Although many runners find running on the treadmill to be monotonous, even those who embrace the benefits of treadmill workouts as a tool for training often find that they need some way to spice up a treadmill run to pass the time.
Structuring your treadmill running workouts with intervals not only accomplishes this mental “busyness“ need to prevent boredom, but it also challenges your cardiovascular, metabolic, and muscular systems for a more efficient and effective workout.
But, when planning your running workouts you may wonder, how many treadmill intervals should I do in a workout? How should I structure treadmill interval workouts?
In this guide, we will discuss ways to structure and measure treadmill interval running workouts based on your fitness level and training goals and ultimately answer your question, how many treadmill intervals should I do in my running workouts?
Let’s dive in!
What Is a Treadmill Interval Workout?
Before we look at how many treadmill intervals you should do to achieve your running goals, let’s discuss what treadmill interval training means.
Beginners might have heard the term “treadmill intervals“ or “interval treadmill running workouts“ but may not be entirely sure what that entails.
A treadmill interval workout refers to any walking, jogging, or running workout (or a combination thereof) that involves cycling between bouts of more vigorous running or walking with less intense recovery periods.
For example, a treadmill running interval workout might involve jogging for a warm-up and then running at a faster speed for two minutes, slowing down the speed for one minute of recovery, and then running fast again for two minutes.
You might complete this cycle five times and then cool down.
An incline treadmill walking workout might have a warm-up and then you would increase the incline of the treadmill to 6% grade for one minute.
After the incline walking interval, you would return the treadmill to a one percent or 0% grade for one minute.
You might continue this interval incline walking workout 15 times over your workout.
Treadmill workouts for beginners who are trying to start running—such as those doing a couch to 5k treadmill plan—would have treadmill intervals that have periods of running followed by walking breaks.
As fitness improves and you work your way through the couch to 5k training plan, you will have longer treadmill running intervals with shorter and fewer walking breaks until you can run continuously without the breaks.
There are countless ways to structure treadmill intervals, but the general takeaway is that instead of running, jogging, or walking at a steady state either in terms of pace or incline, you will alternate between faster or more intense bouts and easier recovery periods.
HIIT treadmill workouts are a specific type of treadmill interval workout wherein the intensity of the intervals is vigorous enough to increase your heart rate to at least 85% of your maximum.
It is also possible to do a HIIT treadmill workout doing incline walking, depending on your fitness level.
Very fit individuals may not be able to elevate their heart rate high enough even with a brisk walking pace and an incline of 15% grade.
The Benefits Of Treadmill Intervals
Treadmills are an especially effective tool for HIIT running workouts because when you are running outside, you have no control over the incline—the slope of the road is what it is.
You also have to deliberately work to maintain a certain speed, often looking at your GPS running watch to ensure you are hitting the right pace.
On a treadmill interval workout, you can program your specific speeds and inclines and all you have to do is keep up.
For example, I absolutely love doing intervals on my Bowflex Treadmill 22.
You get all of the premium features you would expect from the best home treadmills like a 22-inch immersive HD touchscreen. I can stream guided interval running workouts from the JRNY app (you get a free year!), and the treadmill adjusts according to the interval workout I choose.
There is the ability to run up to 12 miles an hour (5 min/mile) or adjust the incline and decline from -5% decline to 20% incline!
This maximizes the muscles worked by the treadmill and the versatility in the types of running and walking workouts I can do, and once I pick a workout, I “set and forget” and the treadmill takes care of changing everything for me.
Additionally, with a treadmill workout, you can watch the time right in front of you on the display rather than needing to check your watch, making it easier to know when to shift gears between hard bouts and recovery segments.
Interval treadmill workouts are inherently challenging because you are pushing your body with bouts of harder efforts.
This is especially true in the case where you are doing HIIT treadmill intervals because, by definition, the goal should be to elevate the heart rate to at least 85% of your maximum heart rate or 90% of your VO2 max.1Atakan, M. M., Li, Y., Koşar, Ş. N., Turnagöl, H. H., & Yan, X. (2021). Evidence-Based Effects of High-Intensity Interval Training on Exercise Capacity and Health: A Review with Historical Perspective. International Journal of Environmental Research and Public Health, 18(13), 7201. https://doi.org/10.3390/ijerph18137201
Even if you are doing pace-based intervals or incline walking interval treadmill workouts, there are numerous benefits of using this approach to treadmill exercise rather than steady-state treadmill workouts.
Of course, the specific benefits you will glean by doing treadmill intervals will depend on your fitness level and the type of treadmill interval workout you are doing.
That said, here are some of the top benefits of treadmill interval training:
- Helps you become a faster runner
- Helps beginners build up to running longer without stopping and without overly taxing the cardiovascular and musculoskeletal systems
- Allows you to do hill training and strengthen your muscles and power for uphill running if you do incline treadmill workouts
- Increases VO2 max and lactate threshold2Atakan, M. M., Li, Y., Koşar, Ş. N., Turnagöl, H. H., & Yan, X. (2021). Evidence-Based Effects of High-Intensity Interval Training on Exercise Capacity and Health: A Review with Historical Perspective. International Journal of Environmental Research and Public Health, 18(13), 7201. https://doi.org/10.3390/ijerph18137201
- Increases metabolic rate for up to 14 hours after the workout in the case of treadmill HIIT workouts3KNAB, A. M., SHANELY, R. A., CORBIN, K. D., JIN, F., SHA, W., & NIEMAN, D. C. (2011). A 45-Minute Vigorous Exercise Bout Increases Metabolic Rate for 14 Hours. Medicine & Science in Sports & Exercise, 43(9), 1643–1648. https://doi.org/10.1249/mss.0b013e3182118891
- Trains your anaerobic system as well as aerobic system
- Burns calories efficiently4Zhang, H., Tong, T. K., Qiu, W., Zhang, X., Zhou, S., Liu, Y., & He, Y. (2017). Comparable Effects of High-Intensity Interval Training and Prolonged Continuous Exercise Training on Abdominal Visceral Fat Reduction in Obese Young Women. Journal of Diabetes Research, 2017, 1–9. https://doi.org/10.1155/2017/5071740
- Helps reduce body fat5Viana, R. B., Naves, J. P. A., Coswig, V. S., de Lira, C. A. B., Steele, J., Fisher, J. P., & Gentil, P. (2019). Is interval training the magic bullet for fat loss? A systematic review and meta-analysis comparing moderate-intensity continuous training with high-intensity interval training (HIIT). British Journal of Sports Medicine, 53(10), bjsports-2018-099928. https://doi.org/10.1136/bjsports-2018-099928
- Provides an effective workout in an efficient amount of time6Wewege, M., van den Berg, R., Ward, R. E., & Keech, A. (2017). The effects of high-intensity interval training vs. moderate-intensity continuous training on body composition in overweight and obese adults: a systematic review and meta-analysis. Obesity Reviews, 18(6), 635–646. https://doi.org/10.1111/obr.12532
- Provides a more engaging treadmill session so that the treadmill is less monotonous and the time passes quickly in a more enjoyable manner7Gillen, J. B., Martin, B. J., MacInnis, M. J., Skelly, L. E., Tarnopolsky, M. A., & Gibala, M. J. (2016). Twelve Weeks of Sprint Interval Training Improves Indices of Cardiometabolic Health Similar to Traditional Endurance Training despite a Five-Fold Lower Exercise Volume and Time Commitment. PLOS ONE, 11(4), e0154075. https://doi.org/10.1371/journal.pone.0154075
- Provides a way to improve your mental strength and focus because you have to push yourself and stay present with each hard interval on the treadmill
Factors That Affect How Many Treadmill Intervals You Should Do
There isn’t a set number of treadmill intervals everyone should do for a running or walking treadmill workout.
The factors that affect how many treadmill intervals you should do and how to structure those intervals include the following:
#1: Your Fitness Level
Beginners should start with just a few running intervals on the treadmill unless they are very short and you are using the run/walk approach.
As your stamina increases, you can add more running intervals and decrease the frequency or length of the walking intervals.
#2: Interval Length
The main factor that will impact how many treadmill intervals you should do is the length of the intervals in time or distance.
This is closely intertwined with the intensity of the intervals, which will be discussed next.
Of course, the longer the hard treadmill intervals, the fewer intervals you should do in a given treadmill workout because each interval will take up a more substantial portion of your desired exercise duration.
#3: Interval Intensity
The faster or more intense the intervals that you are walking or running on the treadmill, the fewer you should do unless they are quite short.
Distance and speed/grade of the treadmill have to be considered in concert with one another when developing the best interval treadmill running workout or best treadmill incline walking workout for your fitness needs.
Treadmill intervals running may increase the speed, incline, or both during the hard intervals, depending on the primary goal of the workout.
#4: Goal of the Workout
The number of walking or running treadmill intervals you should do per workout will depend on the goal of the workout.
If you are trying to replicate a tempo run or threshold intervals, you will likely do fewer treadmill running intervals whereas if you are working on speed or trying to do a HIIT treadmill workout (high-intensity interval training), you will likely have much shorter but faster or steeper incline treadmill running intervals.
How Many Treadmill Intervals Should I Do To See Good Results?
As we saw, there are numerous factors to consider when structuring an interval treadmill workout for runners or a treadmill walking interval workout.
To that end, counting the number of treadmill intervals that you do in a treadmill running or walking workout is often not the best metric by which you should “measure“ or structure your session.
Of course, there are plenty of exceptions to this in which choosing a specific number of treadmill running intervals and/or treadmill walking intervals will be the most logical way to plan the best treadmill workout for your needs.
For example, if you want to do a fartlek interval on the treadmill, you might decide to do 10×1 minute hard followed by one minute easy after a brief warm-up and followed by a good cool down.
In this case, setting your goal to be 10 intervals on the treadmill each lasting one minute makes sense and will help you countdown or keep track of your progress during the treadmill run.
When I am working as a running coach with new runners who want to do a workout on the treadmill rather than outside, I do often prescribe their treadmill running program for the day based on a certain number of treadmill intervals for a certain length of time rather than distance.
I have found that for beginners, just focusing on getting through a certain number of treadmill running intervals or using a run/walk treadmill interval workout approach helps them worry less about pace and helps build confidence and stamina more effectively.
I will typically structure their training week with one of the run/walk interval workouts having fewer treadmill intervals that last longer and one interval workout on the treadmill with shorter intervals but more of them.
Then, the following week, I might keep the same duration of the long and short intervals, respectively, and either add more intervals of the same length or decrease the rest or walk time in between each interval.
In this way, keeping track of the number of intervals you are running can be helpful or motivating.
However, I generally find that counting running intervals on a treadmill is less useful for advanced runners for whom we might replicate outdoor running workouts on a treadmill for inclement weather or when they need to do hill training for an upcoming race but don’t have a hilly area outdoors to run.
In these situations, we might have a target distance or time for the intervals or use a treadmill pyramid interval workout with minutes or distance (increasing and then decreasing the length or distance of each hard interval).
Here, there isn’t much merit in comparing how many intervals you do in one treadmill interval workout versus another because the distance, speed, and goal of the workout might be totally different.
Instead, we might key in on monitoring improvements in the pace for the hard efforts or the distance covered in a timed interval as a metric of progress.
Learn more about HIIT training here.
