Fartlek for Beginners: What It Is and 3 Sessions
What fartlek is and how to start: three sessions with exact minutes, how to gauge effort without paces and how to fit them into your week.
In this article
Fartlek is a way of training in which you alternate faster running segments with easy segments, without a rigid structure. If you are starting out, a simple session is this one: 25 minutes in total, with 6 hard segments of 30 seconds and 2 easy minutes between each one.
This article explains what it is, where the word comes from, how to gauge what "hard" and "easy" mean without needing paces, three sessions with exact minutes and how to adapt it to the race you are preparing for. It is intended for people who already run regularly and want to add some variety.
What fartlek is
The word comes from Swedish: "fart" means speed and "lek" means play, so it translates as "speed play". According to the usual account, it was developed in the late 1930s by the Swedish Olympic athlete Gösta Holmér.
It is considered a mix between continuous training and interval training. It alternates periods of faster and slower running, with a less strict structure than traditional intervals: the change of pace is decided by feel, by time or by landmarks on the route.
Fartlek versus intervals
| Feature | Fartlek | Intervals |
|---|---|---|
| Structure | Flexible | Fixed |
| How segments are marked | By time, landmarks or feel | By distance and pace |
| When it fits | To start adding variations | To work on specific paces |
How to gauge "hard" and "easy" without paces
One of the most common doubts with fartlek is what counts as fast and as slow. A simple reference is perceived effort out of 10:
- Easy: 3 to 4 out of 10. You can say full sentences without stopping to breathe.
- Hard: 7 out of 10. You can only say single words, but you are still in control of your pace.
Hard does not mean sprint. If the last segment is much slower than the first, you probably overdid it. It is a general reference, not an exact measure.
For more detail on what an easy pace means, see what pace to run your easy runs at. The full 0 to 10 scale is in perceived effort in running.
Three sessions to start
Each one includes a warm-up and a cool-down at an easy pace.
Session 1: introductory fartlek (25 minutes)
- 5 minutes easy.
- 6 repetitions of 30 seconds hard and 2 minutes easy.
- 5 minutes easy.
The math: 6 x (30 seconds + 2 minutes) is 15 minutes, plus 5 + 5 for the warm-up and cool-down, 25 in total. Of those, 3 minutes are at a hard effort.
Session 2: pyramid (35 minutes)
- 10 minutes easy.
- 1 minute hard, 2 easy, 2 hard, 2 easy, 3 hard, 2 easy, 2 hard, 2 easy and 1 hard.
- 8 minutes easy.
The math: 1 + 2 + 3 + 2 + 1 is 9 hard minutes and 4 recoveries of 2 minutes make 8. With 10 + 9 + 8 + 8, that comes to 35 minutes.
Session 3: fartlek by landmarks (40 minutes)
- 10 minutes easy.
- 20 minutes of play: pick a visible landmark, such as a lamppost, a corner or a tree. Speed up to it at a hard effort and recover until the next one.
- 10 minutes easy.
The math: 10 + 20 + 10 is 40 minutes. At the beginning, make the hard segments shorter than the easy ones.
| Session | Total duration | Time at hard effort | Structure |
|---|---|---|---|
| 1 | 25 min | 3 min | 6 x (30 s hard + 2 min easy) |
| 2 | 35 min | 9 min | 1, 2, 3, 2 and 1 min hard, with 2 min easy between them |
| 3 | 40 min | By feel | 20 min of segments between landmarks |
How to fit fartlek into your week
One fartlek session a week is enough to start. It replaces one of your runs and leaves the rest easy. An example with three running days:
- Wednesday: fartlek, session 2 (35 minutes).
- Friday: 40-minute easy run.
- Sunday: 50-minute easy long run.
The week adds up to 35 + 40 + 50 = 125 minutes. Do not do fartlek two days in a row or put it right before your longest run. To decide how many days to run, see how many days a week to run.
If you cannot yet run 30 minutes without stopping, start first with the plan in run 30 minutes without stopping.
A sample month
Here is how you could order the three sessions over four weeks, always one per week:
- Week 1: session 1 (3 hard minutes).
- Week 2: you repeat session 1 and notice you do it with more ease.
- Week 3: session 2 (9 hard minutes).
- Week 4: session 3, or you repeat session 2 if you need a bit more time.
Going from session 1 to session 2 triples the time at hard effort (from 3 to 9 minutes), so it is a notable jump. That is why it is recommended not to skip the repetition in the second week if you find it demanding.
If you cannot tell the efforts apart
At the beginning it is normal for "hard" and "easy" to feel similar. To get organized:
- Use the talk test: in the easy segments you can say full sentences; in the hard ones, only single words.
- If in doubt, go a bit easier in the hard segment. It is better to undershoot than to overdo it.
- Go by the time on your watch and not by pace: you do not need to know how many minutes per kilometer you are running.
- If you do not recover in the easy segment, lengthen the recovery in the next session.
Where to do it
A park or a path with few crossings makes the play of changes easier. On the street, choose a route where you will not have to stop at traffic lights. On a treadmill you can also do sessions 1 and 2, because they are marked by time, although session 3 loses its point without landmarks in the surroundings.
How to change fartlek for the race you are preparing
There is no single formula, but there is a general idea: the longer the race, the longer and more controlled the hard segments tend to be.
- For a 5K: shorter, livelier hard segments, with easy recoveries.
- For a 10K: segments of medium length, at a demanding but sustainable effort.
- For a half marathon: longer segments at a moderate-to-high effort, without reaching your limit.
It is a general guideline among coaches. If you are preparing your first 10K, the 10K training plan for beginners (in Spanish) already includes short strides and quality sessions that you can follow as they are.
Common mistakes
- Going all out in every hard segment.
- Shortening the recoveries until you do not catch your breath.
- Doing fartlek on consecutive days.
- Starting without a warm-up.
- Comparing it with intervals and obsessing over the exact pace of each segment.
- Changing the number of segments and their length at the same time.
When you have a recent race time
If later on you want to put paces on your segments, you can work them out in training zones. With a race time, the pace calculator and time predictor helps you check your paces.