In Running, Slow is the New Fast

via infomatique

via infomatique

It can be hard running slow sometimes (I’m not calling out slow runners–I am a slow runner). I’m referring to that day on your training plan that calls for you to purposefully run slower than you normally would. We’ve all been there. That little box on the calendar reads “5 miles – Easy”. You are capable of so much more than easy. What should you do? Well, you ignore the word easy and blast out those miles pretty close to race pace.

Hey, I get it. It’s hard to slow down when your brain is telling you that the only way to get faster is to run faster on every run. On top of that, a slow run is just junk miles and junk miles are a waste. Plus, you can’t let your friend/neighbor/spouse run faster than you did. No, you need to blast out a PR on every run: training run, race, it doesn’t matter. Run fast!

Why Run Slow?

If that’s you, you are doing it all wrong. It’s been proven that running slow is vitally important while in training. There are a number of reasons to take it easy on your next easy day.


An easy run allows you to get your miles in, but it will also keep you fresh for your next SOS (I borrowed this from the Hansons–“Something of Substance”) run like a speed or tempo workout. If you blast out a quick 5 miles, the odds of being fully prepared for tomorrow’s tempo run are slim. If you are running 5 or 6 days a week, there is very little time to rest. Your easy runs should be used to help recover before the SOS workout.


There are essentially two sources of energy during your run: fats and carbs. As a long distance runner, your primary source of fuel is fat. Don’t worry, even if you are sitting at 5% body fat, there are still plenty of fat deposits to burn. However, once you start increasing your speed, your body stops burning the fat deposits and starts eating up your carbs.  This switch from burning fats to carbs occurs somewhere in the 50-60% range of your VO2 max.  You only have a couple of hours worth of energy in the form of carbs–once those are gone you are done. What was that noise?  That was you hitting the wall.

There is hope. That 50-60% threshold range is right around where your easy runs should be. By keeping those easy runs easy, you are actually training this threshold. Essentially, you are teaching your body to stay in that fat-burning zone longer which may prevent you from hitting that wall.

Train like the Elites

The elites have already figured it out. They know that easy runs are vital to faster finishes.  In his book Run: The Mind-Body Method of Running by Feel, Matt Fitzgerald recounts a story about the 1972 Olympic Marathon gold medalist Frank Shorter. Frank was notorious for running his slow runs slow. Really slow. He would run them so slow that you and I would be able to keep up with him (well, maybe not that slow). Yet, the next day he would hit the track and blast out whatever hard workout he had planned.  Fitzgerald writes, “That was one of Frank Shorter’s secrets…running his easy days very easy, and his hard days extremely hard. A simple concept, but so hard to carry out for some reason. Most of us make the mistake of going medium-hard all the time”.

How Slow Should You Go

There really isn’t a set number–it’s different for everyone.  Using the McMillan Running Calculator, I mocked up some paces. I put in that I wanted to run a half marathon in 1:45. To do that, I would need to sustain a pace of 8:01. Here are the paces McMillan says I should hit for my easy runs during training:

Easy Run Type Pace
 Recovery Run 10:35 – 11:20
 Long Run
 Easy Run

As you can see, depending on the type of easy run, I should be running anywhere from 1.5 to 3 minutes slower than my race pace.

I know the thought of running 3 minutes slower than usual sounds awful. Plus, what will your fast friends think of you? But remember, training is only meant for one thing: to get you ready for the big show. If running that slow will better prepare you for a PR in your next run, isn’t it worth it?

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Chris Gibson