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What Is A Fartlek Workout?

Whether your goal is to beat your fastest mile, build endurance or turn that love/hate relationship with running into full-on love, incorporating fartlek workouts can help. If you're new to running — farleks are basically Sweden's gift to running, as fartlek means "speed play" in Swedish. Consisting of a blend of distance and interval training, fartlek training utilizes speed variations to help you build stamina and endurance.

At its core, it's a fun way to shake up your running routine. But before you hit the ground running, there are a few things you'll want to know. So, grab a pen, because you're going to want to jot these answers from the pros down.

Vital note: This article has been made available for informational and educational purposes only. It is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or another qualified health provider with any questions you may have regarding a medical condition. Your licensed healthcare professional can best provide you with the diagnosis and treatment of any medical condition and assist you as well in deciding whether a dietary supplement will be a helpful addition to your regimen.

What is fartlek training good for?

The list of fartlek training benefits is about a mile long. For starters, the freestyle speed variations of fartlek runs are good for shaking up workout intensity and helping you break through plateaus, explains David Donaldson, a personal trainer and Founder of Prestige Fitness.

"It works by getting the body out of its usual formalized training cycles by providing new challenges on the different energy systems," Donaldson tells Lively

Unlike interval or tempo runs (which are very structured) the opposite nature of fartlek training makes it perfect for those who are looking for a change in their routine.

Does fartlek training improve speed?

Since speed is literally in the name, you can expect to unleash your inner Usain Bolt. "Fartleks are a great way to help you improve your speed and endurance by helping your body adapt to different speeds," says Meghan Kennihan, NASM-certified personal trainer and RRCA/USATF-certified run coach.

You don't even have to be an experienced runner to give it a try. "Fartlek training is good for everyone: beginners, other sport athletes and advanced runners," adds Nancy Feinstein, a personal trainer and mindset coach/run coach.

Lastly, there is a mind-body connection with fartlek training that you won't quite find with other structured forms of running. "If you are having a stressful week or have a race coming up you can make it lower intensity by making it more playful and listening to your body on your sprints and recoveries," says Kennihan.

How long should a fartlek run be?

The beauty of fartlek running is in its versatility: "It's not bound by any time or distance rules," explainsJonathan Roussel,certified personal trainer and Founder of "Every runner can choose to randomly pick up the pace or slow down at any time during their runs."

Adding to that mind-body connection, this gives runners more freedom and a lot less guilt about slowing down when needed. In the end, it falls back on the golden rule of exercise: listening to your body.

If you did want a bit of structure, though, Stephens recommends 20 minutes for beginners. She adds that this duration can differ depending on the amount of higher intensity intervals that are included in the run: "The shorter those bursts, the easier it will be to have a longer workout. But for an intense one, 20 minutes is probably a good ball point figure to aim toward."

More advanced runners could aim for 20 minutes as well or even push themselves all the way up to 60 minutes, says Siobhan Milner,exercise scientist and Strength & Conditioning Coach at Siobhan Milner: Athletic Performance and Rehabilitation.

Just remember to always add a warm up before you hit the ground running. You can also add Vital Performance™ PRE to your pre-workout prep for a boost of muscle power and endurance.**

fartlek workout

How you complete your fartlek training lies within you: You decide what your run entails. You're not restricted to a specific location, either, as fartlek training can be taken pretty much anywhere: on the road, the treadmill, trails or even on hills.

Here's a sample workout:

  • 1-minute run (8/10 effort)
  • 1-minute run (6/10 effort)
  • 30-second sprint (10/10 effort)
  • 45-second run (8/10 effort)
  • 20-second sprint (10/10 effort)

"This would be an example of part of a shorter workout perhaps even shorter than 20 minutes, as the intervals are short and there is not a lot of recovery time involved," explains Leighanne Stephens, a personal trainer and online fitness coach. "The length really depends on the fitness of the individual."

The word "play" in the Swedish definition counts for something: You can play around with different structures to find one you like best. Donaldson recommends trying these on for size: 

Hill Fartleks

This is when you're running along a trail or on the road. "You can choose to increase your speed up an oncoming hill then followed by a slower down-hill recovery jog and the more sporadic you can make this terrain-play," Donaldson says, adding that the challenge can be looping around undulating plains or valleys with multiple hills. 

Impromptu Race Pace Fartleks

This can be performed on the fly during long-distance run days where they weren't planned. "You may suddenly decide to drop into your half marathon pace or even a faster 10K race pace for the next two miles," Donaldson says. "These interspersed segments will allow you to focus purely on effort level and make for a more immediate and demanding challenge offering a good heart rate spike."

Music Fartleks

This is probably the most fun of the three. Basically, you use music to guide the pace of your run: "When the song goes to a steady tempo slow your pace down and when the chorus kicks in add in a sprint for the duration," Donaldson explains.

What are the disadvantages of fartlek training?

As with any fitness program, there are pros and cons. When it comes to what are the disadvantages of fartlek training, injury is at the top of the list. "If you haven't run in a while, improper form can cause injury," explains Donaldson. "Adding a faster-style workout into your first few weeks could defeat any potential benefits."

While fartlek training is safe for beginners, it's recommended to incorporate a walk into the low-effort sections to "condition the muscles while increasing strength and building an aerobic base."

The next con with this style of running is the potential loss of motivation. "The disadvantages of fartleks are that you don't really get the metrics of running a 400 or a mile on the track," explains Kennihan. "Knowing the exact pace you were running and the time it took this means you can slack off on your goal pace or your workout."

Finally, this is not the type of exercise that can easily be done with a running partner. If your speed intervals are completely different, you may be left shouting your thoughts on Emily in Paris instead of getting to say them side by side. 

How many times a week should you do fartlek training?

With the risk of injury in mind, the answer to "how many times a week should you do fartlek training?" is only once. In some cases, Feinstein even recommends only once every two weeks, depending on your fitness level and training goals.

"It really depends on how often you run, and if you are training for something specific or not," she explains to Lively. Kennihan agrees, adding that fartlek training should be viewed as a supplement to your running training, rather than as the base. You can focus on structured runs instead, such as interval or tempo.

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