Your Complete Guide To Interval Running + 6 Workouts For Runners

Intervals can unlock serious speed gains in your running.

As a certified personal trainer and running coach, I am often asked about high-intensity interval training (HIIT), as the benefits have been popularized in general fitness spheres for weight loss, boosting cardio fitness levels, and providing an efficient workout.

However, while HIIT gym workouts are in their more nascent stages in terms of popularity, distance runners have been doing interval running workouts for decades.

Much like any form of high-intensity interval training, interval running workouts involve bouts of running at a higher intensity, such as your race pace or VO2 max pace, and then taking a short recovery period before going hard again.

What I love about interval workouts for distance running is that there are tons of ways to vary interval training workouts.

Variations are based on fitness level, target race distance, and physiological adaptations such as improving VO2 max, increasing anaerobic threshold, or helping runners get more comfortable at race pace efforts.

In this guide, we will discuss what interval running workouts involve, the benefits of running intervals for distance runners, and the types of interval training workouts for runners so you can add them to your training program.

People running on a track.

What Is Interval Training Running?

Interval training is a training method that involves alternating between running at a faster speed for a specific distance or amount of time followed by recovery periods.

For example, an interval workout for a half marathon runner might involve 6 x 1,000m at 5K pace.

While interval workouts are now commonplace in training programs for middle-distance and long-distance runners, they have only been widespread in running plans since the 1950s, when runner Emil Zatopek implemented this revolutionary style of training.1Billat, L. V. (2001). Interval Training for Performance: A Scientific and Empirical Practice. Sports Medicine31(1), 13–31.

Emil Zatopek’s training style helped him break 18 world records and win five Olympic medals. Today, most running plans still rely on the concepts introduced by this middle-distance runner.

Is Interval Training the Same As HIIT?

High-intensity interval training, more commonly known as HIIT workouts, is a specific type of interval training that requires you to reach at least 85% of your age-predicted maximum heart rate during the hard intervals. 

Not all interval running workouts are necessarily high-intensity interval training, as half marathon and marathon runners can do longer anaerobic threshold workouts such as tempo runs that may be just below 85% of your maximum heart rate, depending on your fitness level. 

Advanced runners have a higher anaerobic threshold, so they are typically able to run at a higher intensity for these types of longer intervals.

Beginners, on the other hand, who have not yet developed their aerobic and anaerobic fitness levels to the same extent would be at a lower intensity for this particular type of interval running workout.

That said, most interval running workouts fall under the umbrella of HIIT workouts.

A person running on a track.

What Is the Benefit of Interval Running for Long-Distance Runners? 

Here are some of the top benefits of interval training for marathon training, half marathon training, 5K and 10K races, and even recreational running performance:

  • Interval running workouts add variety to your training plan, which can decrease the risk of injury because you are varying the stresses and loads placed on your muscles, bones, joints, and connective tissues.
  • High-intensity interval training burns calories, and can accelerate fat loss and weight loss for runners trying to lose weight.
  • Interval running workouts are efficient because you can facilitate physiological adaptations such as improving VO2 max or aerobic capacity,2Scribbans, T. D., Vecsey, S., Hankinson, P. B., Foster, W. S., & Gurd, B. J. (2016). The Effect of Training Intensity on VO2max in Young Healthy Adults: A Meta-Regression and Meta-Analysis. International Journal of Exercise Science9(2), 230–247. running economy, and cardiovascular fitness level3Bacon, A. P., Carter, R. E., Ogle, E. A., & Joyner, M. J. (2013). VO2max Trainability and High Intensity Interval Training in Humans: A Meta-Analysis. PLoS ONE8(9), e73182. in a short amount of time for each interval training session relative to a steady-state run.
  • The higher intensity efforts of interval workouts build mental toughness to help you push through discomfort on race day.
  • Interval workouts can improve your running economy.4Barnes, K. R., & Kilding, A. E. (2014). Strategies to Improve Running Economy. Sports Medicine45(1), 37–56.
  • Interval workouts are scalable for beginners through advanced runners by increasing the number of repetitions, doing longer intervals, running at faster paces, decreasing the period of time you take for rest between each interval for recovery, etc. As you get fitter through your training plan, you can build up the total volume of the higher intensity effort in an interval training session, decrease the amount of time devoted to the recovery period, take an active recovery by jogging instead of walking or standing still, and add more advanced types of interval running workouts to your overall interval training plan.
  • An interval training program can be used with any training approach to long-distance running such as heart rate training, training by rate of perceived effort (RPE), or training by pace.
A person running hills.

What Are the Best Interval Running Workouts?

There are many types of interval training workouts for distance running, each with unique benefits.

However, here are the primary types of interval workouts to include in your marathon training or half marathon training plan:

#1: Hill Workouts

Hill sprints are one of the most versatile interval running workouts because they combine strength training with speed training and can be useful for runners of all fitness levels and all target race distances.

Short steep hills help build all-out running speed and power and longer hills improve anaerobic and aerobic fitness.

Hill workouts can be scaled by increasing the number of reps and of course, increasing the speed or intensity level.

People running on an indoor track.

#2: VO2 Max Intervals 

These interval workouts involve running different distances on the track at your VO2 max pace in order to stimulate physiological adaptations that hopefully improve your VO2 max, running economy, and anaerobic capacity.

Improving aerobic capacity will help you have a more efficient cardiovascular system for long-distance races from the 5K though the marathon, which can help you use oxygen more efficiently at faster running speeds. 

An example is five repetitions (reps) of 1000m, which is 2.5 laps of the track, at 95% of VO2 max pace.

According to Jack Daniels, one of the most renowned distance running coaches, suggests that in the absence of knowing your true VO2 max, well-trained runners can use their 3K running pace or a running speed that you can hold for eight minutes as an indicator of your VO2 max running pace. 

Interval sessions for improving VO2 max should have intervals that take between three and six minutes for each of the reps.

#3: Shorter Intervals

It can also be helpful to do track intervals with shorter reps at mile pace or faster to train your anaerobic system.

A classic speed training workout for distance runners from the 5K to the half marathon or marathon is 10 to 12 reps of 400m at mile race pace or 5 to 10 seconds faster than 5K pace. 

Long-distance runners can also benefit from all-out sprints like strides at the end of an easy run.

A person running over a bridge.

#4: Fartlek Runs 

A fartlek run is a type of interval running workout that involves interspersing short periods running at a faster pace built into a continuous endurance run.5Kumar, P. (2015). Effect of fartlek training for developing endurance ability among athletes. ~ 291 ~ International Journal of Physical Education, Sports and Health2(2), 291–293.

For example, after a 10-minute warmup of easy running, you might throw in 10 repetitions of 90 seconds at 5K race pace followed by 60 seconds at your normal steady-state running pace.

Fartlek workouts are essentially like speed workouts on the track but may also be less structured. Some runners, for instance, may choose to use landmarks such as stop lights or lampposts to denote when to switch running speeds. 

#5: Tempo Runs and Lactate Threshold Intervals

Tempo runs or lactate threshold interval sessions on the roads are a great way to simulate race conditions with hilly courses.

The lactate threshold occurs around 83-88% of your VO2 max or roughly the pace you could hold at maximum effort for an hour of running. 

For most runners, the lactate threshold pace is about 15-20 seconds per mile (9-12 seconds per kilometer) slower than your 10K race pace.

Therefore, if you run a 45 minute 10K race, your tempo runs and threshold interval workouts should be run around 7:30-7:35 minutes per mile or about 4:39-4:42 minutes per kilometer.

Tempo runs are a minimum of 20 minutes at your lactate threshold pace, but you can also do shorter intervals with recovery periods as you build up your endurance.

A person stretching after a run.

Tips for Adding Interval Running to Your Training Plan

As with your overall mileage, it is important to gradually build up the intensity and number of reps or distance for your fartleks, hill workouts, track interval workouts, etc.

While there are many training, health, and running performance benefits of interval running, even short periods at an all-out effort, or running at a high RPE or heart rate is taxing on your cardiovascular, metabolic, and musculoskeletal system.

Therefore, it is very important to build in enough recovery after your interval training sessions. 

Consider cross-training or taking an active recovery workout the next day, especially when you are first starting interval running workouts or are doing longer and higher intensity interval training sessions.

You should always do a warm up and cool down to bookend the intervals, even if you are doing longer intervals like a tempo run or lactate threshold intervals that aren’t at an all-out effort. 

A person stretching her arms out in front of her.

The warm up increases blood flow to your muscle groups and prepares your body for running faster.

The cool down after hard workouts serves as a form of active recovery to help begin flushing the metabolic byproducts out of your muscles and bringing oxygen and nutrients for muscle recovery.

Overall, almost all long-distance runners should incorporate some type of interval training into their overall training plan. 

The benefits of interval workouts span the gamut from decreasing the risk of injury from constantly running the same steady-state pace every day to helping you get fitter, faster, and stronger in a shorter period of time due to the intensity and efficiency of interval running.

For an inside look at the different types of running workouts, check out this next guide:


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Amber Sayer is a Fitness, Nutrition, and Wellness Writer and Editor, as well as a NASM-Certified Nutrition Coach and UESCA-certified running, endurance nutrition, and triathlon coach. She holds two Masters Degrees—one in Exercise Science and one in Prosthetics and Orthotics. As a Certified Personal Trainer and running coach for 12 years, Amber enjoys staying active and helping others do so as well. In her free time, she likes running, cycling, cooking, and tackling any type of puzzle.

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