as long as those runs have roughly similar mileage).

How important is it to follow the 80/20 rule?

Even though it’s called a “rule”, it’s not something you duty follow. It’s just a way of training that aligns with what many elite athletes do. Research has also shown that recreational runners can benefit, but that doesn’t mean it’s the only way to train.

Seidler, the researcher, even told Fitzgerald, the author, that if he could only train twice a week, he would do a mix of harder and easier work over the two sessions. Research on competitive recreational runners found that a 77/23 split and a 46/54 split both resulted in slight improvements in 10K times, and that the difference between the groups was not statistically significant. That said, these folks had 10k times (that’s a 6.2 mile run) in under 40 minutes to start with, so they were pretty fast to begin with, compared to a lot of beginner runners.

Meanwhile, plenty of other research shows that casual runners can improve with almost any type of training and that increasing your total mileage (measured in miles per week) is helpful for improving your fitness and running times.

The essentials

If you’re a runner with a lot of room for improvement (which is a lot of us beginner, intermediate, and casual runners), you don’t necessarily have to slow 80% of your runs to a crawl. You can use any speaking pace that works for you, even if your watch says it’s zone 3. And since increasing mileage is usually part of improving as a runner, it may make more sense to think about it. addition easy miles, rather than turning your hard miles into easy miles.