Fartlek Training: Benefits, Risks & Uses Guide

Advantage of fartlek training

Fartlek training offers a highly versatile and unique form of training designed to train your body to become faster over longer distances.

Fartleks can be performed by people of all fitness levels and backgrounds, pretty much anywhere with a decent amount of space. For experienced runners, many turn to a fartlek run as a new challenge that breaks up their normal routine. These sessions offer a challenging workout that push runners outside their comfort zone and combines a mix of warm-up pace, speed work, sprinting and cool downs into a constant interval training session designed to increase your heart rate - but more about that in a moment.

In this guide, we aim to answer all your queries and curiosities surrounding the world of fartlek training. Here you will find the following contents:

Before we get stuck in, for any keen runners actively searching for thier next challenge, download our FREE prospectus for information on OriGym’s extensive range of health and fitness qualifications. Or, if you're someone looking to inspire the lives of other by kickstarting your career in fitness, head staright over to OriGym's Personal Training Diploma where you can gain both your L2 and L3 at a discounted price. 

What is Fartlek Training?

Advantage of fartlek training

Fartlek training (translated from Swedish meaning ‘speed play’) is a type of running that is very similar to interval training. It is a method of speed training that is highly effective in improving both endurance and running speed. 

Fartlek running involves varying your pace while you run, alternating between slow jogs and fast, high-intensity segments throughout the entirety of its duration. 

One of the best things about fartlek is that your intervals don’t have to be rigid and set in stone. Part of the fun of this type of training is its spontaneity. You can jog, run slowly, walk, or burst into a sprint if and when you want. It’s entirely up to you and how your body feels, if you think you can push yourself a little further, you're encouraged to do so; at the same time, if you’re struggling, you can slow down the pace and you don't have to feel guilty for it as it is part of the format. 

There is no restrictions on where or when you can do fartlek training, all we will say is if you do plan on doing your sessions in the evening, read our running at night guide which offers a full guide of how to stay safe and get the most out of your workout.

How you measure your intervals is completely down to you. Most popularly, many opt to use lampposts as measures, sprinting between two or three then jogging for the next couple. Other notable measures include: jogging to music, with the song itself acting as an indicator on when to pick up or slow down the pace (for instance: sprinting when you hit the chorus and slowing down during choruses), some choose to speed up or slow down using moving objects as measures (i.e. cars or dogs).

The unpredictability and inconsistency of fartlek training is one of its primary attractions. 

How Does Fartlek Training Work?

fartlek training vs interval training

We’ve briefly touched on it, but fartlek training is unique as it offers a completely unpredictable style of exercising. The primary concept remains the same, however, how you perform it can change as much as you choose for it to. You can change the measures you use, the speeds that you go, the distance and route you take - all variables can be altered however and whenever you like.

The one element of consistency is its goal, and that is to play with speed in a natural way and improve both endurance and overall fitness. 

Later in the article we will provide examples of fartlek training structures and sessions, however to address it more holistically; during a fartlek session, you will typically run for either a set distance or time and within that time you perform at a high intensity and do not rest. 

While fartlek primarily focuses on speed work in its practise, it still offers benefits for flexibility and is generally less rigorous than more traditional interval training. Fartlek training also puts extra stress on the body system, resulting in faster speeds and improved anaerobic endurance and stamina - this refers to a person’s ability to sustain intense, short duration activity, such as sprinting or resistance training. 

Benefits of Fartlek Training

So, now we know what fartlek training is, you're likely wondering ‘what are the benefits of fartlek training?', how will introducing this type of training serve advantageos to you?  Allow us to explain.

#1 Promotes Weight Loss 

Benefits of fartlek training

Believe it or not, but the random and erratic nature of fartlek training can play a hugely important role when your goal is to lose weight.

How? Well, this can be explained through a couple of methods. Firstly, fartlek training activates both your aerobic and anaerobic metabolism. For context, aerobic metabolism is the way in which the body creates energy through the burning of carbohydrates, fats and amino acids in the presence of oxygen. This form of burning is used for the sustained production of energy for exercise and other body functions and is used in exercises such as: running, cycling and walking. 

On the other hand, anaerobic metabolism is the way the body creates energy through the burning of carbs in the absence of oxygen. This happens when the lungs cannot cannot provide the bloodstream with enough oxygen to sustain the demands of the muscles for energy.

Anaerobic metabolism is generally only used for short bursts of energy, such as HIIT or sprints or when you're lifting heavy weights. 

Compare this to interval training, which many people put fartlek up against, this method of speedplay works to activate just one metabolism. Though slow interval training can activate aerobic metabolism to an extent - it is nowhere near to the same level that fartlek does. Instead, intervals (particualrly fast intervals) more exclusively activate the anaerobic metabolism.

The reason fartlek targets both is due to its variation methods and the fact it ranges widely between intensities and speed.

In a sense, you’re tricking your metabolism into working harder in fartlek training than it would during interval training as it is having to adapt and activate both metabolisms - therefore burning even more calories; that is why fartlek training is one of the most effective ways of losing weight quickly. 

Additionally, the benefits fartlek training has for weight loss extend beyond the workout itself, as fartleks can increase our resting metabolic rate, which the the rate in which we burn calories when we're not doing exercise, instead sitting/sleeping/resting.

In addition to this, this method of interval training helps suppress post-exercise appetite and cravings by altering the levels of hormones that cause us to feel hungry (ghrelin).

 #2 Helps Build Strength and Endurance

Advantages and disadvantages of fartlek training

Another of fartlek’s benefits is that it will help you build not just your strength, but your endurance too. 

Fartlek training can be done anywhere at any pace, meaning it’s a great type of training for you to do if you’re looking to build muscle strength. 

Changing pace and the surface you’re running on regularly will work the muscles and tendons more. The more you work your muscles, the stronger they’ll get. Soon enough you’ll start to see noticeable differences in your leg muscles.

Plus, the stronger your muscles are, the less likely you are to suffer from random injuries you may pick up whilst you run. 

The benefits of fartlek training for muscular endurance can be demonstrated by the findings of a recent 2020 study, which analysed the effect of fartlek training on muscular endurance among cross country runners. The study was conclusive in its theory that fartlek does benefit muscular endurance, with all subjects showcasing improvements.

Another 2015 study, which also highlighted the fartlek advantages for endurance, stated in their findings:

“Fartlek training results in the calf muscles learning to pact more quickly and thereby generating work at a higher rate, they become more controlling. The calf muscles get this by recruiting more muscle fibers, around two or three times as many when evaluated to running on the flat.”

Another benefit of having stronger muscles is that you’ll be able to run for much longer too, meaning fartlek is a great training exercise for anyone looking to build their endurance. 

Another way you can energise your body is through a number of run-enhancing products. For instance, our shortlist of the best running gels to fuel your workouts offer a great aid for both long and short distance sessions taht you may find useful.

The more you practice interchanging between a gentle jog and an intense sprint, the better you’ll get, meaning you’ll be able to carry on for longer the more time goes on. 

Building your strength and endurance has to be one of the most rewarding of fartlek’s benefits for sure! 

#3 Burns More Calories 

Disadvantage of fartlek training

One benefit of fartlek is that by doing it regularly you’ll see yourself burn more calories than you would by doing interval training, for example. 

By varying the intensity of your workouts, you will burn more calories than you normally would if you were to keep a steady pace. 

Doing fartlek training means your workouts will become much more efficient because you will burn more calories during your workout without having to increase the time spent doing the workout. 

In fact, doing a 45-minute run using the fartlek training model, a 68kg runner could potentially see themselves burning well over 500 calories, from less than an hour of running. You can see why this has such a powerful effect on weight loss and fat burning!

What's more, the market of running products is bigger and better than ever; if you want a gadget that allows you to track your calories burned, as well as your distance ran and at what pace you're travelling at, there is a product for just that. If you need help selecting one, we have a full shortlist of the 13 best running watches on the market here.

Due to fartlek running being far more intense than regular running, and interval training for that matter, you’ll definitely burn a shed-load more calories than you normally would. 

As far as fartlek benefits go, this stands as a favourite for many people participating in fartlek training. 

#4 Improves Your Mindset and Mental Strength 

who would benefit from fartlek training

One of fartlek training’s psychological benefits is that it will help you change your mindset. Not only will it help get you in the zone ready for race-day, but will also leave you feeling better mentally too. 

Fartlek training is a huge help towards getting you into the race mindset. This sort of training mimics the surges you may put on in races, for example, to pass other runners, reach a checkpoint on time, or to make that final sprint for the line. 

Incorporating these surges of speed into your training can help you learn how much you can push your body over shorter segments whilst also keeping enough in the tank to go the whole distance and finish the race. 

Fartlek trains the mind just as much as it trains the body. Everyone’s experienced that feeling mid-run or race where they don’t feel as though they can go further, as though they’ve got nothing left to give. Fartlek training helps curb those feelings and thoughts. The more training you do with all the speed variations of fartlek, the more resistant you become to giving up mentally mid-race. 

Your body can go on for much longer and can go much faster than the mind will have you believe. Fartlek helps you see that. 

And that’s just the beginning! We haven’t even mentioned the whole host of endorphins that your brain will release when you’re doing your fartlek training, giving you that natural high and washing all your worries away whilst you run. 

An early study looked into the effects of fartlek training on self-esteem and found that through 16 weeks of commitment to the activity, undergraduate students benefited from improved self-esteem when compared to those who continued to follow their normal daily routine. Therefore supporting the theory that fartlek improves a person’s self-esteem. 

Improving your mindset is one of the most important benefits of fartlek training for runners, as it helps them push through the mental barrier that had been holding them back in the past. You can read more mental health benefits of running here.

#5 It’s Adaptable and Flexible 

Example of fartlek training

Flexibility and adaptability are undoubtedly some of the best benefits of fartlek training for sure! 

If you hate boring runs and training sessions, then you’re in luck, because no single fartlek training session ever has to be the same if you don’t want it to be! 

There is so much flexibility within the fartlek workout. For example, a low-intensity session is highly effective if you just want to start getting to grips with the workout style, if you’re tapering for a race, or if you’re easing back into running following an injury.

A high-intensity workout can also help you push yourself to the limit and smash through barriers that had previously been holding you back, as well as give you an idea of what your limits are. 

Fartlek training is a stress-free workout that can be really playful if you want it to be. The playfulness of the workout can revive your love of running, and is a great way to boost your motivation, as well as provide you with all the mental and physical benefits we’ve previously mentioned too! 

As well as this, its completely adaptable to your location and the seasonal periods and doesn't have to be as taxing as long distance runs in the winter months. Instead, you can make them short and simple or even do your fartlek sessions inside on a treadmill! Though, if you are out in the colder months, then make sure to equip yourself with the kit selected in our winter running gear list.

So, if you want to go on a gentle, low-intensity run that’s fun and playful, then fartlek is the type of training for you. Or, if you’d rather a high-intensity running session where you push yourself to the limit and test your mental and physical strength to the max, then guess what? Fartlek is the type of training for you too! 

#6 Improves Fast and Slow Twitch Muscle Responses 

fartlek training 1

Another of the many fartlek training benefits is its ability to help improve your fast-twitch muscle responses

From a physiological vantage point, one of fartlek training’s many benefits is that it allows for the training of fast and slow-twitch muscle responses. 

In short, there are two types of skeletal muscle fibres, one being slow-twitch, and the other being fast-twitch. 

Slow-twitch muscle fibres are used to support long-distance endurance activities such as marathon running, whilst fast-twitch muscle fibres are used to support quick, powerful movements such as weight-lifting and sprinting. 

Fast-twitch fibres can generate more force than slow-twitch muscle fibres but are much quicker to fatigue compared to slow-twitch fibres. 

When you’re doing fartlek training, you’re working both fast and slow-twitch muscles, because you’re both sprinting and running at a more leisurely pace at various points throughout your workout. 

The confusion of fartlek training, what with its flexible style and mixture of fast and slow running, trains your muscles to be adaptable and flexible to changing running conditions. Over time, your muscles will get stronger, so soon enough you’ll be able to switch up your pace with ease and not face as much resistance from your muscles as you did when you first started! 

One of fartlek training’s benefits is that it helps make your muscles more adaptable and ready for changes while you run. This can also help prevent you from suffering from as many running-induced injuries, which we’ll go into next! 

#7 Reduces Risk of Injuries 

fartlek training physiological benefits

Another of fartlek’s benefits is its ability to help you from suffering running-induced injuries, but you’ll only experience this benefit if you train properly. 

According to the American Council on Exercise, interval training, such as fartlek, could be vital in avoiding and preventing injuries that are usually caused by repeated aerobic exercises. This is because fartlek training gives your body the opportunity to gradually adapt to faster running, and progresses from there. 

Fartlek training allows you to experience the rewards of anaerobic exercise without straining your muscles. 

As you do more fartlek training, the stronger your muscles will become, and the likelihood of you suffering from muscle-related injuries from running will significantly reduce!

And, with how random and fun fartlek runs can be, preventing injuries doesn’t have to be boring either  - as your experience is as entertaining as you want it to be. There are little restrictions; though, if you are choosing to integrate a lot of hill runs in your workout, then you my want to check out our tips for running downhill to further reduce the risk of injury.

Additionally, it is important to note that if you’ve never partaken in fartlek training before, you should start out slow and steady, and build yourself up from there. If you don’t, you run the risk of straining or injuring yourself, which is the last thing you want or need! So, until your body is conditioned to fartlek, keep your workouts short and infrequent to begin with! 

#8 It’s for Everyone 

Advantages of fartlek training

Though fartlek is used by athletes from many different sports to help them improve their stamina and strength, that doesn’t mean that it’s exclusively for just them! One of the biggest benefits of fartlek training is that it’s for anyone and everyone, so long as they’re willing to run and work hard! 

Because there’s no set structure or goals to fartlek training, that means you can work out and train however you like. 

If you’re new to running and haven’t done it properly before, you can do a nice, low-intensity workout and learn about what your limits are and how much your body can take. For a headstart, there are a mass number of apps that can help get your feet up off the ground and work towards improving your stamina and technique. Take a look at OriGym's selection for the best running apps for beginners for that boost.

Or, if you’re a seasoned running pro and love nothing more than taking part in marathons or races, fartlek will benefit you just as much too, no matter if you’re preparing for your next race or marathon or not! 

If you want to work on overtaking the competitors, surging past the opposition, or sprinting for that finish line, fartlek training will give you the opportunity to do all those things and more. 

If you’re coming back from an injury, fartlek is also the training method for you. With fartlek, you decide when enough is enough. Only your judgement matters here. It’s your body after all, and no-one knows it better than you do. 

If you’re looking for a running workout that will benefit you, no matter what your experience or fitness level is like, then there aren’t many better options than fartlek training! 

#9 Can Be Done Solo or in a Group 

Fartlek training advantages

For many people, working out alone can be daunting, with a recent survey showing that over 16% of people don't work out because they don't feel confidence enough to.

One of the benefits of fartlek training is that it can be a communal workout session if you want it to be! 

Fartlek training is highly individualised, as one of the main benefits of this type of workout is that you decide how much is too much and how far is far enough. If you want to sprint to the next lamppost and jog until you see another red car, that’s entirely up to you, and that’s one of the reasons why it’s so freeing and refreshing from boring old HIIT. 

But another of these types of workouts benefits is how easily it can be adapted to suit a group setting. 

In a group, you can race and challenge each other to see who can go the fastest, who can go the furthest, and who can outlast who, and turn it into a fun mini-competition of sorts. It’s a great way to have fun and a laugh with your friends, whilst also keeping fit and pushing yourself to do better fitness-wise. 

As a group, you can also adjust the intensity and distance of your workout, depending on how other members feel on that particular day. You can work towards achieving a specific goal together and cheer each other on when things start to get tough. 

Fartlek’s flexibility of being both an effective solo and group workout is undoubtedly one of it’s biggest benefits for sure! 


If you're an avid runner, whether your preferred training be fartlek, marathon, triathlon or a routine evening jog, we think you will benefit from the following reads: 

Disadvantages of Fartlek Training

Just like with any form of exercise, fartlek comes with its risks, and unique ones at that. Below we have otlined 3 of the primary disadvantages some may encounter with fartlek training - however, these may not apply to everyone.

#1 Requires an Element of Creativity

Fartlek training for beginners

We said the disadvantages wold be unique; how often do you come across this one in reference to exercise?

Fartlek is executed according to feeling and, because of that, a dose of creativity is needed. While this is deemed as an advantage of fartlek training to some people, to others, this can in fact be a leading factor that prevents them trying it out. Fartleks require constant inspiration; each session comes down to you and sadly, inspiration is not always present.

This means there will be occasions where it is increasingly difficult to motivate yourself and instead you would rather follow a set training routine that lays out the distance and time on a plate for you. 

#2 Increases Risk of Injury For Beginners

Fartlek training examples

Perhaps the most notable risk of fartlek training; due to the erratic nature of fartlek training, it comes with its cons - one of which is increasing the potential for injury in beginners. 

The saying "don't run before you can walk" applies significantly here. If you haven't mastered the art of form, as well as generic running technique and aerobic base and you jump straight into very fast speed-work in your first sessions of fartlek, it increases the possibility of injury for beginners as they haven't trained and adjusted their body to this form of cardio and heavy impact. 

For a headstart, we have an entire article centered on tips to improve running technique for you to check out.

With this being said, it is okay to add in some moderate speed intervals, such as a a walk/jog combo – but avoid manic sprints initially if you haven’t run in years.

If you are completely new to running with no prior experience, then fartlek training is not ideal for you. Before you start putting speed into your training, you need to get into shape. Adding faster running segments during the first few weeks of training increases the risk of injury.

When you decide to start running, the most important thing is to first focus on the proper running technique and gradually increase fitness through continuous training. Only when you reach a certain fitness level, i.e. you are able to run for at least half an hour without stopping, you can start inserting faster segments into your training.

Side note: speedwork specifically does not cause injury, more common training errors associated with it. For instance, running too fast with poor biomechanics, running too fast too often, or simply too fast for your ability - all of which can quickly pomote an injury. 

#3 Increases the Difficulty of Partner/Team Training


While this disadvantage of fartlek training may only apply to some individuals and could in fact be deemed a benefit to others, it is still worth mentioning for the sake of the former.

This issue is at risk of presenting itself if you and the people you train with run at different paces and have different staminas and running experience. If you choose to stick together during random speed intervals, you're unlikely to be matching each others performance, therefore hindering each others workout as one person is either being worked beyond their ability, or not being challeneged enough.

For this reason, we would suggest if you are choosing to do fartlek sessions with somebody else, then you may want to consider someone with similar abilities and pace to your own to get the most out of your workout and to be working to a structure that allows you to progress.

If, however, you enjoy training as part of a group regardless of restrictions, then why not motivate others in the same way? Here at OriGym, we offer a group exercise instructor course that provides you with all the knowledge on how to become a successful group exercise and fitness instructor.

Fartlek Training Structure

Because fartlek training is so versatile and unstructured, you can construct workouts in nearly endless combinations, such as:

  • Fixed distance for the repetition
  • Fixed time for the repetition
  • Varying distance/time for the reps
  • Varying pace for both the rep and the recovery interval

Though fartlek sessions are typically done on the road or trail, they’re not as structured as interval training and workouts, so they can be done pretty much anywhere that has the space for you to run. To further explain the different styles of fartlek training, we have provided some examples below:

Time Based Fartlek


Perhaps the molst popular form of fartlek training, time based fartlek embodies what is typically considered the spirit of this speed-play. Each repetition is based on time, as oppoed to distance.

A few examples could include:

  • 10 x 30 seconds speed-run, 1 minute recovery (slowing down the pace to a jog)
  • 10 reps of 1 minute fast-paced and 1 minute slow
  • 6 reps of 5 minutes at tempo effort and 1 minute slow-paced
  • 2 miles of 2 minutes fast-paced and 1 minute slow-paced.

The options available to you within this type of fartlek workout are nearly endless.

Don't forget to kit yourself out with the best running gear to ensure you avoid injury and maximise your performance.

Random Fartlek

Fartlek training disadvantages

A random fartlek is when the repetitions or the recovery is varied based on a number of variables, such as: the song you're listening to, the terrain or the objects you pass.

A few examples may include:

  • Songs can be used in versatile ways, you can speed up depending on the tempo of a song, or you could alternate a playlist with short and long songs and use those to determine your workout.
  • Run uphills fast and then slowly downhill on rolling terrain
  • Train with a friend who can determine the repetition length for you.
  • Run fast towards certain landmarks (trees, lammposts, cars, etc) and recover until the next landmark
  • You could keep it simple by speeding up until you feel like slowing down, and slowing down until you feel like speeding up. Repeat.

Random fartleks are deemed best for those who's specific fitness isn’t the goal. They can be made easier than traditional workouts so they help transition the athlete between easy running and hard running.

Alternatively, if you're looking to improve your speed, you're encouraged to increase the speed of the slower section of your run gradually over time until they become closer to the speed of your faster segments. To improve your endurance with fartlek training, you can do this by reducing the slower, recovery segments. Or, if you want to improve both endurance and speed, then you can combine both aspects.

Bare in mind that the fun of fartlek training is it is all down to you; how you feel, what you want to do, how far you want to run and how fast and slow you want to go - meaning the options are near endless.

Fartlek Training Tips

Now we've explored the benefits of fartlek training and covered any potential risks it may present, you may be wondering whether there are an fartlek training tips that can amplify your success; or maybe you're already experienced with fartleks and you're looking for ways to enhance your performance. Below we have outlined some of the top tips for you to trial depending on your ability and previous experience with fartleks.


Fartlek Tips For Beginners

  • Pick a landmark in the distance - Use objects in the distance as indicators for when to speed-up and slow-down.
  • Pick up the pace - Remember you do not need to run at full-sprint, even during the speed intervals. Instead, with fartlek training you should still be able to hold a conversation.
  • Use music to set your timing - If you don't want to use ojects, try using your music as the indicator that determines when to increase and decrease your speed. I.e: speed up during the chorus part of a song. 
  • Warm up & cool down - While this applies to most/all workouts, you should always remember to warm up at the beginning and cool down with a stretch after you run.

Fartlek Tips For Experienced Runners

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

  • Aim for 80% of your speed - Aim to/work towards being able to run at least 80% of your racing pace during the speed segment.
  • Pair up and take turns - Rather than objects and music, instead why not pair up with a friend/group and take turns pushing the pace for one another.
  • Use distance or use time - As you get more confident with fartlek training, you can try increasing either the length of time or distance you’re running at full speed to challenge yourself.

How Often Should You Do Fartlek Training?

benefits of fartlek training for runners

There is no straight forward answer when it comes to the frequency of fartlek training; it all comes down to the programme, training regime you're following (if any) and your goals. 

Many running programmes will include methods of speed training just once or twice a week, as this has been proven to be effective is producing results and progress. 

One to two sessions may not sound like a lot, however fartlek training is taxing on the body and requires that you recover throughly after a session; any more than two sessions a week will not allow sufficient time for this. 

Additionally, fartlek training should be paired with a well-balanced plan in order to prevent the risk of injury and aid improvement. For this reason, we recommend pairing your fartleks with easy runs and rest days to achieve a good balance of activity, rest and variety.

For more information on the importance of rest days and how many you need, read here.

Why is Fartlek Training So Popular?

fartlek training benefits

It’s important as a runner to not always run at the same speed or distance, as the body will quickly adapt to this, getting comfortable with the session and therefore preventing progression as you will eventually plateau.

In order to improve speed and endurance, it is important to vary and expereiment with speed and be prepared to push  out of the comfort zone - the answer? Fartlek sessions.

If you want to improve your speed and endurance with alternative methods, then there are a number of cardio and aerobic exercises that offer this benefit also.

It is common knowledge in the running community that fartleks are the answer to seeing consistent progression. Not only do fartlek sessions have beneficial effects on the body's physical condition, but they also train the mind in becoming stronger, strengthening willpower and thus allowing the runner to keep running and not give up as easily. 

When we race, it is common amongst many, if not all, of us to encounter moments where our mind can overwhelm us and tell us to stop. The more training sessions we do that incorporate this speed variation, the stronger and more resistant we become to giving up mentally mid-race. The body can usually go much longer and faster than the mind would have it believe it can.

For these reasons, fartlek training has gained mass attention and popularity from those looking to progress their running and general athletic performance.

Who Benefits From Fartlek Training?

fartlek benefits

What athletes would benefit from fartlek training if it lacks structure and consistency, you ask? Well, you may be surprised to know that footballers, rugby players, hockey players, tennis players, and, of course, runners all benefit from this method of training. 

Footballers, for example, are constantly sprinting, slowing down, jogging, then bursting back into a sprint again as they race around the pitch with the ball, so fartlek training is one of the best kinds of running training that they can do. It’s the same with rugby, hockey, and tennis players too! 

Many people restrict the use of fartlek training solely to enhance running performance, however, fartlek training works with practically any maintained cardio, from swimming or cycling to running or rowing. Any cardio exercise which involves maintaining a level which can be changed at any point is ideal.

When swimming in a pool, you could randomly do a maximum effort lap every now and again. When rowing you could choose a point to go full steam ahead. Or when cycling you could find a point to pedal as fast as you can. The options are endless!

With all that being said, it is of course worth mentioning that fartlek training offers a number of benefits to runners and their performance. Similarly to interval training, fartlek sessions improves a number of factors that have a direct positive impact on running performance, these include: lactate threshold, ventilatory threshold and VO2Max - we will explain these further below.

Maybe this doesn't sound like the right fit for you; in that case, why not check out our guide on trial running and see if that suits your training style and preferences more. 

Fartlek Training vs Interval Training

fartlek training advantages and disadvantages

While fartlek sessions may sound similar to interval training, there are some distinct differences that mean one may be more beneficial than the other depending on your goals. Where fartlek training involves both increasing and decreasing running speed while on one continuous run, interval training follows a more structured pattern which typically consists of high intensity, to low intensity, then rest and repeat. 

With fartlek training, you may not have a specific goal in mind - in fact it's actually advised that you don't have a distinct goal as it allows runners to be more spontaneous with their session. Whereas to get the most out of your interval workouts, the general advice is to have a goal that you're working towards.

It is important to note, however, that both fartlek training and interval training are equally great and effective methods of speed-work and just because you are doing one does not mean that you cannot mix the two styles and do both styles in the same week. 

Alternatively, if you'd prefer a longer workout of a slower pace, you may benefit from reading our guide on long distance running.

Below we have outlined the main similarities and differences between fartlek and interval training so you can identify which one meets your prefernces and goals most.

Similarities Between Fartlek Training and Interval Training

  • Improve VO2max (our maximum rate of oxygen consumption) - This is beneficial as the higher the VO2max, the greater the ability to efficiently utilise oxygen to power the muscles and maintain performance levels.
  • Increase lactate threshold (the level at which lactate starts to enter the blood) - The buildup of lactic acid is what causes us to feel/experience muscle cramps when we run. Through both types of training, runners can increase the threshold at which lactate starts to build up, which can decrease cramps and therefore increasing performance.
  • Increase ventilatory threshold (the point where our breathing rate starts to increase, eventually to the point where breathing becomes challenging) - Through both types of running styles, you can work to delay the point at which you become breathless when you’re running at a moderate-high speed.

fartlek training benefits

Differences Between Fartlek Training and Interval Training

  • Fartleks simulate a real race more so than an interval run does, therefore better preparing you for for running events.
  • The fast-paced running segments of a fartlek session should be faster than your normal pace, but not an all-out effort.
  • Intervals consist solely of your maximum effort when running.
  • Fartleks should be one continuous run.
  • Intervals feature high-intensity periods, followed by short breaks 
  • Intervals are advised for those looking to improve and achieve quick take-offs and sudden bursts of speed. 
  • Fartlek workouts are considered best for people looking to work on their mid-run endurance and speed boosts.


In short, if you’re a runner, whether beginner or experienced, who is looking to improve both your speed and endurance in a fashion that allows you to have fun, try a fartlek session.

Is is particualrly recommended for those who get bored of the same routines or find they're forever clock-watching during their usual run. The lack of structure and plan provides a more spontaneous workout that you can be sure will never be boring, and if it is - change it!

Side note: ensure you always warm up before a fartlek workout and cool down afterwards - and most of all, enjoy it!

For more information on the range of courses that you can study with us here at OriGym, click here to download a free course prospectus


  1. Kumar, P.. “Effect of fartlek training for developing endurance ability among athletes.” International journal of physical education, sports and health 2 (2015): 291-293.
  2. Antony, Varghese & Tomar, Rakesh. (2016). Effect of Sixteen Weeks of Fartlek Training on Self- Esteem of Saudi University Students. Indian Journal of Science and Technology. 9. 10.17485/ijst/2015/v8i1/103369.
  3. Palanisamy, Dr. (2020). Effect Of Fartlek Training On Muscular Endurance Among Cross Country Runners. 22. 1750 - 1753.

Written by Annie Williams

Fitness Content Executive, OriGym

Join Annie on Facebook at the OriGym Facebook Group

Graduating from Liverpool John Moores University with a BA (Hons) in Journalism, Annie specialises in mental and physical wellbeing, with a specific interest in nutrition and mindfulness. Her long standing interest in fitness is what brought her to OriGym, and led her to become a qualified Personal Trainer and obtain specialist qualifications in Advanced Sports Nutrition. Annie’s primary professional attraction lies in following and tracking the ever-changing trends in the fitness industry. Beyond OriGym, Annie divides her time between personal writing, her passion for the countryside and mountain walking, and charitable runs.

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