Runners tend to be driven, goal-oriented, and competitive, so it’s only natural that most runners want to know how to get faster. There are various training methods for distance runners, many designed to help runners gain speed.
Some runners run high mileage at a very low intensity, and some try to incorporate many higher-intensity interval sessions, such as tempo runs and threshold intervals, into their training plans.
Another popular approach to programming running workouts is polarized training.
Polarized training is a training approach that involves focusing on keeping your easy runs easy and your hard runs hard and eliminating runs that fall in the middle.
In this guide, we will explore the benefits of polarized training and how to implement it in your running for optimal results.
What Is Polarized Training?
Much like the North Pole and the South Pole are on the extreme ends of the planet, polarized training involves splitting your intensity levels for your workouts into two extremes—very easy and very hard.
In other words, if you practice polarized training, you run your easy days easy and your hard days hard. The murky middle is all but eliminated, or at least minimized to nearly nothing.
Runners who engage in polarized training typically use an 80/20 approach, which means that they run 80% of their mileage at an easy, conversational pace (low-intensity training) and 20% of their mileage at a high-intensity.
For example, if you run 20 miles a week, you’d run 16 miles at your easy pace, and 4 miles would be high-intensity training.
Polarized training for endurance athletes emerged about 20 years ago in response to the observation that most elite endurance athletes were inherently practicing this method.
In other words, elite athletes who competed in endurance sports such as running, triathlon, cycling, and cross-country skiing spent the bulk of their training time doing low-intensity workouts, with some training time at a high intensity and little to no time in the murky middle.1Seiler, K. S., & Kjerland, G. O. (2006). Quantifying training intensity distribution in elite endurance athletes: is there evidence for an “optimal” distribution?. Scandinavian Journal of Medicine and Science in Sports, 16(1), 49–56. https://doi.org/10.1111/j.1600-0838.2004.00418.x
How Does Polarized Training Impact Endurance Performance Compared To Other Training Methods?
Many runners fall into the trap of running roughly the same pace every day, or run their easy runs too hard.
When I first started running, I was guilty of the latter. I was always trying to run faster than I could sustain, struggling to breathe easily and feeling like my heart was going to burst out of my chest. I was not getting any better this way, as I never recovered.
At best, many runners who try to incorporate speed workouts and long runs do end up with some distinction between paces for different workouts, but the magnitude of the difference is compromised by the fact that recovery runs aren’t easy enough to truly allow the body to recover fully.
If, for example, a high-intensity session takes you from feeling 100% to 60%, proper recovery doesn’t occur until you’ve bounced back to nearly 100%.
If your recovery runs the day after hard intensity work are run too fast and are too intense, instead of coming back to 90-100% or so, you might recover only about 80-85%.
As a result, when it’s time to do the next hard, speed workout, your body is already starting at a reduced capacity–you only have 80-85% of your effort to give to the workout instead of nearly 100%.
This, in turn, impairs your ability to run as hard or as fast during the training session, reducing your potential performance gains.
In practical terms, if you’re supposed to be running 6 x 800 at your 5K pace but you’re only able to muster about five reps, or you are falling 5 seconds off your pace for each interval, your body will not have as potent of a training stimulus for inducing positive fitness adaptations.
Proponents of this polarized training model argue that Zone 2 is not hard enough to effectively trigger the physiological adaptations required for improved performance and is also not easy enough to facilitate recovery or increase endurance.
Not only does falling into the trap of running almost every run at the same pace limit your overall progress, it can also lead to overtraining and overuse injuries, because the same stresses and intensities are placed on the body stride after stride, run after run.
In contrast, runners that train at drastically different paces—running speed workouts and slow runs—introduce more variability into their stride and the resultant stresses on bones, muscles, and connective tissues.
This can reduce the risk of injury and increase overall strength.
In sum, the main benefits of polarized training for runners include the following:
- Allows you to maximize your potential to perform well in hard workouts, thus leading to more rapid and significant performance improvements.
- Improves the ability to recover after workouts.
- Reduces the risk of overuse injuries.
How Do You Do Polarized Training?
Rather than the five different intensity zones used with the traditional heart rate zone model, the polarized training model divides training intensities into three zones.
Zone 1
Zone 1, the low-intensity zone, involves running at an easy, conversational pace that allows you to talk in complete sentences.
On a physiological level, Zone 1 would be any effort below your lactate threshold or ventilatory threshold and typically corresponds to a heart rate of 70-75% of your maximum heart rate.
Zone 2
Zone 2, moderate-intensity running, is a “comfortably hard” level, where you can probably speak in short sentences.
This zone equates to your tempo run or a threshold power effort and falls between your lactate threshold and critical speed.
In the polarized training framework, Zone 2 corresponds to a heart rate of about 80-85% of your maximum heart rate.
Zone 3
Zone 3, the high-intensity zone, is anything faster or more intense than your critical speed.
When running in Zone 3, you can only utter a couple of words at a time or very choppy sentences.
Your heart rate when running in Zone 3 is above 85% of your maximum heart rate.
With polarized training in its purest form, athletes usually spend about 80% of their training time in Zone 1 and 20% of their training time in Zone 3.
Still, polarized training has adapted to have several different iterations in distributions of training volume and zones over time.
Some coaches still consider themselves practicing polarized training, grouping zones 2 and 3 together, and therefore, athletes do 80% of their training in zone 1 and 20% in zones 2 and 3 combined.
Others morph polarized training further by training 70% of the time in Zone 1, 20% of their mileage in Zone 2, and 10% in Zone 3.
This should be distinguished as pyramidal training, but the term polarized training is still often ascribed.
Does Polarized Training Work for Runners?
Studies have shown that polarized training for runners can be an effective way to improve performance and get faster over time.
For example, one study2Muñoz, I., Seiler, S., Bautista, J., España, J., Larumbe, E., & Esteve-Lanao, J. (2014). Does Polarized Training Improve Performance in Recreational Runners? International Journal of Sports Physiology and Performance, 9(2), 265–272. https://doi.org/10.1123/ijspp.2012-0350 compared the effects of a polarized training program and more traditional running training program on 10K running performance over the course of 10 weeks.
The researchers split 30 endurance runners into one of two groups.
The polarized training group did 77% of their mileage in zone 1 (defined as an intensity below ventilatory threshold), 3% of the mileage was run in zone 2 (defined as an intensity between ventilatory threshold and respiratory compensation threshold), and 20% of the mileage was in Zone 3 (defined as high intensity above respiratory compensation threshold).
The “between thresholds endurance training” group ran nearly the same amount of mileage in Zone 3, but the distribution of training time in zones 1 and 2 were quite different.
This group ran 46% of their workout time in Zone 1, 35% in Zone 2, and 19% in Zone 3.
To quantify and qualify the type and time spent in each training zone, runners wore heart rate monitors and their exercise heart rates were compared to their baseline testing in which their ventilatory threshold and respiratory compensation thresholds, and associated heart rates, were identified.
After 10 weeks, both groups significantly improved 10K run times. Although not statistically significant, the polarized training group did improve more than the more balanced training group.
Runners in the polarized training group improved their performance by 5%, whereas the other group improved by 3.6%.
This difference in improvements between the two groups equated to roughly 41 seconds, meaning that runners who had followed polarized training reduced their 10K run times by an additional 41 seconds over the other training group.
Moreover, when the researchers took a deep dive into which runners in the polarized training group had polarized their training most dramatically, those who had the least training time in Zone 2 had the greatest performance improvements.
Another study compared the effectiveness of four different approaches to training on improvements in aerobic threshold capacity (VO2 max) over the course of nine weeks.
The researchers split 48 highly trained endurance athletes (runners, cyclists, triathletes, and cross-country skiers) into one of four training programs: high-volume training, “threshold-training,” high-intensity interval training (HIIT), or polarized training.
Out of all four approaches, the athletes in the polarized training group demonstrated the greatest increases in VO2 max, time to exhaustion, and peak velocity/power after the nine weeks.
Polarized training increased VO2 max by 11.7%, time to exhaustion by 17.4%, and peak velocity/power by 5.1%.
Not only did polarized training yield significant improvements in endurance performance parameters, but the other training programs were found to not cause improvements in any of the variables measured.
If you find you aren’t making the improvements you’d hope to with your current training program, it might be worth following the lead of many elite runners and jumping on the polarized training bandwagon.
As a certified running coach, I use polarized training with most of my athletes, as I have found it provides the best results. It’s hard to stay in that easy recovery zone, but it’s worth the effort in the long run.
Although you don’t have to strictly do away with every tempo run or moderate-intensity workout, see if you start to feel fitter and faster if you focus on taking your easy days really easy and pushing yourself to the max in your hard workouts.
If you are looking to put together a successful training plan for your next race, check out this next guide on periodization:
