Why I run slow – Benefits of Slow Running

As you all know, I’m quite obsessed with slow running and since I am doing recovery week, I get to spend my “running” time writing about running. Today I thought about the benefits of slow running and what I’ve learned over the past year. Here we go:

I want to become better at running. As research has shown, the more you run the better one gets. This starts way back with Arthur Lydiard. So how can I run more? I noticed, that once I ran over one hour, three times per week, I felt tired afterwards and didn’t have too much energy left for the rest of the day. I did some research and read all the books I could get my hands on. This is what lead me to slow running.

It is actually quite simple. No matter what the plans are, be it to run a 5k or a marathon, we will need a good “aerobic” system. If I partake in a longer event, I have a higher need for aerobic energy. In a marathon, 2.5%1 come from the anaerobic system – in a 5k it is already around 16%1.

As the word “aerobic” suggests, it all relates to oxygen and having enough of it. When running “aerobically” it means there is enough oxygen for the body to do all the work. If not, I am running “anaerobically” and produce debt (which ends in a big fat wall). I do like the comparison Matt Fitzgerald uses in his book “Iron War”: burning matches!

Let’s assume, that unlike in real life, before we can produce any debt, or burn matches, we have to collect some first. Running aerobically, or easy or slow or whatever we call it, will achieve this.

For me the questions became: “If I run slow enough – can I run more?” and “Why should I want that?”

This is what I found out:

I need a better Engine – Better Blood, Muscles, more Energy and better conversion ratios

More Capillaries

Capillaries deliver oxygen and nutrients to the muscle tissue and take away waste. Slow running increases their number. This is also another benefit actually, as slow running speeds up recovery and repairs micro-tears caused by fast running.

Better Muscle Fibers

Slow Running increases the Myoglobin content (protein that binds the oxygen) in the muscles and therefore gives your muscles more oxygen.

Better and more Mitochondria

Mitochondria are inside the muscle cells and they are the ones that produce the needed energy (ATP). Slow running increases their number as well as their size.

Use more Fat for Fuel

In the 1930s “The Crossover Theory” was developed and later led to research on aerobic training in relation to fat burning.

“The Crossover Concept holds that during post-absorptive resting conditions, in muscle and at the whole body in general, fats are the major fuel sources. But, as exercise intensity increases, in working muscle there occurs a switch (Crossover) from dependence on fats to carbohydrate energy forms as fuel sources.”


Say what? It means the slower I run the more fat is burned and the faster I run the more carbs are burned! Why would I want to burn mainly fat? Well … I have enough fat with me at all times to last for a long time, but not enough carbs.

Let’s go back to the analogy of “matches”. If we say carbs are the matches I need to burn to light up my fat engine, what I want is that the one match ignites a hell of a signal fire and not just a tiny flame. Slow running will help to build a stockpile of fat burning enzymes so that I can run long with the use of only a couple of matches.

How to do it – super simple trick

If I don’t have a heart rate monitor, I like to use breathing in only through the nose. That will keep me aerobic!

1 (Gastin, P.B. (2001) Energy system interaction and relative contribution during maximal exercise. Sports Medicine 31, 725-741)


16 Replies to “Why I run slow – Benefits of Slow Running”

  1. The problem I found with the Heart Rate running I did was the investment in time I had to make, and then translating that into pace. In the ideal world I would do 60 – 90 minute slow run everyday and then regular pace work and long tempo runs on top of that. It’s a huge investment in time but it would definitely get results. May have to give this another go when I don’t have quite so many other obligations.
    Thanks for the post though.


    1. I find Matt Fitzgerald’s 80/20 sounds interesting for adding speed. It is backed by solid research. If I can just stick to only 20% medium and fast … I don’t mind the time as much if it means no injury and I am more productive after running anyhow.


  2. Nice! I used to wonder why you are so particular about slow running! I found it just amusing..but whew! there’s so much of science behind it! Quite interesting! 🙂


  3. Hi, I’ve never been a runner and I may just be too old to start now, but this is really interesting. I rather like the idea of slow running, though I had never given it any thought before your blog, so thank you for the informative post. Happy slow running.


    1. Thank you Barbara! You may just be old enough to get started and be wise enough to go about it injury free, because you are not trying to proof something to someone. Then, after a few years, you’ll catch up with everyone on their run out legs and grab all the age group awards! You’d be surprised to find out how many people run into old age (i.e. Fauja Singh, 103-Year-Old Marathon Runner). When I started I followed this guide: http://breakingmuscle.com/running/a-week-by-week-guide-to-becoming-a-runner-later-in-life-and-or-safely and my mom is about to start it as well! It seems to be infectious 🙂


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: