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Fartlek Training | A Complete Guide

Updated: Feb 3

A runner fartlek training.

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Fartlek is a form of training that involves short bursts of high-intensity exercise. Though typically used during running workouts, fartlek can be applied to an assortment of activities and training tasks. For example, fartlek is equally as effective for rowing, cycling, skipping, swimming, and even some resistance exercises. And, as you’ll soon see, it can even be incorporated into many sporting disciplines.

The aim of this article is to provide you with a comprehensive insight into fartlek training. First, we’ll begin with the basics – where it originated, what it is, and how it differs from other forms of interval training. After covering the key characteristics, we’ll assess some of the main benefits that are associated with fartlek – such as its capacity to improve speed and strength.

And finally, you’ll get access to a range of fartlek training resources. These include session plans, training tips, and methods of applying fartlek to different exercises and sports. When you walk away from this article, you’ll do so with all the tools you need to get the most out of the fartlek training method.

Fartlek training quick finder


What is fartlek training?

Fartlek ‘refers to a training method developed in Sweden that simply means ‘playing with speed’,’ (Triathlon). Sometimes translated to just ‘speed play,’ such sessions involve varying intensity levels throughout a workout.

The conventional fartlek plan consists of sprinting between lampposts. Concluding a couple of steady state miles, by which point the runner is thoroughly warmed up, they will begin to sprint sections of the route.

Depending on the exerciser’s fitness levels, the total fartlek distance could be as long or even exceed the preceding run.

But what if you run in the countryside (or on a treadmill) where there are no lampposts? How do you fartlek without that essential piece of urban equipment? Read on and all will be revealed.

Is fartlek HIIT training?

Yes . . . and no. As I wrote above, fartlek involves varying levels of training intensity. The variations or bursts of speed are grouped into intervals which are interspersed with low-intensity recovery periods. Starting to sound suspiciously like HIIT.

However, the difference – and it’s a minor one – that distinguishes fartlek from HIIT is that the former is not as formulaic. What does that even mean?

Your standard HIIT workout consists of the ‘systematic manipulation of exercise and relief intervals,’ (Exercise Physiology). The work/rest ratio is usually predetermined before the sessions. The durations are devised in such a way as to provide you with enough recovery time to fully maximise the high-intensity intervals. Of course, the exerciser’s fitness and training goals largely dictate the work/rest ratio.

Related: Supercharge your heart with this HIIT Running Workout >

Fartlek session example

In contrast, fartlek is far more free-form. Whereas HIIT is governed by a precision chronometer, fartlek uses its environment when playing with speed. The lampposts (trees, cars, or counts (one elephant . . . two elephants . . .)) are rarely spaced evenly apart. This means that some sprints are going to be longer than others.

In addition, because fartlek is often conducted outdoors, you have undulating terrains and the elements to contend with. It’s usually the case that, while battling a belligerent headwind, you hit a hilly section when your next set of sprints starts. But no mind. You must fartlek on regardless.

Example of fartlek training

Previously we reviewed a conventional fartlek session. To put that explanation into context, I’ve created a fartlek training plan that you can try. You’ll notice that there are three distinct sections – warm-up, fartlek, and cool-down – each with a specific duration. There’s a reason for this.

Typically, fartlek workouts are conducted over a series of distances. For example, a runner might warm up with a steady-paced two-miler followed by a mile or two of fartleking. Concluding the fartlek, they’ll cool down with a gentle jog over the final mile. (Distances are subject to change depending on the runner’s aerobic fitness.)

Of course, while those distances work well when applying fartlek to running, they will not if your workout consists of cycling, swimming, or skipping. Timings, by contrast, can be applied to any cardio exercise. Also, they are easier to adjust for variations in fitness levels.

Fartlek training plan.

Benefit of fartlek training

Because fartlek training is a variant of HIIT, it confers similar health and fitness benefits. Such benefits include increasing aerobic and anaerobic fitness (Physiology of Sport and Exercise). It’s also a great way of ‘increasing VO₂ max, lactic threshold, running economy, and fuel utilisation,’ (NSCA’s Essentials of Tactical Strength & Conditioning).

After a couple of weeks of intermixing fartlek bouts into your obligatory 5-mile run, you may well start to notice that not only is the distance getting easier but that it’s also taking you less time to complete.

Fartlek training for cardiovascular endurance

This is also a consequence of the many adaptations that taking place due to the increased demands fartlek exerts on the aerobic endurance system. These adaptations – stronger heart, greater stroke volume, enlarged arteries and veins – enhance the efficiency of the cardiopulmonary network. At its essence, this helps to deliver more oxygenated blood to the working muscles.

Another benefit of fartlek is that it can be used to ‘reduce the monotony of elongated training periods.’ Unlike HIIT, which is ruled by a ‘precise exercise-interval training prescription,’ fartlek can be applied on the fly.

Fartlek methods

The protocol is based more on “how you feel,” not what’s written on your plan. This, though you had no intention of fartleking during that 20-mile cycle, boredom got the better of you and you felt like shaking things up a bit.

In sum, fartlek is a form of HIIT that keeps ‘training fresh and fun while improving various components of cardiorespiratory as well as performance efficiency,’ (NSCA’s Essentials of Tactical Strength & Conditioning).

Related: Could your quads survive this HIIT Cycling Workout?

Fartlek training | From theory to practice

So far, we’ve reviewed the characteristics of fartlek training. In addition, we’ve contrasted it with HIIT and outlined features that distinguish the two exercise methods. For example, we now know that fartlek is a free-form variant of interval training.

And whereas HIIT is a ‘precise’ ‘training prescription’ that’s formulated before a workout, fartlek is ‘mood dependent.’ Yet just because fartlek is a bit more laidback, there’s no evidence to suggest that it is any less effective at promoting aerobic and anaerobic fitness.

Of course, the best way to master a training methodology is to integrate it into your routine. Using the following key takeaways as refresher, have a go at the 20 minute fartlek run workout plan. Once you've got a taste for fartlek training, begin developing the duration of your sessions.

Key takeaways

  • Fartlek is a free-form variation of HIIT (high-intensity interval training).

  • Unlike HIIT, fartlek is not dictated by a precise training prescription. You don’t draft up a plan or finely tune the work/rest ratios before fartleking. You use it when the fancy takes.

  • Another distinguishing feature of fartlek is that the bouts differ in length. A HIIT session may consist of, say, 40 x 20 sec intervals – each followed by a rest of equal duration. In contrast, when fartleking, you might apply the very scientific run-like-mad-until-I-gas training methodology.

  • Fartlek training can be used as a ‘fun’ way to liven up a dull steady state session.

  • Fartlek is far more flexible than it’s given credit for. It can be incorporated into a vast and diverse range of sports and exercise tasks.

  • So, stop reading and start playing with speed!

20 minute fartlek run

20 minute fartlek run training plan.


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Fartlek training blog concludes with the Hungry4Fitness Book of Workouts.


About Adam Priest –

A former Royal Marines Commando, Adam Priest is a content writer, college lecturer, and health and fitness coach. He is also a fitness author and contributor to other websites. Connect with Adam at

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