Fartlek training is a type of speed workout for runners. “Fartlek” is a Swedish term that translates to “speed play.”

Fartlek workouts are different than high-intensity interval training because they’re not structured by time. They’re flexible, so you can add various short bursts of speed to your runs.

Runners can have fun making up different fartlek workouts. That could include sprinting to a stop sign or tree you see in the distance. Or, you can give yourself challenges, like seeing how fast you can run up an upcoming hill.

Fartlek workouts can help improve your speed and endurance. They can also be a fun way to train!

Read on to learn more about fartlek workouts and how to add them to your routine.

During a fartlek workout, you’ll add short bursts of speed to your run. You’ll alternate between these speed bursts and jogging at a consistent pace.

The goal is to keep running throughout the entire workout. There’s no walking or stopping between intervals like you might find in other workouts. There’s more flexibility, though.

For example, you might sprint for different distances or times each interval, instead of sprinting for 30-second bursts the entire workout.

This continuous type of training can be beneficial for runners because it can help improve both your speed and endurance.

One 2015 study amongst athlete runners aged 18 to 30 found that 6 weeks of fartlek training helped improve their:

  • endurance
  • lactate tolerance
  • stride frequency
  • power
  • muscle elasticity

Studies also show that you’re more likely to stick with workouts you enjoy.

Since fartlek workouts can be a fun way to switch up your usual running routine, you may find you’re running and exercising more consistently than you normally would.

During a fartlek workout, you’ll add short bursts of speed to your runs. Then you’ll run at a comfortable pace until your next burst of speed.

Here are a couple sample fartlek workouts you can try.

Run to landmarks (individual fartlek)

  • Start with 5–10 minutes jogging or running at a relaxed pace to warm up. You should be able to hold a conversation comfortably.
  • Pick up the pace by sprinting toward a landmark in the distance such as a stop sign or building you see ahead. Aim for 20–60 seconds of speed, but each burst doesn’t have to be specifically timed.
  • You can also give yourself challenges, such as sprinting up or down that hill you see ahead.
  • After your speed burst, slow back to a jog for another few minutes until you’ve recovered your breath.
  • Repeat for around 20 minutes of alternating speed bursts and running. You can go longer if you’re a more experienced runner training for a longer distance.
  • Cool down with 5 minutes of easy jogging.

Follow the leader (group fartlek)

  • Start with 5–10 minutes jogging or running at a relaxed pace to warm up. You should be able to hold a conversation comfortably.
  • One runner takes the lead, speeding up, while the others run in a single-file line behind them.
  • The lead runner can keep up this speed for as long as they wish, but it shouldn’t be longer than a few minutes.
  • The lead runner slows back down to a jog or comfortable speed for a few minutes.
  • The runner in the back of the line runs to the front and takes over as the speed leader.
  • Runners continue to switch off with this pattern of speed bursts and jogging for 20–30 minutes.
  • Cool down with 5–10 minutes of easy jogging.

Fartlek is designed to be flexible and unstructured. All levels of runners can participate in a fartlek workout.

For beginners

For beginning runners looking to get started with some speed training, fartlek is a good option.

  • Pick up the pace. You don’t have to run at a full-on sprint during the speed intervals. Instead, just aim to pick up the pace for a short distance.
  • But still be able to talk. You should still be able to hold a conversation.
  • Pick a landmark in the distance. Look for a tree or mailbox ahead of you and run faster to that.
  • Use music to set your timing. You can try to pair your fartlek workout with music you’re listening to. Aim to pick up the pace during the chorus part of a song, for example. This is a good option if you’re running on a treadmill with headphones.
  • Warm up and cool down. Always remember to warm up in the beginning and cool down with a stretch after you run.

For more experienced runners

For more seasoned runners, fartlek can still be a great way to improve your speed.

  • Aim for 80 percent speed. Try to run at least 80 percent of your racing pace during the speed portion.
  • Use distance or use time. As you get more comfortable on fartlek runs, you can play around with increasing either the distance or length of time you’re running at full speed.
  • Pair up and take turns. You can also train with a buddy or group and take turns pushing the pace for one another.

Fartlek is different from other types of speed training like tempo running and interval workouts.

Tempo workout

These are designed for runners looking to improve a specific race time or pace.

After a warm-up, you’ll run at race pace (slightly above a comfortable talking pace) for a certain amount of time.

For example, if your goal is to run a 7-minute mile pace in a 5K race, you’d run close to that pace for a few minutes at a time, then slow back to a jog or walk.

Over time, you increase the amount of time or distance you’re able to hold your goal pace for.

Interval workout

During an interval workout, runners aim to run at an intense effort (80–90 percent effort) for a set amount of time, followed by walking, jogging, or stopping to catch your breath.

For example, running at speed for 2 minutes, followed by 2 minutes recovery. You’d repeat this for a certain number of times or for 20 minutes total, for example.

How does fartlek compare?

So which type of speed training is best?

Studies show that fartlek training tested well when compared to interval or timed tempo runs, especially for improving coordination.

One 2014 study compared fartlek training to other types of training like continuous running and interval training with a group of intercollegiate male soccer players.

The athletes who participated in fartlek training for 12 weeks tested better in speed and coordination than the continuous runners and those who didn’t train. The fartlek group also tested similarly to the interval training group.

While it’s difficult to say which type of training is “best,” try having a variety of workouts on your weekly calendar. That can make you a well-rounded runner and improve your overall physical fitness. Plus, the variety can keep you motivated.

If you’re a runner looking to improve your speed and endurance while also just having fun, try a fartlek workout.

If you always find yourself looking at your watch during runs, you might find you enjoy the unstructured plan more than you think.

Always warm up before starting your workout and cool down and stretch out after. Drink plenty of water on hot days and remember to have fun!