Fartlek Training for Runners

Speed Play to Improve Your Pace and Endurance

Man running on a track

Verywell / Ryan Kelly

Fartlek is a Swedish term that means "speed play." Fartlek training is a form of interval or speed training that can be effective in improving your running speed and endurance. Fartlek running involves varying your pace throughout your run, alternating between fast segments and slow jogs.

Fartlek Training Benefits

While traditional interval training uses specific timed or measured segments, fartleks are more unstructured. Work-rest intervals are based on how the body feels. With fartlek training, you can experiment with pace and endurance as you run, which helps you tune in to your body and how it is performing.

Many runners, especially beginners, enjoy fartlek training because it involves speed work, but it is more flexible and less demanding than traditional interval training. Another benefit of fartlek training is that it doesn't have to be done on a track and can be done on all-terrain, such as roads, trails, or hills. Plus, you won't need a stopwatch to time your intervals.

Fartlek training puts a little extra stress on your system, eventually leading to faster speeds and improving your anaerobic threshold. Improving your anaerobic threshold can boost your body's ability to train longer at higher intensities.

This happens due to increases in your VO2 max, which is a measure of how much oxygen you can take in and use. A better VO2 Max generally leads to increased performance.

Disadvantages of fartlek training include a higher risk of injury and strain, especially for beginners who are more prone to shin splints. Fartlek training is also demanding, so you shouldn't do it every day.

How to Do Fartlek Workouts

To do a fartlek workout, try introducing some brief periods of slightly higher pace into your regular runs. Maintain the faster pace for a short distance or time interval, such as 200 meters or 30 seconds. The intervals can vary throughout your workout, and you can use landmarks such as streetlights or telephone poles to mark your segments (rather than measuring out those 200 meters).

Once you complete a fast segment, slow your pace to below your normal running pace until you fully recover and your breathing has returned to normal. Then return to running at your normal pace, and incorporate more slightly fast intervals later in the run.

Fartlek runs should be fairly short since they are more intense. The actual higher pace portion of the run should last about 30 seconds. You can gradually add more time to this faster-paced portion as you improve, up to 60 seconds.

Fartlek Training Example

Here's an example of a 40- to 45-minute fartlek workout suitable for beginners.

  • 10-minute warm-up at an easy pace
  • 1 minute on (fast pace), 2 minutes off (easy), 2 minutes on, 1 minute off
  • Repeat the fartlek set 3 to 4 times
  • 10-minute cool-down at an easy pace

Fartlek Training on a Treadmill

When you don't want to enjoy your speed play outside, you can do a treadmill fartlek workout. If you watch television during your treadmill time, you might use commercials as a time to go into a speed interval. At the gym, you can make a game of it and do your sprint when a new person gets onto or off of a machine near you.

Another option is to speed up during the chorus of songs on your playlist or when certain songs play. This can help relieve treadmill boredom.

One precaution is that you'll need to use the buttons on your treadmill to increase and decrease the pace. Since this can slow you down and disrupt your form, you may prefer to use longer durations for each phase, so you have less contact with the control panel.

A Word From Verywell

Fartlek training is an excellent way to add some variety, fun, and interest to your running training. This type of speed work can also boost your performance, increase your cardiovascular output, and allow you to run at higher intensities for longer periods.

Keep in mind that beginners should go slow when introducing fartlek training into their workouts. It is more intense and can lead to a greater risk of injuries and strains, such as shin splints. Get help from a running coach if you are unsure how to add fartlek training to your routine.

4 Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Christine Luff, ACE-CPT
Christine Many Luff is a personal trainer, fitness nutrition specialist, and Road Runners Club of America Certified Coach.