How fartlek running can make you a better runner

Fartlek running. Not everyone likes doing it, not everyone knows how to do it, but fartlek running is one of the easiest ways for all runners to improve.

Why? Because fartlek running works on both your aerobic and your lactate endurance. It helps you run longer and by building your lactate endurance helps you to run faster for longer.

From beginners to experienced running, everyone should include a fartlek run in their weekly sessions.

How to do fartlek running

The thing that a lot of people don’t like about fartlek running is that it is unstructured. When you do a fartlek session you aren’t given distances or pace, which some people find confusing. It’s much easier to do something if you are told exactly how to do it!

However, if you remember that the word fartlek means speed-play and is really just playing around with speed for a set time that can help. Don’t think of it as ‘sprint’ then slow recovery jog, like you may do with 200m, 400m  or 800m repeat, but rather just speeding up and slowing down as you feel like it. Almost like a car travelling through a busy town center. You may be going slow for a bit and then all of a sudden speed up as the traffic clears, only to slow again for the traffic lights followed by steady drive. The idea is to be moving continuously but changing your pace regularly.

As for the distances you should play with use your environment. If you are running in an urban area use the street lamps, dustbins, houses or traffic signs as your markers. If you are in a park or a more rural area use the trees, bushes, benches or gates.

How to add fartlek running to your training

The best thing about fartlek running is that you don’t need to go to a track, measure any distances or worry about time. Just choose one of your regular runs and add a fartlek section to it.

If you are a newer runner or have not done speed or interval sessions before then just add a 5-10 minute section into one of your shorter runs where you play around with the speed. Warm up for the first mile or so by running easy and then start your fartlek running. Start with a 5 minute section and then run easy for the rest of your run. Once you get used to fartlek running you can slowly increase the time you do them to up to 15 minutes. Starting with a 5 minute section has lots of benefits for your endurance and your feel for pace.

For more experienced runners who are used to these types of sessions you can start with a 10 minute fartlek section and increase it to 20 minutes. For those who have been running longer distances for a few years the fartlek section can be increased to as long as 45 minutes.

Fartlek running can be part of your ongoing training. It’s something that is beneficial even if you are not training for a specific event

How to make fartlek running fun

I find fartlek runs fun, they really bring out the kid in me. Playing around with speed makes me think of being in the playground playing It or British Bulldog (without the violence!). Add some rain and some big puddles to jump over and I’m in my element.

But for those of you who find them hard work then try running them with a friend. You can each call out ‘faster’, ‘slower’, ‘change pace’ and just play around with it. It can be a silent change where one of you sets the pace and the other has to keep up with the changes. And you should take turns during the run on who sets the pace and changes, maybe a couple of minutes each and keep swapping.

However you do it I hope you have fun playing around with speed and improving your endurance!

originally posted 8 March 2017, updated 8 August 2020

Leave a Comment


  • Confessions of A Mother Runner

    I like the unstructured aspect of this type of running. I do it often without really planning to

    • Nicola

      That’s what I like too but I know some people find it really hard!

  • Rachel

    Are you reading my training plan? I have fartleks tomorrow! 🙂 I personally hate the unstructured run but you make it sound really fun when you compare it to driving through a city center and then having space to drive fast.

    • Nicola

      I hope the car comparison helps!

  • Christyruns

    I use telephone or electric poles for fartleks, I used to hate how unstructured they were too, but I have learned to enjoy them more

    • Nicola

      They can take time to get used to, especially if you are following a training plan where everything else is written out in great detail.

  • Runwright

    Great post. I learned this a while back when I was training for a run and wanted to improve. Sad part is I don’t incorporate fartleks as much as I should. I can’t wait for this cold weather to go away so I can get back to running and training.

    • Nicola

      They are easy to forget about doing, especially if you are trying other harder speed sessions.

      Let’s hope you are back training soon!

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