What Are Fartlek Workouts? Benefits, Drawbacks, & Routines

Fartlek might sound funny, but anyone who has ever performed one of these workouts knows it's no joke.

A Swedish word that means speed play, fartlek training, in its simplest definition, refers to an unstructured running workout. It combines your normal running pace with random intervals of a faster running pace of different speeds and distances.

It's used as an alternative to more structured forms of interval training to provide enjoyability while providing a unique stimulus. Intrigued? Keep reading, as we're about to explain it all!

Table of Contents:

• What Is Fartlek Training?
• How Do You Do Fartlek Workouts?
• Fartlek Training vs Interval Training: Key Differences
• 2 Types of Fartlek Workouts
• Advantages and Disadvantages of Fartlek Training
• Fartlek Training Workouts

What Is Fartlek Training?

To the general population, running seems like a pretty basic sport. In one sense it is, as it's a fundamental mode of locomotion for humans. However, to increase your running pace or improve your overall cardio, you need a better plan than "just run more."

Optimal running ability depends on a host of variables including VO2 max, lactate threshold, utilization of fuel, and increased tidal volume. To improve on these different variables, a runner must train in various intensities with different structures.

This partly explains the existence of various training workouts such as:

• Long Steady-State: Continuous running or longer distances at a consistent, steady pace
• Interval Training: Structured form of running consisting of brief distances of faster speeds followed by a recovery period. Work to rest ratio can be anywhere from 1:1 to 5:1. The work period does not need to be maximal.
• HIIT: A form of interval training that focuses on short bursts of exercise using maximum speeds.
• Lactate Threshold: A form of training where a runner runs as far as they can just below their lactate threshold.

Fartlek training is just another method of training to add to this list, which runners use to improve their performance. It's an unstructured form of interval training that mixes different speeds and distances, allowing a runner to run at different paces within one workout.

How Do You Do Fartlek Workouts?

While Fartlek workouts may be a foreign word (literally) to the general public, they are well-known in the endurance community. Fartlek is simply the Swedish term for "speed play."

In the 1930s, an elite Swedish runner by the name of Gösta Holmér was getting tired of being beaten by the superior Finnish team led by Paavo Nurmi. Having no access to any sort of special equipment, Gosta Holmer designed a new form of interval training to challenge his body.

In its original form, Gosta Holmer designed his sessions to build a better runner for racing. This was done by performing a long, continuous run that's interspersed with varying intervals of faster speeds or maximum speeds. Take this 5K run for example:

Distance (meters)	Intensity	Description
1,000	75%	Moderate intensity
300	Max speed	Sprint at maximum speed
500	70%	Moderate speed
400	Varied	50 meters at 90% intensity
		50 meters at 70% intensity
1,000	Varied	Quick surge (5 meters) every 100 meters
300	Easy	Easy running
800	Max speed	Run at maximum race pace
300	Easy	Easy running
400	Max speed	Sprint to finish

This is just an example but you can see how the running plan plays with different speeds.

Fartlek Training vs Interval Training: Key Differences

Some non-runners may be looking at the above fartlek workout and think that it looks like other forms of interval training. Some similarities but there are also some key differences.

1) Fartlek Workouts Consist Of One Continuous Run:

This is the primary difference between fartlek training and other forms of interval training. Remember that originally, fartleks were created to mimic racing. The one thing you don't do in racing is slow down drastically, let alone walk.

While you may have moments of easy jogging, you will never run slower than your half-marathon or marathon pace. Your "recovery time" does not consist of actual workout recovery. It's merely slower running.

Compare this to an interval training plan that requires you to slow down considerably during the recovery period. This is because the recovery period is supposed to allow you to recover so you can run at maximal speeds.

2) The Intervals Are Unstructured:

When performing interval training, the work and recovery intervals are set and you must follow them. Further, they are performed at a consistent duration and intensity.

This is not the case for fartlek runs. The intervals can vary widely in duration and intensity. For example, the recovery period could just be your normal running pace or it could be slower. In addition, the intensity of your recovery periods can vary as throughout the race.

For example, in a single fartlek session, your recovery period could include intensities equal to:

• Normal pace
• Normal long-run pace
• Slightly slower running than your work pace i.e. 95% --> 90%

In reality, the use of "work" and "recovery" is probably not even the most accurate. A better description could be intervals of differing specific paces.

3) Aimed At Endurance Runners:

First, everybody can benefit from any type of interval training plan. Further, no one group holds a monopoly on any one form of training. That said, fartlek training is generally seen more in the endurance world.

This is mainly because of the actual intent of this style of training which is to increase the endurance capabilities needed in endurance racing, mainly being able to recover while moving and utilization of lactate (details below!)

Sprinters are almost entirely interested in their anaerobic capabilities while endurance athletes benefit greatly from improving their aerobic system. To be clear, both these systems are important to both styles of running. The difference is which one is more important.

2 Types Of Fartlek Workouts

While Fartlek training allows variability in its running workouts, the degree to which this takes place can differ. There are two styles, unstructured and structured fartlek training.

1) Structured Fartlek Workouts:

During structured fartlek workouts sessions, the variability of the intervals would be written out before the run. While this still includes a mixture of endurance & speed work, you can think of it as organized chaos.

2) Unstructured Fartlek Workouts:

Unstructured fartlek workouts consist of hitting the streets or trails with no plan and running how you feel. You might be running and see a big tree so you decide to sprint there. You then slow down for a while, but your hype song comes on. You pick up the pace until you feel too much fatigue and dial it down. This continues.

Benefits Of Fartlek Training

Fartlek workouts are awesome and have grown to be a favorite style of training for professional and recreational runners of all levels. Here are are top benefits of fartlek training.

1) More Enjoyable:

Perhaps the most common benefit that draws people to Fartlek workouts is that many runners find them more enjoyable. This is especially true for those who loathe the idea of a structured running workout.

However, this shouldn't be confused with being easy, by the runner or onlookers. Fartlek training should be just as intense as regular interval training. However, the enjoyable side comes from a runner being able to choose what they're doing.

Some people can push themselves harder when left to their senses.

2) Can Seem Easier:

This is not necessarily true for everybody but depending on the person, Fartlek workouts can at times feel easier than a traditional workout, even if the overall intensity is the same.

When you go to perform a traditional 10k running session, you know your running pace is going to be similar for the entire 10k. Now your goal is to make it 10k.

On the contrary, if you were to go run a 10k fartlek session, it's going to be divided up into mini-stages. Being broken up like this can not only seem easier psychologically, but a fartlek run offers speed work, which can keep things interesting.

3) Customizable:

Due to the freedom of fartlek workouts, anyone can use them to fit their needs and goals. An athlete can vary the amount and intensity of the intervals while also mixing in various obstacles such as running up hills or steps.

As a result, an effective running workout could be made for any type of runner including trail runners, marathoners, and short to mid-distance runners.

Even sprinters can utilize fartlek training as an alternative to low-intensity steady-state cardio. While these workouts are almost always seen in running, fartlek training can be used in an array of endurance sports.

4) Allows For Auto-Regulation:

In some instances, fartlek running can be used as a form of auto-regulation. This idea is practiced by some weightlifters who will vary their workouts based on how they feel that day.

Since fartlek sessions allow the runner to control what they do (to an extent), a runner may want to change things up during the run. If they're feeling awesome, they may want to run at a faster pace for as long as they can. On the flip side, if they're feeling sluggish, they may want to want to dial it down and increase the amount of slower running they do.

5) Improved VO2max:

VO2 max is an athlete's ability to utilize the oxygen they take in. A higher VO2 max means an athlete can utilize oxygen more efficiently meaning more work.

While many people might point to HIIT as the best mode to improve VO2 max, any form of aerobic training can improve VO2 max.

6) Improves Utilization of Lactate (Lactic Acid):

We have spoken about this above so now we'll dive a little deeper. A large misunderstanding exists with lactate which is that it burns and is a bad thing.

In reality, lactate is a necessary compound required for energy. Increasing the ability to utilize it, in addition to increasing your lactate threshold, are variables that directly impact muscular endurance and are shown to occur in experienced runners¹.

Fartlek training can improve the body's ability to utilize lactate more efficiently and prevent the need to slow down. While no quality studies specifically look at this, anecdotally, many runners claim that this does seem to take place.

Drawbacks Of Fartlek Training

Fartlek workouts can be extremely effective when used appropriately. However, they do have some drawbacks. Here are some of the things you need to be cautious about.

1) Harder To Track Workouts:

Due to the variability in fartlek training, it's nearly impossible to track your training if you're using structured fartlek training. However, the unstructured nature is why so many people like fartlek training.

Therefore, fartleks should only be a part of your traditional training plan. If you're a serious runner, they should be used at the beginning of your plan to build volume before your training gets specific.

In addition, don't use fartlek training for your short runs or recovery runs. Their best place is in place of your long run.

2) Requires Personal Accountability:

Anytime a person is left to their own to push themselves, mental strength will determine who is successful. Fartlek training is not a recovery run or a "fun run". While it can be more "fun", it's still serious training.

If you do fartlek training, be prepared to push yourself. At the same time, don't fall into the trap of pushing yourself too hard.

Refrain from favoring the specific type of training and use it for its intended purpose. Go out and have fun but remember that the goal is to improve your running!

How To Use A Fartlek Workout In Your Training Plan

Want to add fartlek training into their overall program? Here are some guidelines to think about when you design a program.

1) Fartlek Running To Improve Endurance:

When training for endurance, fartlek training is a great option to replace or add a long run into your training plan. You can make this a part of your weekly run, every other week, or whenever you want something different.

Here are some suggestions for endurance-based fartlek training.

• Use 5 minutes to warm up as well as 5 minutes running a cool-down pace at the end.
• Entire work sessions should be 45 minutes or longer.
• Use a higher ratio of intervals that are longer distances at a sub-maximal pace (80-90%).
• Use intervals of maximal speed work short (10-20 seconds), as if you're passing another runner.
• Mix in intervals of tempo runs (the maximum steady pace at a certain distance).

2) Fartlek Running In Strength Training Or Speed Work:

If you're a sprinter or even a strength athlete trying to improve your muscular strength, fartlek training still has a role. While some suggest fartlek training needs to be 45 minutes, there's no reason you can't use the principles and apply them to shorter distances.

• Use 5 minutes to warm up as well as 5 minutes running a cool-down pace at the end.
• The entire work session can be 25-45 minutes.
• Use a higher ratio of hard efforts (90%-Max) and short-distances.
• In some sessions, rarely run at the same pace. Change the pace more frequently.

Fartlek Training Workouts

As mentioned above, fartleks' personalized nature can make writing a general program challenging. However, here are some fartlek training examples to get you started.

When you see a percentage, you don't need to for it to be exact. Further, these can differ based on your fitness level. Holding 90% for 30 min is easy for some yet impossible for others. If it's too hard, to the point where you can't do it, it means you need to use a slower pace. Think about these numbers as a percent of your maximum pace for that distance. If your fastest 500m pace is 12km/hr and it has 90%, use a 10.8km/h pace.

When you see "max", this means run at the maximum speed you can at that given time and still be able to continue.

Endurance 10K (Session A):

Distance (meters)	Intensity	Description
1,000	70%	Moderate intensity
1,000	85%	High intensity
500	70%	Moderate intensity
1,000	90%	High intensity
500	70%	Moderate intensity
2,000	90%	High intensity
500	70%	Moderate intensity
500	75%	Increased intensity
500	80%	Increased intensity
500	85%	High intensity
500	90%-95%	Sprint or near maximum intensity
1,500	Max Steady	Maximum steady state (consistent pace)

Endurance 10K (Session B):

Distance (meters)	Intensity	Description
2000	85%	Moderate intensity
500	Max Steady	Maintain a consistent pace
2,000	80-85%	Moderate to high intensity
100	100%	Maximum sprint
3,000	80%	Moderate intensity with short maximum surges
		10-15 seconds maximum surge every 500 meters (6 total)
2,000	Lactate	Lactate threshold pace (challenging but sustainable)
400	Sprint	Sprint to finish

Track Workout:

Lap	Intensity	Description
Lap 1	75%	Moderate intensity
Lap 2	Max Steady	Maintain a consistent, challenging pace (steady state)
Lap 3	75%	Moderate intensity
Lap 4	Varied	Run up and down bleachers or stairs
Lap 5	75%	Moderate intensity
Lap 6	Max Steady	Maintain a consistent, challenging pace (steady state)
Lap 7	75%	Moderate intensity
Lap 8	Varied	Run up and down bleachers or stairs

Speed Workout 5K:

Distance (meters)	Intensity	Description
500	70%	Moderate intensity
500	Intervals	10m (max speed) / 90m (70-75% intensity)
500	75%	Moderate intensity
500	Intervals	30m (max speed) / 70m (70-75% intensity)
500	75%	Moderate intensity
500	Intervals	50m (max speed) / 50m (70-75% intensity)
500	75%	Moderate intensity
1,500	Intervals	100m (max speed) / 400m (70-75% intensity)

“Push” It (Any Distance):

Segment	Description
Warm-up	Easy-paced running to prepare your body
Above Threshold	Increase your pace just above your threshold
Fatigue Building	Continue above the threshold until fatigue builds
Recovery	Slow down to 70% of your maximum effort
Repeat	Repeat the cycle as needed for your workout

The Rundown On A Fartlek Workout

Fartlek runs are a novel training plan that can accommodate the needs of any fitness level. It prepares your body's ability to succeed in racing or general athletic performance with its unique physical demands. Mental strength is built as a requirement to push yourself.

To top it off, you have the freedom to structure your fartlek run as you want. You can just put your shoes on, head out the door, and see what happens. Regardless of your goal, reaching it will be more effective, efficient, and enjoyable by adding fartlek runs to your training!

Interested in more running content? Check out the Best Strength Training For Runners!

References:

1. ‌Costill DL. Metabolic responses during distance running. Journal of Applied Physiology. 1970;28(3):251-255. doi:10.1152/jappl.1970.28.3.251