Fartlek Training vs. Interval Training: Which One Is Right for You?

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When it comes to improving your running performance, incorporating some form of speed work into your training is essential. Two popular methods for boosting speed, endurance, and overall fitness are Fartlek training and interval training.

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Although both methods involve alternating periods of high intensity with recovery, they differ in structure, flexibility, and execution. In this comprehensive guide, we’ll compare Fartlek training and interval training, explore the benefits of each, and help you determine which approach is best suited to your needs and goals.

Fartlek training, a Swedish term meaning “speed play,” involves alternating between periods of higher intensity and recovery during a continuous run. Its spontaneity and flexibility set Fartlek training apart from traditional interval workouts. Speed bursts and recovery intervals are determined by how you feel and the terrain you’re running on.


Key Takeaway

Fartlek TrainingInterval Training
DefinitionCombines periods of faster running with periods of slower running or active recovery.Involves structured periods of high-intensity exercise followed by a fixed recovery time.
StructureLess structured, varying intensity based on perceived effort or specific landmarks.Highly structured, with specific work-to-rest ratios and predetermined paces.
FlexibilityOffers more flexibility to adjust workout intensity based on how you feel that day.Requires sticking to predetermined paces and rest intervals, less adaptable on-the-fly.
Mental EngagementCan be more engaging and fun, as it allows for spontaneous changes in pace and effort.Can feel more repetitive due to the strict adherence to set intervals and paces.
Performance MonitoringCan be more difficult to track performance and progress due to its less structured nature.Allows for easier performance tracking and progress measurement with set paces and intervals.
VersatilityEasily adaptable to any fitness level and can be performed in various environments.May require access to a track or specific equipment to accurately perform intervals.
Suitable ForRunners seeking variety, adaptability, and a more intuitive workout experience.Runners looking for a structured, data-driven approach to improving speed and fitness.
BenefitsImproved speed, endurance, mental toughness, and faster recovery.Increased aerobic and anaerobic capacity, improved speed, and enhanced overall fitness.
Choosing the Right WorkoutConsider your goals, fitness level, personal preferences, and available resources to determine whether Fartlek training, interval training, or a combination of both will best serve your needs.

Read Also: Advanced Fartlek Training Routines: Unlock Your Running Potential

Understanding Interval Training:

Interval training is a structured form of speed work involving alternating between high-intensity running and recovery intervals.

The duration, intensity, and recovery periods are typically predetermined, and the workout is often performed on a track or using a timer. Interval training can range from short, high-intensity sprints to longer tempo runs with brief recovery periods.

Key Differences Between Fartlek Training and Interval Training:


Fartlek training is less structured and more spontaneous compared to interval training, which follows a predetermined format.


Fartlek training allows for more flexibility in terms of intensity, duration, and terrain, while interval training adheres to a specific plan.


Fartlek training can be performed on various terrains and routes, whereas interval training is often done on a track or using a timer.

Fartlek TrainingFartlek Training is a form of continuous training that incorporates varied intensity levels throughout the workout, allowing for improvements in both aerobic and anaerobic capacities, which can benefit runners of all levels.Reaburn, P., & Dascombe, B. (2008). Endurance performance in masters athletes. European Review of Aging and Physical Activity, 5(1), 31-42.  
Interval TrainingInterval Training involves alternating periods of high-intensity exercise with periods of low-intensity recovery or rest, which can lead to improved cardiovascular fitness, increased running economy, and better overall performance.Billat, V. L. (2001). Interval training for performance: a scientific and empirical practice. Sports Medicine, 31(1), 13-31.  
Benefits ComparisonFartlek Training can be more engaging, allowing athletes to adjust intensity based on their fitness level or how they feel on a particular day. Conversely, interval training is more structured and can lead to more significant improvements in aerobic capacity and running economy.Laursen, P. B., & Jenkins, D. G. (2002). The scientific basis for high-intensity interval training: optimising training programmes and maximising performance in highly trained endurance athletes. Sports Medicine, 32(1), 53-73. 

Please note that these references are related to Fartlek Training and Interval Training and their benefits in general, rather than specifically focusing on comparing Fartlek Training vs. Interval Training to determine which one is right for an individual.

Benefits of Fartlek Training:

Fun and engaging:

The spontaneous nature of Fartlek training keeps workouts fresh and enjoyable.

Improved mental strength:

Fartlek training teaches you to listen to your body and adapt your workout accordingly, improving mental toughness.


Fartlek training can be easily tailored to individual goals and preferences, making it suitable for runners of all levels.

Enhanced aerobic and anaerobic capacity:

The combination of continuous running and speed bursts in Fartlek training improves both aerobic and anaerobic fitness.

Benefits of Interval Training:


The structured nature of interval training allows for precise control over intensity, duration, and recovery periods.

Measurable progress:

The predetermined format of interval workouts makes it easy to track and measure progress over time.


Interval training can lead to significant improvements in running performance and fitness in a relatively short amount of time.

Increased calorie burn:

High-intensity interval training (HIIT) has been shown to burn more calories than steady-state exercise, making it an effective option for weight loss.

Choosing the Right Approach for Your Goals:

When deciding between Fartlek training and interval training, consider your personal goals, preferences, and current fitness level:

  • If you prefer a less structured, more flexible approach to speed work, Fartlek training may be a better fit.
  • Interval training may be better if you’re focused on measurable progress and precise control over your workouts.
  • Beginners may benefit from the spontaneity and flexibility of Fartlek training , as it allows them to ease into speed work at their own pace.
  • More experienced runners may find interval training helpful for targeting specific performance goals and measuring progress over time.

Combining Fartlek Training and Interval Training:

For optimal results, you may consider incorporating both Fartlek training and interval training into your running routine:

  • Include Fartlek sessions for variety and enjoyment, particularly during base-building or early-season training.
  • During focused training periods, use interval training to target specific goals, such as improving your 5k or 10k race times.
  • Schedule a mix of Fartlek and interval workouts throughout your training plan, ensuring adequate recovery between high-intensity sessions.

Frequently Asked Questions

Which is better: interval or fartlek?

Whether interval or fartlek training is better depends on an individual’s goals, preferences, and fitness level.

Both methods can improve aerobic and anaerobic capacity but differ in structure. Interval training follows a structured pattern of high-intensity work followed by rest or active recovery, while fartlek training is more flexible and involves varying intensity levels based on how the athlete feels.

Some people may prefer the structure of interval training, while others may enjoy the freedom and variety of fartlek training. The best approach is to incorporate both types of workouts into a well-rounded training plan.

Why would you choose fartlek training?

You might choose fartlek training because it offers variety and flexibility, making it enjoyable and less monotonous than other forms of training.

It allows you to tailor the intensity and duration of each interval based on how you feel, which can be helpful for those recovering from injury or dealing with fatigue. Fartlek training also improves speed, endurance, and mental toughness, making it a valuable addition to any training program.

Who is fartlek training suitable for?

Fartlek training is suitable for a wide range of athletes, from beginners to advanced runners. Because it’s highly adaptable, it can be easily modified to accommodate individual fitness levels and goals.

It’s particularly beneficial for endurance athletes, such as runners and cyclists, as well as team sport athletes, like soccer or basketball players, who need to develop both speed and endurance.

Who is interval training suitable for?

Interval training is suitable for a wide range of individuals, including beginners, intermediate, and advanced athletes. It can benefit endurance athletes, team sport athletes, and even those looking to improve their general fitness. Interval training helps improve aerobic and anaerobic capacity, speed, and endurance. However, adjusting the intensity and duration of the intervals is essential to match your current fitness level and goals.

Is fartlek training the same as interval training?

Fartlek training is a type of interval training, but it differs in structure and flexibility. While both methods involve alternating periods of high and low intensity, interval training follows a more structured pattern with specific work and rest periods, whereas fartlek training allows for greater flexibility and spontaneity based on how the athlete feels during the workout.

Why do athletes prefer fartlek training more than continuous training?

Athletes may prefer fartlek training over continuous training because it offers variety, helps break monotony, and can be more enjoyable. Fartlek training also allows athletes to work on different aspects of their fitness, such as speed, endurance, and mental toughness, while continuous training typically focuses on maintaining a steady pace for a prolonged period.

Fartlek vs. tempo vs. interval

  • Fartlek training: Unstructured intervals involving varying intensity levels based on the athlete’s feelings.
  • Tempo training: Sustained effort at a challenging but manageable pace, usually performed at or slightly below lactate threshold.
  • Interval training: Structured high-intensity intervals followed by rest or active recovery periods.

Fartlek vs. interval

Fartlek training is less structured than interval training, with intensity levels based on the athlete’s feelings during the workout. Interval training follows a specific pattern with predetermined work and rest periods.

Difference between fartlek and continuous training

Fartlek training involves alternating between high and low intensity periods, while continuous training maintains a steady pace throughout the workout. Fartlek training helps improve speed, endurance, and mental toughness, while continuous training focuses primarily on aerobic endurance.

Interval training running

Interval training for running involves alternating high-intensity running intervals with rest or active recovery periods. This type of training helps improve speed, aerobic and anaerobic capacity, and running economy.

Tempo vs. interval run

Tempo runs involve maintaining a challenging but manageable pace for a prolonged period, usually around 20-40 minutes. The goal is to run at or slightly below your lactate threshold, which helps improve endurance and running economy. In contrast, interval runs consist of short, high-intensity intervals followed by rest or active recovery periods. Interval runs focus on improving speed, aerobic and anaerobic capacity, and overall running performance.

Fartlek vs. HIIT

Fartlek and high-intensity interval training (HIIT) involve high and low intensity periods, but they differ in structure and focus. Fartlek training is more flexible and athlete-driven, with intensity levels based on how the athlete feels during the workout.

HIIT is more structured and often involves specific work-to-rest ratios, such as 30 seconds of maximum effort followed by 30 seconds of rest. HIIT workouts typically target a broader range of muscle groups and can include various exercises, while fartlek training is primarily used for running or other endurance sports.

Benefits of fartlek training

Some key benefits of fartlek training include:

Improved aerobic and anaerobic capacity:

Fartlek training helps develop both the body’s ability to transport and utilize oxygen (aerobic) and perform high-intensity work without sufficient oxygen (anaerobic).

Enhanced running economy:

Fartlek training can improve the efficiency of energy expenditure during running, helping you run faster with less effort.

Increased speed and acceleration:

The varying intensity levels in fartlek training help develop the ability to change pace quickly.

Greater endurance and stamina:

Fartlek training helps build the ability to maintain a steady pace over long distances.

Mental toughness development:

Fartlek training challenges athletes to cope with discomfort and fatigue during high-intensity workouts.

Personalized and flexible training:

Fartlek training can be easily adapted to individual needs and preferences, allowing for a more enjoyable and effective workout.



Fartlek and interval training effectively improve running performance, endurance, and overall fitness. 

By understanding the key differences between the two approaches and considering your personal goals and preferences, you can choose the right type of speed work for your needs. 

Incorporate Fartlek and interval workouts into your training plan for a well-rounded and engaging running routine. Happy running!


John Smith is a passionate and experienced gym instructor, dedicated to empowering individuals to become the best versions of themselves through fitness. With over 10 years of professional experience, John has become a trusted authority in the health and wellness industry. Having worked with clients of all ages and fitness levels, John has developed a unique approach that combines a deep understanding of human anatomy and physiology with personalized fitness programs tailored to each client's goals and abilities. John's friendly and motivating demeanor enables him to build strong relationships with clients, guiding them on their journey to optimal health and wellness.

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