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What is Fartlek Training and How Can it Help You Run Faster?

The term fartlek comes from the Swedish word fart (speed) and lek (play). Developed by Swedish track and field athlete Gösta Holmé in 1930, fartlek running involves varying your pace throughout your run with segments of faster running interspersed with easier paced running. It’s an extremely effective type of speed and endurance training for mid- to long-distance runs. Unlike traditional interval training, which uses timed or distance-measured segments, the work-rest intervals of fartleks are intended to be fun and unstructured (or can be lightly structured, depending on your goals and preferences).

How does it work?

In fartlek training, there’s more room for playing with pace and endurance; segments can vary by time, pace, effort, playful milestones (every dog you spot, maybe?) or heart rate. Most workouts typically target one or two paces and can be done on all types of terrain – roads, trails, hills. Another key difference? Unlike intervals, fartleks are continuous running sessions with active recovery periods rather than rest.

Fartlek runs challenge your body to adapt to various speeds by putting a little extra stress on your system. This stress leads to improvements in your lactate threshold and aerobic capacity, which conditions you to become faster. It is great for a variety of fitness levels and can be customised according to personal preference and current training situation.

Technically, your overall average heart rate should be higher for a fartlek workout than for intervals, due to the jogging recovery segments. However, the aim of fartlek training is to experiment with speed in a less structured way, so monitoring your heart rate and time should be secondary. Because fartleks encourage you to run without relying on data from a watch or treadmill, they can help you understand your effort or intensity level by giving you space to tune into you to how your body feels during a run – and adapting accordingly. You may find your natural self-pacing – a skill that comes in handy for long-distance events like half- or full marathons – improves with fartlek training.

What are the benefits?

  • The continuous change between effort and recovery increases endurance by forcing your body to push harder for longer periods of time.

  • Improves speed by improving when working at intensities close to your lactate threshold.

  • Helps to prevent injuries by strengthening tendons and muscles with variations in pace and running surface.

  • Great for both high intensity sessions and can improve your ability to add surges into runs, a useful skill for races.

  • Improves aerobic capacity through variation and additional stimulus – great for easing back into your running routine post-injury, tapering for a race, or just looking to get moving and keep things light.

  • Running – especially downhill – on different surfaces improves balance, coordination, and flexibility.

  • Allows you to learn about your own limits in a playful way and to stay motivated by providing distractions from discomfort.

  • Gives you a mental break from data-driven workouts; the latter of which can bring a new motivational element and psychological benefits to your training plan.

How do I incorporate fartleks into my workouts?

Classic style fartleks are based on inspiration and how your body feels, which makes them an easy interval-style workout to do on your own. You can vary your pace by the tempo of your playlist, physical landmarks or simply on a whim.

Fartlek training can be lightly structured, but think more ‘run faster to that tree, or the next intersection’ rather than ‘run X minutes at a faster pace, followed by Y at a slower pace’. Monitoring your heart rate? Try to not get totally caught up in the numbers – that goes for pace and time too. Your intervals should be sporadic and spontaneous, not set in stone.

To incorporate fartlek workouts, start by introducing some short periods of faster pace running into your normal runs, trying to maintain that pace for whatever goal you set for yourself (until the end of the song, or that bird-covered bench up ahead). The intervals can vary throughout the workout.

When you complete a fast segment, slow your pace to a recovery jog that’s just below your standard running pace until your breath returns to normal. Then kick back up to your normal running pace for a bit, switch it up with a speed surge, return to a recovery jog, lather, rinse, repeat.

Fun is a pivotal component of fartlek training. Don’t fancy doing it alone? Grab a friend or tune into Onetrack’s live virtual sessions.

View the Onetrack live virtual schedule here

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