Polarized training: RIP threshold training

Wow, who would have thought that the Periodization series would be the gift that keeps on giving? But here I am, again, answering questions; not that I mind. Actually, polarized training is not really another periodization model, but rather an approach to training within an overall plan. The idea being that training is split into about 80% high volume, low intensity training, and 20% low volume, near maximal/maximal intensity training; obviously, this eliminates the middle threshold intensities altogether. Recent research lends strong support for this dichotomous training method. Here’s what you should know.

What we can learn from elite athletes

Polarized training (POL), also termed High-Low by some, is actually supported by retrospective training analyses of elite athletes, many of whom spend about 75% at low intensities, and 10-15% at very high intensities (Laursen 10). Yet, many coaches continue to prescribe and market various forms of threshold training; e.g., AT, LT, and Sweet spot, to name a few. I am continually astounded by how many athletes still believe that something magical happens if they train at or just below lactate threshold, and I blame the popular coaching community for perpetuating this nonsense. The fact is, and the research supports the use of high-intensity interval training (HIT – I’ll lump sprints in here too) to improve that final 1-5% in well-trained athletes. In his 2002 review, Laursen  & Jenkins discuss how the volume and intensity improve performance, and why HIT is really the only way for highly trained persons to continue to improve. So the idea that (a large portion of ) training under that intensity makes little sense, particularly for time strapped athletes. Is it any wonder why Chris Carmichael had someone ghost write the time-crunched books?

Research on Polarized Training

There are a few good published papers out there on POL, but I don’t want to turn this post into a review of POL research. Rather, I hope to point out a few salient findings and discuss whether you may want to apply POL in whole or in part to your training. If we look at the research as a whole (all the way back to the Stepto 99 paper) we see one common thread; HIT improves low, moderate, and high-intensity endurance performance (ie, duration, threshold, 5 k to 40 k time trial performance). We also note that the relative proportion of HIT needed is small (20% or less). Both of these point to the positive potential of POL. The most compelling support, however, are the studies actually comparing POL with other forms of training; I’ll focus on the two most recent. I should make one note about how difficult it is to find athletes willing to participate in any type of training study like those outlined below. Both of these studies did a good job in comparing the actual training they wanted to evaluate.

Six weeks of a polarized training-intensity – Neal et al. 2012

Sweat Science did a nice review of this paper that I’ll extend a bit more. Here is what the study looked like:

12 trained male cyclists who averaged about 7-8 hrs of training each week took part. Their peak power was ~370 W (4.7 W/kg) and their LT power was ~ 302 W (3.9 W/kg); basically, they were fit, but not elite, which for the average person makes this study more relevant. This was a cross-over study, which means all the subjects did both training interventions. Also, prior to each training period, subjects detrained for 4 weeks, so that their fitness level prior to training was nearly the same each time; a big positive boost! After detraining, subjects performed one of the following protocols:

  • Polarized model: 80% low-intensity; 0% medium-intensity; 20% high-intensity; 381 min, 517 TRIMP
  • Threshold model: 57% low-intensity; 43% medium-intensity; 0% high-intensity; 458 min, 633 TRIMP

LOW is Zone 1 = <65% of peak power output (PPO), and under threshold

MEDIUM is Zone 2, ~65–80% of PPO, at tempo or threshold

HIGH is Zone 3, typically >80% of PPO, and above threshold

  • Incidentally, prior to the study, their training breakdown was 53% low-intensity, 38% medium-intensity, and 9% high-intensity.

Training involved 3 days per week in the lab for 6 weeks. The researchers tried to match time spent in Zone 1, so the threshold group did a total of 7.5 hours per week of training, while the polarized group did 6.4 hours per week. Without going into too much more detail, the design was good and the statistics run were appropriate.

Again, Sweat Science did a nice overview of the findings. However, I’d like to explain some of the results they overlooked. First, the threshold  group trained an hour more, and accrued a greater training load, measured as TRIMP (the precursor to Training Peak’s TSS). Also of note, both training programs improved fitness over the course of six weeks and both yielded similar increases in key endurance related muscle proteins; in other words, you’ll get fit. However, that’s as far as any comparison can go. Taken together, POL produced better results in nearly every test variable (summarized in Table 3). Specifically (and statistically significant), POL led to more than a 2 min improvement in 40 k TT time, 9 W improvement in LT, 8 W in peak power, as well as almost a minute greater performance at 95% peak power. These results are made more meaningful by the inclusion of effect size and Cohen’s descriptor; in simple terms moderate to large effects likely will yield real world results, while trivial are as they sound. One other note on these results is the rather large amount variation (+) in the threshold group. This suggests to me that trained cyclists are more likely to “respond” to HIT than they are to threshold training, which may actually relate to the training stimulus (ie, intensity) rather than load.

Neil F3

Polarized training has greater impact on key endurance variables – Stöggl & Sperlich 2014

In a brand new paper published in January, Stöggl & Sperlich published a large scale trial comparing POL with threshold training (THR), as well as HIT and high volume training (HVT) – think base miles, over the course of 9 weeks. As far as training studies go, this is as big as it gets, and I can only imagine the amount of work it took to pull this off. Forty-one (41) highly trained XC skiers, cyclists, runners and triathletes with VO2 Max values ranging from 57-75 ml/kg/min, which is very good, completed the study. Individuals were randomized into one of the four training groups, and there were no significant differences between those groups; cyclists and triathletes cycled for testing and training, while skiers and runners did run training. Again, this paper is a solid effort with good data.

Training programs are summarized in Figure 1 and Table 1, and used three training zones that were very similar to the previous paper. POL and HVT groups training about 11.5 hrs each week, while HIT and THR did about 7.5 and 9.5 hrs, respectively. The % breakdown in training was a bit more realistic, particularly for the POL group, where a about 6 hrs total were spent in Zone 2, still far less than the other groups. For full details on actual training, please review pg 2-3 of the paper.

Stoggl F1

Stoggl T1

In the interest of brevity, I am going to cut right to the fact that POL and HIT produced better results in most test variables. Specifically (Tables 2 & 3 in the paper), it is apparent that HVT does very little to improve performance, and can actually be detrimental to threshold and peak power/running speed. In other words, spending hours riding slowly is not just a waste of time, its may be counter productive and actually refutes the idea that you should build a huge base before intensity. But the data go a step further, indicating that POL training improved time to exhaustion (TTE) significantly more than HIT, and a similar amount as HIT for threshold (V/P4) and Peak V/P. This is impressive, and should persuade anyone to ditch both their threshold/sweet spot training altogether and stop piling on tons of base miles without including HIT. One final note on the results, HIT elicited a significantly larger drop in body mass, which may be particularly important for those interested in hitting peak performance.

Stoggl F3

Applying Polarized Training

What started as a simple follow up to some email inquiries led to some impressive findings here. While I am not at all surprised by the impact of HIT, the POL approach carries far more merit than I anticipated and has me considering examining the training programs I write to first see how closely they fall near the POL breakdown. It is important to note, however, I actually do not believe you need to abandon that middle, threshold training. Rather, these results should put things into realistic perspective, where if you had to make a choice you should go with the bigger bang for your buck training, HIT. I also believe that some sports demand time for “tempo” training, like running and road triathlon, in order to develop good pacing skills, become comfortable at race pace/position, and build physical and mental stamina. However, these two studies demonstrate that the high end training delivers more performance. And if nothing else, stop going slow in the off-season!

Here are my tips for implementing POL and HIT:

  • If your sport in characterized by lots of explosive attacks or efforts (e.g., road or MTB cycling, XTerra) then these training schemes are probably best.
  • If your time is limited (<10 hrs) there is no question, forget the HVT and THR and drop the hammer!
  • If your sport demands sustained (30+ min) of at or near THR efforts, then THR training makes sense, but not at the expense of HIT. Good examples here are 10 k for longer run races, Olympic and beyond triathlons.
  • For gods sake, if your coach tells you you need to develop a good base first, hire someone else!

Articles cited or otherwise influencing this article:

Esteve-Lanao 05 How do Runners train

Laursen 10 Training for intense exercise performance

Laursen 02 Interval training program optimization in cyclists

Neal 12 6 wk polarized

Seiler 09 the Role of Intensity and Duration in Endurance Training

Stöggl 14 Polarized Training

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2 Comments to “Polarized training: RIP threshold training”

  1. Gerry says:


    First I thought … wow – finally someone who understood the idea of POL training. But after reading to the end I am not sure anymore. You say don’t drop threshold, if your sport requries more than 30min do threshold etc etc.

    No, really not. Drop threshold as much as you can, you will get thresh time anyhow, more than you should (10%), and if it is only during races. Maybe do some thresh shortly before the race to get a feel for the tempo, but do not actually ‘train’ in it.

    Threshold training is bad. Why ? Because at threshold you already produce enough hydrogen ions inside the cells that damage your mitochondria if exposed too long.

    Low intensity training builds your mitochondria and slow twitch muscles, high intensity training builds your cardio system and your fast twitch muscles. That is all you need. No matter what the distance of your race.

    The often used wording ‘teach your body to handle lactate’ to improve power at threshold is complete bullsh**. Lactate is not your enemy it is a result of neutralizing the aggressive hydrogen ions that are produced during anaerobic energy production. What you need to improve threshold is

    A – a powerful aereobic system (many mitochondria in your muscle cells)
    B – a powerful cardio system to transport oxygen to the cells.

    If you have got that, you will have more power without need of anaerobic energy production. This will improve your threshold power and be the key performance enhancer for everything lasting longer than 1 minute.