How To Correctly Polarize “80/20” Your Training

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It’s time to talk about polarized training—a popular training concept often referred to as the “80/20 principle.”

Unfortunately, many athletes have misinterpreted and misapplied this strategy, so we will be reviewing this training philosophy in this episode. Tune in if you want to learn what polarized training truly entails and the benefits of this practice, the research behind the effects of 80/20 training, how you can practice this method correctly, and more!


The leading endurance athletes in the world do the vast majority of their training at comfortable paces. [01:32]

You can monitor your exercise heart rate using the talk test by reciting the alphabet or talking to a friend. [03:43]

The 80-20 concept means that 20% of your workouts are characterized as high intensity or difficult session. [05:00]


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Brad (00:00):
Welcome to the Return of the Primal Endurance Podcast. This is your host, Brad Kearns, and we are going on a journey to a kinder, gentler, smarter, more fun, more effective way to train for ambitious endurance goals. Visit primal to join the community and enroll in our free video course. Unfortunately, many athletes have misinterpreted and misapplied.

Brad (00:32):
Hello, listeners, viewers. Let’s talk about polarized training. The popular training concept has also been referred to as the 80-20 training principle, and this is a strategy or a philosophy where you vary the intensity of the intensity of your training to emphasize comfortably paced training 80% of the time. And then 20% of the time is when you go hard. Notably, what you eliminate are those in-between workouts that are kind of hard, that exceed your fat max heart rate are in the black hole, or the no man’s land, where you are immersed into a pattern of chronic cardio rather than expertly polarize your training and get the aerobic conditioning benefits. And then when it’s time to go hard, you’re rested, you’re fresh, and you can deliver good performances because you’re not continually dragging ass through insufficient recovery because most of your workouts are slightly too hard.

Brad (01:32):
The polarized training concept, or the 80-20 concept has notably been promoted by a leading exercise physiologist named Dr. David Seiler. He’s an American, but he is based in Norway. He has studied the training schedules of an incredible variety of elite endurance athletes across numerous sports. This includes elite runners, professional cyclists, professional triathletes, the Olympic cross country skiers, uh, rowers speed skaters and swimmers. And what he discovered was this consistent theme where the vast majority of workouts of the leading endurance athletes on the planet, not just from recent research from Seiler, but this goes back over 60 years, dating back to the great Arthur Liddiard, training the distance runners in New Zealand who came to dominate in the 1960s in the Olympic Games in middle distance and long distance running. He was training them with this, uh, aerobic conditioning concept, and littered was the pioneer.

Brad (02:34):
Dr. Phil Maffetone deserves credit as a pioneer as well. And now we have decades of practical application of this philosophy that the leading endurance athletes in the world do the vast majority of their training at comfortable paces. And this can be defined as at or below fat max heart rate. Uh, this would be in zone one or zone two, uh, in the modern terminology. So only a small slice of the pie of their weekly or monthly training schedules are considered to be challenging high intensity sessions. And we’re gonna talk about Eluid Kipchoge and the great analysis that’s been done on his training schedules and what we know him as the greatest marathon runner of all time. He broke the two hour barrier in that magnificent performance in 2019. He has two Olympic gold medals and his training’s been scrutinized heavily by exercise physiologists, where he’s very much in this mode of doing the vast majority at a very comfortable paces.

Brad (03:43):
So, notably missing from the training of the elite athletes in every endurance sport over the past 60 years plus is this chronic cardio where the workouts are medium to difficult. Unfortunately, and shockingly, the vast majority of recreational endurance athletes are indeed doing just that, where they are routinely exceeding their fat max limit because it’s so frustrating to go that slow and you don’t really feel like you’re getting a workout stimulation unless you speed it up a bit and get a good sweat going and start to lose your breath. So, I’ve talked about the importance of monitoring your exercise heart rate if you’re an endurance athlete every single time you exercise, because it is difficult to intuitively just stay comfortable enough to stay under fat max. But even if you don’t have the, the strap on and monitoring, uh, your, your exercise heart rate, the somewhat reliable test is to, uh, use your the talk test where if you become short of breath when you’re trying to recite the alphabet or carry on a conversation, you can bet that you are drifting above that fat max heart rate.

Brad (05:00):
So, the way to train for endurance sports is to do so at very comfortable heart rates interspersed with some strategic high intensity sessions that will prepare you for what you’re facing in competition and help you increase your speed once you have developed a fantastic aerobic conditioning base. So, 80-20, it is 80-20. 80-20. Unfortunately, many, uh, athletes have, uh, misinterpreted and misapplied the concept because when you think about it, there’s many different ways to define what quote unquote 20% of your training is. So this 80-20 concept is not 20% of your total workout hours going hard. That’s vastly too much, uh, stress and too much time at the elevated heart rates. It’s not 20% of your total weekly mileage that’s performed at high speeds either, but the truth is, it’s 20% of your workouts that are characterized as a high intensity or difficult session.

Brad (06:12):
So 20% of the workouts that have any feature of high intensity effort. And for the most part these workouts are interspersed with a lot of comfortable paced exercise such as warmup, cool down, jogging during the rest intervals in between your interval where you work hard. So forget about the calculations that you’re running 40 miles a week, therefore you can, you can slam it for eight miles, 20% of that. That’s not what this concept is. As Dr. Seiler asserts quote, what we are trying to achieve is a polarization of the stress of the daily training sessions. On most days, we have an intention to achieve a training session without triggering a big stress response. So 80% of your workouts are entirely aerobic and comfortably-paced and minimally stressful. And 20% of your workouts feature elements of high intensity. So consider, I’m gonna do a practical example here where you’re going out for an interval session on one of your five workouts over the week.

Brad (07:28):
So that’s 20%, right? You have four workouts that are comfortably paced, and then you have one workout that includes high intensity. So, if you get into this workout, you’re talking about, uh, this many minutes of warming up, this many intervals, perhaps you’re doing, uh, eight times, 400 meters on the running track and then you’re, uh, jogging for a few minutes in between those 400 meter efforts that take you a minute and a half. Uh, and overall you’re accumulating, let’s say the workout takes 45 or 60 minutes, but if you’re doing, um, eight times 400 meters in a minute and a half, that’s only 12 minutes of hard effort at the workout. So if you were to do an 80-20 calculation of the total training time, let’s say you’re running an hour at each of those comfortably paced workouts, you’re talking about a 96% of total training time is comfortably paced, and only 4% consisted of those intervals running 400 meters fast eight times.

Brad (08:37):
Um, if you misapply and misinterpret what this 80 20 concept is all about, you’re going to vastly exceed, uh, the appropriate dose of high intensity exercise over the total duration of your weekly workouts. And remember also, I don’t know if this has been talked about enough, but Dr. Seiler is working with the top endurance athletes in the world and coming back with the insight that they are 80% comfortable and 20% high intensity. But arguably, if you are not an elite level endurance athlete with a phenomenal aerobic base and incredible genetic gifts for endurance performance and recovery, perhaps you might want to consider a 90-10 pattern or a 100 and zero pattern, especially as detailed in many of Dr. Maffetone’s books. If you show signs of, uh, insufficient overall general health. If you show signs of, for example, the accumulation of visceral fat around the abdomen, you are not fit to conduct any anaerobic intensity exercise until you get your health and your metabolic body composition in order, because stressful exercise can exacerbate the problem of visceral fat accumulation by chronically overproducing stress hormones, and someone who’s not, who’s ill-adapted for that kind of high intensity work.

Brad (10:05):
So the first objective is to build a strong aerobic conditioning base, perhaps with months and months on end of strictly aerobic exercise and zero anaerobic exercise. So when you show progress and you are improving your times in the MAF test, which I’ve talked about in many other podcasts where you set your heart rate at Fat Max and complete the same course over time, you repeat the tests over and over every three or four weeks when you show improvement, when you show good foundation of general health, when you’re not laden with prescription drugs going into your body, Dr. Maffetone contends that this can interfere with aerobic development. That’s when you have established a base and then can dabble in high intensity anaerobic exercise for a maximum of 20% of your total weekly training sessions. So please understand what 80-20 is all about and apply it correctly, and don’t even go there until you got a hundred percent awesome aerobic conditioning base. If you have any further questions about this please email I’d love to hear about your results with, uh, polarized training, and we can continue to talk about this very, very important topic. Thanks for listening, watching.

Brad (11:28):
I hope you enjoyed this episode and encourage you to check out the Primal Endurance Mastery course at This is the ultimate online educational experience where you can learn from the world’s great coaches and trainers diet, peak performance and recovery experts, as well as lengthy one-on-one interviews from several of the greatest endurance athletes of all time, not published anywhere else. It’s a major educational experience with hundreds of videos, but you can get free access to a mini-course with an ebook summary of the Primal Endurance Approach and nine Step-by-step videos on how to become a primal endurance athlete. This mini course will help you develop a strong, basic understanding of this all-encompassing approach to endurance training that includes primal-aligned eating to escape carbohydrate dependency, and enhance fat metabolism. Building an aerobic base with comfortably paced workouts, strategically introducing high intensity strength and sprint workouts, emphasizing rest, recovery, and annual periodization, and finally, cultivating an intuitive approach to training. Instead of the usual robotic approach of fixed weekly workout schedules, just head over to Primal Endurance Fit and learn all about the course and how we can help you go faster and preserve your health while you’re at it.

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