By Owen PalmerThe fartlek training method was developed by Swedish coach Gösta Holmér in the 1930s, and the name is a Swedish word meaning “speed play.” Holmér designed it as a loose, unstructured way for runners to mix fast and slow running across varied terrain. Today it remains one of the most popular ways to build speed without the rigid rules of a track session.
Who Actually Created Fartlek?
Gösta Holmér was a Swedish track and field coach who worked with runners in Sweden during the 1930s. He is generally credited with formalizing fartlek as a training approach, and it spread quickly through European and then American distance running. Coaches of that era were searching for ways to develop both aerobic endurance and anaerobic speed in athletes who did not always have access to a track, so Holmér’s idea of running with changes in pace over natural terrain struck a chord.
Shopping for one? See our guide: 5k Training Plan Nike Review: Is It Worth It? (2026).
It is worth noting that fast-and-slow running existed in some form before Holmér put a name to it. Runners have long varied their pace during cross-country and hill training. What Holmér contributed was the framework, the vocabulary, and a method that coaches could describe and teach to others.
What “Fartlek” Means and Why the Name Matters
The Swedish word fartlek translates roughly to “speed play.” The name reflects the philosophy behind the method: it is meant to feel playful and intuitive rather than clinical. Instead of hitting a set pace for a set number of repeats, you change your effort based on how you feel, the terrain, and landmarks around you.
That looseness is the key difference between fartlek and interval training. A track workout might call for six 800-meter repeats at a specific pace with a fixed rest. A fartlek session might say “surge hard to the next light pole, then ease off until you feel recovered,” with no precise timing at all.
Why Fartlek Caught On
Several factors explain why the method spread so quickly after its introduction:
- It needs no equipment. A stopwatch is optional, and a park, trail, or quiet road is enough.
- It builds both systems. Faster surges train your ability to tolerate lactate and improve running economy, while the easier segments support aerobic development.
- It reduces monotony. Athletes who find steady running dull often stick with fartlek because each session changes.
- It adapts to any fitness level. Beginners can keep surges short and gentle, while advanced runners can push harder and longer.
How the Fartlek Method Works in Practice
Holmér’s original concept was flexible, but modern coaches usually apply a few basic principles. The surges are typically run at a hard but controlled effort, often somewhere between 80 and 95 percent of maximum effort depending on the runner’s goals. Recovery segments are jogged or walked until breathing settles. The total session length commonly falls between 30 and 60 minutes, including a warm-up and cool-down.
A sample structure for an intermediate runner might look like this: a 10-minute easy jog, then eight to twelve rounds of 1 minute hard followed by 2 minutes easy, then a 10-minute cool-down. Because the rhythm is self-directed, many runners use landmarks like trees, mailboxes, or hills to decide when to go hard.
Fartlek Tips for Getting the Most From the Session
- Start with a 10-minute easy warm-up before any surges.
- Choose surge targets you can see, such as a telephone pole 200 meters ahead.
- Keep the hard efforts hard enough to matter, but controlled enough to finish the set with good form.
- Use the recovery segments properly; jogging should feel genuinely easy.
- Track your total time and effort rather than obsessing over exact splits.
- Build gradually. Add one or two surges per week rather than jumping to a full set immediately.
If you are new to structured speed work, it can help to build a foundation first. Our guide to Training Plan for a 5K: A Step-by-Step Guide for Beginners explains how easy running and speed sessions fit together across a training block.
Fartlek Compared With Other Speed Sessions
Fartlek sits between steady running and more formal interval workouts. The table below shows how it differs from common alternatives.
| Session type | Structure | Main benefit |
|---|---|---|
| Fartlek | Unstructured surges and recoveries | Flexibility and mental freshness |
| Track intervals | Fixed distance and pace repeats | Precise pace control |
| Tempo run | Sustained comfortably hard effort | Lactate threshold development |
| Hill repeats | Repeated uphill efforts | Strength and form under load |
Many runners rotate between these sessions across the week. If you want a structured plan that includes speed work, see Intermediate 5k Training Plan: 8 Weeks to a Faster 5K. For a more formal interval approach, Running 5K Training Plan Intermediate: A 6-Week Speed Build (2026) shows how repeats progress over time.
What We’d Use
Fartlek needs very little gear, but a few items make sessions easier to run well:
- A basic GPS running watch, so you can review your surge and recovery times afterward. View on Amazon
- Cones or markers, which help set visible surge targets on an open field. View on Amazon
If you train with a watch regularly, our overview of Best GPS Watches for Interval Training covers what features matter most for speed work.
Related Questions
Is fartlek the same as interval training?
No. Interval training uses fixed distances, times, and rest periods, while fartlek lets the runner choose when and how hard to surge. Both build speed, but fartlek is more flexible.
How often should I do fartlek runs?
Most runners do one fartlek session per week during a build phase, separated from hard workouts by at least one easy day. Adjust based on recovery and overall training load.
Is fartlek good for beginners?
Yes, provided the surges are short and manageable. Beginners often do well with 30-second to 1-minute efforts and generous recovery. A doctor or coach should be consulted before starting any new training program if you have health concerns.
Can fartlek help with a 5K race?
It can. Fartlek develops the ability to change pace, which is useful during the surges and kicks common in 5K racing. Pair it with steady runs and a race-specific plan for best results.
Related reading
- Running 5K Training Plan for Beginners: 8-Week Step-by-Step Guide
- Run a 5K Training Plan: A 6-Week Guide for Beginners
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About Owen Palmer
Owen Palmer is part of our editorial team and reviews and edits our speed & interval running guides, checking product details against manufacturer specifications and owner feedback.
