The Two Best Ways To Build Endurance As Fast As Possible (Without Destroying Your Body) – Part 1

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Welcome to the second chapter in Part 2 of Beyond Training: Mastering Endurance Health & Life.

In this chapter, you're going to build upon your knowledge from the last chapter about training intensities and zones, and you're going to discover why most endurance athletes train the wrong way.

After all, the right way to build endurance can be confusing.

Should you use the long, slow aerobic “Maffetone method” style of steady and patient training, popularized by Mark Allen and used by many Ironman and marathoner professional endurance athletes (12)?

Should you use the CrossFit Endurance approach of high-intensity interval training combined with teeth-grittingly difficult workouts and weight training sessions?

Should you use some hybrid “polarized training“, with generous amounts of aerobic sessions combined with short smattering of very hard efforts here and there (8)? 

Or should you use something completely different?

You're about to find out – and also learn why endurance athletes are lazy, why the lens you see your training through matters, and the two best ways to build endurance as fast as possible.

And by the way, before we jump into this chapter – I wanted to mention that on April 27, Saturday, at 6pm PST, I'm doing an “Ask Me Anything About Minimalist Triathlon Training” live video spreecast – in which you'll be able to ask all your questions about the type of training protocols you see here. The video is for my Inner Circle members only (best 10 bucks a month you'll ever spend) – and it will also be recorded for replay for Inner Circle members – but I'd love to have you there too, and you can click here to join the Inner Circle now and access it!

OK, let's jump in…


The Black Hole

There's a big, big problem in endurance sports.

It's a hole.

A black hole.

The black hole goes something like this…

The runner who rolls out of bed 3-5 days a week to run 45-60 minute at the same speed every time.

The triathlete who hops in the pool at lunchtime and swims 30 minutes steady every time.

The cyclist who goes out every weekend and rides at a steady cadence and speed for 2 hours every time.

Same speed. Same RPM. Same intensity.

Day-after-day, month-after-month, year-after-year. 

Perhaps its the thumb-sucking solidarity we find in knowing exactly what our bodies are going to feel like during every training session, perhaps its the fear of going too slow or too hard and somehow messing up our training or our bodies, or perhaps its just not knowing exactly what to do and simply doing figuring something is better than nothing.

Or perhaps endurance athletes are just lazy.


That's right: disguised behind all our spandex, fancy bikes, speedos, expensive shoes, and complicated training gadgets, we could just be lazy.

After all, compared to doing 30 minutes of hard, focused run intervals, it's easier to simply head out the door and slog through a mind-numbing 2 hour death march.

Compared to doing a structured series of swim drills, it's easier to just hop in the water, turn the brain off, and stare at the black line for awhile.

Compared to the laser-focus of an intense series of hill climbs, its easier to simply point the bike in one direction, hunch over the handlebars, and spin the pedals at whatever feels like a halfway decent pace.

Yes, I said it. We endurance athletes could just be lazy.

And regardless of whether its sticking too close to the tried-and-true, fear of failure or injury, lack of training knowledge, or pure laziness, endurance athletes simply accumulate the majority of training time at one single speed – the not-too-hard, not-too-easy, slightly near threshold training zone that makes you feel like you're working pretty hard, but not too hard, and perhaps just hard enough to get you a little bit fit.

Sound familiar?

I call it black hole training.

This training flaw has even been demonstrated in studies (5). For example, despite what a coaches' training plans may dictate, runners tend to run too hard  on easy days and too easy on hard days. Suddenly, training sessions that are supposed to be long and slow become fast and short. Workouts that are supposed to have variations in pace instead get performed at one single speed. As a result, most training sessions end up being performed at the identical intensity, workout after workout.

And the endurance athlete winds up racing at the same speed, season after season.

You may also be familiar with this type of training as “junk miles” or “single-speed” or “no man's land” training. In the previous chapter, I alluded to it as too much time in heart rate Zone 3 – just hard enough to deplete energy stores and damage muscles, but not quite hard enough to elicit any significant training response.

In a Bicycling Magazine article back in the 90's, cycling journalist and coach Fred Matheny described it this way:

“NML (no man’s land) workouts provide a kinesthetic sense of working hard but expose the rider to too much stress per unit gain. Instead, most base training should be guilt-producingly easy, and the top end, high-intensity-training should be very mentally hard, not sort of hard.” (13)

Simply stressing the same energy system over and over again not only results in a single-speed endurance athlete who can't go fast when it matters and never goes slow enough for recovery, but may also result in more rapid onset of overuse injury from repeated stress on the same joints.

For example,  research says 10-15% of the population is predisposed to something called “femoralacetabular impingement”, which can lead to labral tears and hip arthritis when coupled with a sport such as triathlon, which includes a high amount of hip jarring flexion during running and cycling (1).

Based on this, who do you think is going to have the higher risk of hip replacementthe triathlete who does every training session at the same speed (often on the same course) using the same joints and energy systems time after time, or the triathlete who mixes things up with some trail running, some track work, some hill work, some lateral movement, some cross-training and some recovery workouts?

Stressing the same energy system repeatedly also results in very high amounts of negative energy balance – especially when the majority of the training is done at or near threshold (which you're about to find out is not the case with most pro athletes but is the case in many recreational exercisers).

Studies have shown that this negative energy balance results in hormonal disruptions such testosterone deficiency and low drive in males, estrogen deficiency and low bone density in females, a wildly out of balance secretion of appetite disrupting hormones, and a host of other endocrine and chronic disease related health issues (6).

Yet another reason junk miles simply aren't worth it.

But wait! What about those stories of Kenyan marathoners and elite endurance athletes going out and completing long, slow training sessions with hour after hour at a single speed. Isn't that black-hole training?  Isn't that no man's land style junk miles performed at a single-speed? If so, it certainly seems to be working for those folks, right?

The fact is, that type of training you may be thinking of is actually not black hole training. It's something completely different. And you're about to learn what that is, why its much different than black hole training, and why it is one of the two best ways to build endurance.


The Pareto Principle

When you look at the training protocols of most elite endurance athletes, who typically train with 10-12 workouts and 15-30 hours each week, a distinct pattern emerges. Specifically, these elite endurance athletes spend about 80% of their training time below and about 20% of their training time above their lactate threshold (referred to as Zone 4 in the previous chapter).

This 80/20 pattern is so prevalent there's even a special name that has emerged in exercise science to describe it:

Polarized training.

When you look at endurance athletes from world champion rowers, professional marathoners, elite cyclists, and high-level triathletes, nearly all the top athletes competing in these sports are engaging in this kind of polarized training – in which they a large amount of time at relatively easy aerobic intensities, and occasionally throw in extremely hard bursts of high intensity.

And these athletes are spending very, very little time in the black hole region, that zone where you're training above an easy, aerobic pace, but below any pace that become extremely uncomfortable.

You may already be familiar with this 80/20 concept as the relatively famous “pareto principle“, which states that, for many events, approximately 80% of the effects come from 20% of the causes.

For example, one study (14) quantified the training intensity distribution of professional swimmers over an entire season, and found that these athletes swam about 77% of their swimming over the entire season at a purely aerobic intensity. Another study (3) investigated marathoners and found that during the 12 weeks leading up to the Olympic marathon trials, these athletes ran 78 % of their training at below marathon speed, only 4 % at marathon race speed, and 18 % above threshold.

And what about those Kenyan marathoners I alluded to earlier? Another study by Billat found that elite male and female Kenyan runners train with about 85 % of their weekly training volume completely below threshold.

The evidence goes on and on.

For example, in a study by (4) a group of sub-elite distance runners were randomly assigned to one of two training groups:

Group 1 performed performed 81% of their training in an easy Zone 1, 12% of their training in a moderate Zone 2 and 8% of their training in a high-intensity Zone 3 (note: don't get confused here – they were simply using 3 zones to quantify training intensity, rather than the 5 zones I used in the previous chapter).

In contract, Group 2 performed more threshold training, with 67% easy, 25% moderate, and 8% high intensity. In other words, Group 2 performed twice as much of their training at or near their lactate threshold. Interestingly, the authors reported that the athletes were actually not even able to exercise any more than about 8% of their time Zone 3, as it was simply too hard (that should give you a good idea of how hard high-intensity interval training is really supposed to be).

The total training volume was identical between the two groups.

But guess what? After five months of this protocol, the running performance of Group 1 was significantly higher – despite the fact that they had spent a great deal of time exercising at a much lower intensity than Group 2. 


But that wasn't an isolated study. In more research (9), a group of rowers were split into two different training groups: one group (low intensity) that performed nearly 100% of their training below 75 % VO2 max (a relatively low intensity). Meanwhile, the other group (mixed intensity) performed 70% of their training at those same low intensities, but did the other 30% of their training at a much higher intensity (above lactate threshold).

These two groups also performed nearly identical volumes of training.

And despite a significantly higher amount of training at a high intensity above threshold, the mixed intensity group didn't perform any better than the low intensity group. Sure, after 12 weeks of this protocol both groups had  improved performance and higher maximal oxygen consumption, but even though they spent a significantly higher amount of time in the pain cave, the mixed group didn't have any significantly greater gain in performance.

Bummer for the mixed intensity group.

So the take-away message so far is this: across a wide variety of endurance sports, studies have shown that the best endurance athlete athletes are actually performing about 80% of their training volume at a low intensity and only about 20% of their time training at a high intensity (15). 

And those high intensity efforts are very, very high – with relatively little time spent in the no man's land training zones where most recreational athletes train.

These athletes are getting enough low intensity training to build big aerobic engines and get lots of repetitions to engrain correct motor patterns for improving their movement efficiency and economy while also exposing themselves to just enough hard stress for significant cardiovascular and muscular adaptation.

So why if lots of low-intensity training is good, wouldn't more be better? In other words, instead of 80/20 why not 90/10, 95/5 or even 100/0 when it comes to training intensity percentage distribution? It turns out that multiple studies, especially in elite athletes, have investigated what happens when mild doses of high intensity interval training are added to a primarily aerobic training protocol, and the results are always favorable – and not surprisingly always close to the 20% mark with HIT dosing (10).

Stephen Seiler sums this all up quite nicely in a paper that appears in the International Journal of Sports Physiology and Performance:

“Numerous descriptive studies of the training characteristics of nationally or internationally competitive endurance athletes training 10 to 13 times per week seem to converge on a typical intensity distribution in which about 80% of training sessions are performed at low intensity (2 mM blood lactate), with about 20% dominated by periods of high-intensity work, such as interval training at approx. 90% VO2max. Endurance athletes appear to self-organize toward a high-volume training approach with careful application of high-intensity training incorporated throughout the training cycle. Training intensification studies performed on already well-trained athletes do not provide any convincing evidence that a greater emphasis on high-intensity interval training in this highly trained athlete population gives long-term performance gains. The predominance of low-intensity, long-duration training, in combination with fewer, highly intensive bouts may be complementary in terms of optimizing adaptive signaling and technical mastery at an acceptable level of stress.”

So despite the fact that it feels very rewarding to roll up your sleeves and head out to the door to hammer at or near your threshold for a morning or lunchtime run, or ride at a steady “race pace” intensity for a few hours on the weekend, or swim lap-after-lap in the pool at your perceived Ironman intensity…

…it's simply the wrong way to train.


The Regression Problem

In all fairness, it actually is pretty darn hard to go easy when you're supposed to go easy and go really truly hard when you're supposed to go hard.

For example, the same research group I referenced earlier (4) tried to replicate the polarized training of successful elite endurance athletes with a program designed around more threshold training – but this time they tried the protocol on recreational runners rather than elite runners.

The intended intensity distribution for the two training groups was supposed to be 77% low, 3% moderate, and 20% high intensity in a polarized training group compared to  46%, 35% and 19 % in a “threshold” training group (7) (interestingly, those percentages in the traditional training group were based on American College on Sports Medicine (ACSM) recommended training intensity distributions). But heart-rate monitoring during the study revealed that the actual intensity distribution achieved by the recreational runners was 65%, 21% and 14 % in the polarized group and and 31%, 56% and 13 % in the threshold training group.

In other words, comparing the intended and achieved distributions in the study above simply highlights the fact that most of us, when left to choosing our own training intensities, tend to regress towards black hole training – even if we're supposed to do otherwise.


But Wait…Shouldn't Exercise “Break You Down” To “Build You Up”?

Hard exercise of any sort creates free radicals that cause some damage (called “oxidation”) to your muscles, cells and organs, and as your body repairs this damage, you experience biochemical adaptations that make you more resistant to future oxidative damage from high volume or high intensity training. As you train more, your body simply increases its production of natural antioxidants to control the free radicals you're producing (2).

Based on this enhanced repair mechanism and surge in natural antioxidants that occurs in response to tough workouts, it would seem to make sense that doing long sessions of Black Hole style training may actually result in making you  fitter and faster. 

However, although consistent oxidative stress is a critical component of getting fit, you must allow for a recovery period during which the body can bounce back adequately, and the key is to train in a manner that provides enough physical stimulus for you to get more fit, without causing overtraining or excessive oxidative stress. Rather than exposing the body to the same amount of stress and intensity day-in and day-out, you'll allow for enhanced free-radical fighting capacity by engaging in very hard days and very easy days.

My friend Armi Legge sums this up quite nicely in his article “The Truth about Extreme Exercise, Oxidative Stress, and Your Health“:

Most evidence indicates that if you train in a progressive, intelligent manner, with adequate recovery between workouts, you can build up to extremely high training loads and still be protected against potentially dangerous levels of oxidative stress. (Legge)”


That's A Wrap?

Well, that should about wrap it up, right?

After all, it turns out that it seems to work quite well to use this whole “Maffetone method” (12) style of A) finding your easy aerobic “fat burning” training zone and then B) spending a great majority of your time training in this zone with C) brief spurts of high intensity. I guess Mark Allen was onto something after all when he won those six Hawaii Ironman world championship triathlon titles.

It would seem that we now know the ultimate way to build endurance. End of story.

Hold your horses.

I don't know the last time you peeked at the training log of an elite endurance athlete, but…

Professionals train 10-15 times per week. That's not hours per week. That's times per week.

Most Ironman professional triathletes are swimming 20,000-30,00 yards per week. That's about 6-8 hours.

They're also cycling 150-250 miles a week. That's another 8-10 hours. 

They're running 25-40 miles a week. That's another 4-6 hours.

Not to mention the additional hours spent core training, weight training, recovery training and of course, the additional hours spent preparing and eating the thousands of calories necessary to fuel these monster amounts of volume.

And don't think that this type of training volume is isolated to the crazy Ironman triathletes. Competitive marathoners, elite cyclists, top-level swimmers and all other professional endurance athletes literally devote their life to training.

Do you have 25-40 hours per week to train?

And do you have the self-control necessary to hold back the reigns and ensure that 80% of this training is in a very easy, aerobic intensity zone?

If so, then proceed, but proceed with the knowledge the majority of current training methods for a endurance events like an Ironman are derived from the training schedules, calendars, and lifestyles of professional endurance athletes who compete in the sport for a living, and train for 25-40 hours in a week.

And this means that if you have a busy life, a steady income, social obligations, kids, nightlife, and other hobbies, this style of polarized training may require you to potentially neglect your friends, career, family and life.

For me personally, this all relates to the lens that you see the world through: who cares if the training protocol works if it's bad for you or sucks time away from your career, friends and family? Unless you're a professional endurance athlete and this sport is how you're making money and feeding your family, then your precious time may be better spent elsewhere.

But that's your personal call.

Some recreational athletes do indeed have high disposable incomes, careers that are on cruise control, and the time to devote to 80% low-intensity, 20% high-intensity polarized training for many, many hours per week.

Or perhaps you're just the kind of person who thrives on being by yourself and spending long amounts of time training.

If so, polarized training is indeed one of the best ways to build endurance as fast as possible without destroying your body.



But as I alluded to in the title and opening to this chapter, there is also one other training method to build endurance properly.

And in part two of this chapter (which I'm furiously working on and should have ready for you in a couple days), you're going to discover what that other training method is.

You're also going to discover why it's dead wrong that the ultimate solution to the time conundrum of polarized training and the damage of black hole training is some kind of high intensity Crossfit-style hybrid or a complete neglect of any long slow aerobic training sessions.

Finally, you're going to learn the correct, practical methods for building endurance with polarized training and building endurance with the other method I'll teach you.

But until then…leave your questions, comments and feedback below!


Links To Previous Chapters of “Beyond Training: Mastering Endurance, Health & Life”

Part 1 – Introduction

-Part 1 – Preface: Are Endurance Sports Unhealthy?

-Part 1 – Chapter 1: How I Went From Overtraining And Eating Bags Of 39 Cent Hamburgers To Detoxing My Body And Doing Sub-10 Hour Ironman Triathlons With Less Than 10 Hours Of Training Per Week.

-Part 1 – Chapter 2: A Tale Of Two Triathletes – Can Endurance Exercise Make You Age Faster?

Part 2 – Training

-Part 2 – Chapter 1: Everything You Need To Know About How Heart Rate Zones Work

-Part 2 – Chapter 2: The Two Best Ways To Build Endurance As Fast As Possible (Without Destroying Your Body)

Also…for those of you who like to look ahead, the rest of Part 2 is going to include:

-Training, Food and Supplement Protocols for Testing, Tracking & Enhancing Endurance, Strength, Speed, Power, Balance, Range of Motion 

-Underground Training Tactics, including EMS, Cold Thermo, Overspeed, Isometrics/Superslow, etc.



1. Audenaert, E. (2012). Range of motion in femoroacetabular impingement. Acta Orthopædica Belgica, 73(3), 327-32.
2. Bessa, A. – Espindola, F. (2013). Exercise intensity and recovery: Biomarkers of injury, inflammation and oxidative stress. Journal of Strength and Conditioning Research, April(18)
3. Billat V, Lepretre PM, Heugas AM, Laurence MH, Salim D, Koralsztein JP (2003). Training and bioenergetic characteristics in elite male and female Kenyan runners. Medicine and Science in Sports and Exercise 35, 297-304; discussion 305-296
4. Esteve-Lanao, J. et al. (2007). Impact of training intensity distribution on performance in endurance athletes. Journal of Strength and Conditioning Research, 21(3), 943-9.
5. Foster C, Heiman KM, Esten PL, Brice G, Porcari J (2001). Differences in perceptions of training by coaches and athletes. South African Journal of Sports Medicine 8, 3-7
6. Fuqua, JS, Rogold, AD (2013). Neuroendocrine alterations in the exercising human: Implications for energy homeostasis. Journal of Metabolism, 0026-0495(13)00020-6.
7. Garber, C. (2011). Quantity and quality of exercise for developing and maintaining cardiorespiratory, musculoskeletal, and neuromotor fitness in apparently healthy adults: Guidance for prescribing exercise. Medicine and Science in Sports and Exercise, 43(7), 1334-59.
8. Hutchinson, A. (2013, February 9). Polarized training. Retrieved from
9. Ingham, S. (2008). Physiological and performance effects of low- versus mixed-intensity rowing training. Medicine and science in sports and exercise, 40(3), 579-84.
10. Laursen, P. (2004). The influence of high-intensity interval training on endurance performance in well trained cyclists. In D. D. Jenkins (Ed.), PhD Thesis (pp. 01-309). The University of Queensland: School of Human Movement Studies.
11. Legge, A. (2013, January 16). [Web log message]. Retrieved from
12. Maffetone, P. (2007). Want speed? slow down!. Retrieved from

13. Matheny, F. (1995). Stop training in `no man's land'. Bicycling, 36(10), 90.
14. Mujika I, Chatard JC, Busso T, Geyssant A, Barale F, Lacoste L (1995). Effects of training on performance in competitive swimming. Canadian Journal of Applied Physiology 20, 395-406
15. Seiler, S. (2010). What is best practice for training intensity and duration distribution in endurance athletes? International Journal of Sports Physiology and Performance, Sep;5(3):276-91.

Ask Ben a Podcast Question

45 thoughts on “The Two Best Ways To Build Endurance As Fast As Possible (Without Destroying Your Body) – Part 1

  1. Cassie says:

    Hi Ben,
    big fan! I was wondering *sorry in advance if you’ve been through this already and I’ve missed it* but I’m trying to heal myself from chronic inflammation. I was on antibiotics as a kid for four years and it’s basically screwed my body. I have all sorts of aches and pains, really poor posture, gut and skin problems, my focus and cognitive abilities are shot but I’m pretty positive I can heal all of this with the right diet. I really struggle with exercise and stuff. I was wondering if I were to follow all your recommendations like training, supps, fermented foods etc if there was anything else you would recommend? I’m only 26 and I feel like an unhealthy old lady already and just want to be able to feel and live a healthy life without aches, pains and shit physical abilities.

  2. Jim Carroll says:


    I really appreciate the research and effort you afford with your site. I have been making a comeback to training for middle distance after a break of 30 plus years. At 51, I want to get it right. I aim to go under 2.00 for the 800m. I really enjoy the ancestral studies and as an Aboriginal man myself, draw your attention to Mungo Man in South Western NSW, Australia. I visited the site with cultural activity and was amazed that 20,000 year old footprints in an ancient clay bed record a speed of 45 km/hr barefoot. Even more amazing is a one legged Aboriginal man hopping at high speed to keep up with the hunters. I have longed believed we as humans are capable of far greater feats, by studying the behaviours of those that walked the earth before us. The calf muscle is quite unique and effective for distance travel. I believe in an 80/20 mix of quite, relaxed aerobic and fight or flight 20 but staggered over multiple days.

  3. ruloor says:

    Excelente article, Well, I spoke from the point of view of a Cyclist Cat.3, no from a runner or triatlete point of view.

    First I said, CFE Is good IF YOU NEED a good formation., but in may case Veteran

    Cyclist almost 17 year hit the pedals.. I used a CFE program for almost 3 years in the last MTB race i don’t broke any records, even stay in the top ten of my categorie, the gap between the winner and I are 30min.

    So why this possible ¿? I was very committed with the program, I work very hard, and was very stressfull; but why can't improve my performance bike in a races???

    The answer is very simple, the CFE Program it’s no a good training program for cyclist, o in others words, The program don't help to recovery for a HIITS on Bike training so can’t get better gains, because You dont rest enough Period.

    Also the continuous weightlift exercices & gymnastic body weight exercises and WODs increse body mass….

    When I started the program my weigth are 160lbs for my 5’10” it’s ok for a average rider, but now a lose a some FAT and GAIN many muscles in Core, Chest, Arms, Back. And my weigth now is 176lbs. In others words I a heavy rider, and I note that in mediun and long climbs; In shorter climbs I have more power but in longest its very diferent.

    Now can jump more, lift more, run more, carry more, my body is more defined, more fitness, but my cycling it’s no better than 3 years ago.

    So, if you can improve your cycling for races, CFE its no the path.; But if you want a better fitness definitely its one the best choices.

    Now I focus more in my cycling and less in my WODs..I do a 1 o 2 wods in a week but focus in technique and strength, no in a Intensity, Reps or even wheigt
    But a CFE still be a very good option for a foundation season (2 or 3 months)

  4. Katrina Popham says:

    Really looking forward to catching up on the next chapter (I'm still behind)…This was very interesting and basically confirmed that I don't have enough hours in the day to train with a polarized plan. I really find it fascinating that more hours spent at the "near puking" level really doesn't translate into better performance. I'm one of those that feels like the harder I work, and more miserable I am while doing so, the better I should perform. I guess I'm going to have to get over that. Thanks for the education in training smarter!

  5. Jean-Luc says:

    Very interesting article indeed. It covers about all you have spoken about in podcast during the past few years on training smarter. This is a timely subject for me for I am looking forward to enroll into a half ironman next year . I am doing sprints & olympic triathlons and half marathon (using the plan developed by Jill and yourself). What fears me the most (well more my spouse) is the time it would take me weekly to train for such distance. I have not very much free time, being the father of 4 children. So I was asked to come up with a "plan" she would agree to let me achieve. Whitout revealing the details of the plans you made (such as dominator), what would be the weekly volume and how many weeks training for half ironman should take? Kind regards

  6. Eric Shadden Ŧ says:

    great job ben! very interesting chapter.

  7. Max says:

    Hey Ben. Great read! I tweeted out a question to you about the Furman Institute (Run Less Run Faster). My big question is this: how do they generate scientific data “proving” their method with what seems like the flip of polarized training as you described? Instead of 80-20% zone 1/2 to zone 4/5, FIRST seems to promote 80-20% zone4/5 to zone1/2. It’s three runs of high intensity (injuries?) and cross training two days also with some intensity seem to skip an aerobic foundation. I’m really confused. I’d love to hear you break it down for the average runner.

  8. Michele says:

    Great chapter, Ben. As someone who loves stats & facts, this all jives with me. As some whose been doing zone training for a few years now, I have some questions that maybe you'll get to later, but that I hope to see addressed:
    1. How much improvement, as a general matter, can you expect to see in speed or power with low intensity, zone 2 training? We all get frustrated with the slow pace of Z 2, but some people seem to improve their speed more quickly. I don't seem to get any faster, I.e., my heart rate doesn't seem to start to fall, which would seem to be part of the point of Z2 (to strengthen your heart/aerobic capacity so it actually doesn't work as hard).
    2. How often , if at all, during your training should you re-test your heart rate zones, or do they really change much during a training season. I think for some people, like me, we test our HRzones once, and that's it. I'm assuming those change (for better or worse depending on training or lack thereof) so that there will come a point when we're not actually training in the zone we thought we were.
    This may be stuff you're getting to, but they were questions that popped into my head as I was reading this. Great chapter!

    1. 1. How much improvement, as a general matter, can you expect to see in speed or power with low intensity, zone 2 training? We all get frustrated with the slow pace of Z 2, but some people seem to improve their speed more quickly. I don't seem to get any faster, I.e., my heart rate doesn't seem to start to fall, which would seem to be part of the point of Z2 (to strengthen your heart/aerobic capacity so it actually doesn't work as hard).

      Short answer is: not much. Which is why people who are naturally fast – like football players who become triathletes, for example – can do better with Z2 style training because they already have that strength/power/speed naturally.

      2. How often , if at all, during your training should you re-test your heart rate zones, or do they really change much during a training season. I think for some people, like me, we test our HRzones once, and that's it. I'm assuming those change (for better or worse depending on training or lack thereof) so that there will come a point when we're not actually training in the zone we thought we were.

      In the plans that I write for the, it's generally about every 3-4 weeks that we re-test. I find that HR Zones tend to fluctuate quite rapidly when training sessions are being changed (as in, going from "base" training to "build" training) etc.

  9. Francisco says:

    Ben, Thank you very much for the articles!

    My question is: Would a lower volume, polarized training program, work for a triathlete aiming a sprint triathlon rather then ironman tri?

    1. Not recommended to get the most bang for your buck…I'd use the strategies I'll highlight in the next chapter!

  10. John says:

    Loving the chapters Ben thank you. I'm training for my first ironman later this summer and following Don Fink's Be Iron Fit competitive training plan. I love that it explains the same methodology of training the majority of your time in a low HR zone as I was guilty of training in the black hole myself when not following a program. Although his plan only implements high intensity training of about 10% of total volumes your chapter eases my mind of thinking I'm doing too much too easy.

  11. lucas says:

    great reading ! keep up the good work, I'm learning a lot.
    in the recovery chapter will you write about injuries ? tendons, muscles…
    if not is there a good source of info ?

    1. yes, all that will be in the recovery chapter!

  12. Jeff Taylor says:

    Ben – I read very few fitness articles, because most of the materal is crap. However, I just read your "black hole" chapter and found it spot on. I'm looking forward to your alternative training method and will be checking back!

  13. Gary says:

    Another well written chapter. How does the Tri. Dominator plan compare to the levels of intensity and base that you have just written about? I am following the Tri. Dominator this year instead of following the typical Ironman approach. I can easily say I am feeling stronger and healthier than in the past. I am doing the long ride 80-100 miles next weekend and I am looking forward to a great ride and seeing how the intensity work bears out. It has paid dividends in the run, now for the bike. Keep up the good work and for continually searching on how to become the best that we be. Cheers Gary

    1. Hi Gary! adheres closely to the principles in the article above, so you're in good hands!

  14. Kevin says:

    Cannot wait for part two. I work 60 hours per week, commute 10 hours per week, married with two kids, and I try to compete in local running and cycling events. Part two is going help us weekend warriors.

  15. Sean Meehan says:

    Great stuff Ben. I’ve just moved from 16 years Rowing to Tri and often wondered why there was so much ‘steady’ endurance in Tri. I’m looking forward to Part 2!

  16. Ben,
    All I can say is thank you for taking the time and energy to put this together. It is well done and well rounded.
    Keep up the great work.


  17. Andrew says:

    In McGuff and Little’s book (Body by Science) there is a study mentioned about two groups, one who exercised at low intensity for a long time and the other group in short intense intervals with plenty of rest in between. I believe for a total time of 12 min for the interval group, can’t remember the details off hand.

    Anyway, the results of the study showed that both groups had the same fitness level measured by a 2mile time trial.

    My question is, has anyone studied triathletes training using just intervals? I.e. cutting out the 80% easy zone?

    1. Andrew…I'll be getting to your question in Part 2!

  18. Dan John says:

    Be sure to read all of Maffetone's work, Christian. His book, "Everybody is an Athlete," if you can find it, would be the best. His point, and I think it is true, is twofold: anaerobic book needs to built on aerobic, sure, but the aerobic work can be much more reasonable than most people think. Next, for overtrained people, Maffetone would agree with that earlier chapter on Chad and Kirsten…Kirsten being a better model. Overtrained people require what Mark Allen needed….a massive step back into low intensity.

    If I am wrong on this, forgive me, but I think I have it pretty close to Maffetone's insights.

    1. Christian says:

      Oh, don't get me wrong Dan. I'm currently building my base according to instructions in The Big Book of Endurance Training and Racing. I'm getting results but find it EXTREMELY frustrating not being able to go faster. I'm an endorphine junkie with 24 years of weight training behdind me, and switched to endurance training a couple of years ago. But I had a LOT of overtraining injuries and my research led me to Maffetone. I haven't had an injury since. But I'm still far from happy with the pace and distances I can cover. I'm REALLY looking forward to Ben showing me an alternative method of training here which would allow me to train harder without increasing the risk of injury!

      I'll have a look if I can get my hands on the book you refer to, thanks for the tip!!

  19. Bill Dennis says:

    Ben, I was getting ready to purchase one of your plans but after reading this article on black hole training has me thinking I should hold off until you are ready to publish this new training program. When will the new program be released and are there any case studies that you can share on the results of this new program?

    Thanks, Bill

    1. Bill this is a book. My training programs are already written and available. Check out and


  20. Superb article as usual Ben! Can't wait till part 3, really need to know how to succeed this year

  21. Tony J says:

    Interesting chapter, looking forward to the next part. The funny thing is I'd question the premise that everyone is training to get faster, I love riding my bike and am guilty of riding a great deal in zone 3. I've found as you've said that as soon as I try something different, I get injured. The problem then is I get withdrawal symptoms because I can't ride. Catch 22. Riding is my Ritalin as they say. 5000 miles last year injury free, tried a 5 sec sprint for the first time in ages the other day and tweaked my knee, d'oh! What to do? I'd rather just be able to ride regularly as I enjoy it than "improve". I don't do events as they are always at weekends and i cant justify the time away from my young family. Trouble is I acknowledge all those junk miles, enjoyable as they are, might not be doing my long term health much good. How to accept this and ride enough for health and well being but not too much?

    1. Start easy Tony. If you want to use the polarized model described in this article and you have a 2 hour ride planned, try this on: ride 80% of your miles very easy aerobic and 20% of them super high intensity.

      i.e. 80% of 120 minutes is 96 minutes. That leaves 24 minutes of intensity. So, for example, you could squeeze 12 two minute hard intervals spaced throughout your long ride, with full recovery after each so you don't have a high risk of injury…

  22. Christian says:

    Maffetone and Ingham's study both say that all of our training should be low intensity, so why use 20% (or any fraction thereof) to high intensity training? Even the other studies you cited with different intensities didn't have have group with 100% in the low intensity zone(?). Maybe they, too, would've confirmed Maffetone's theory?

    1. I recommend you read this: – namely: "Numerous descriptive studies of the training characteristics of nationally or internationally competitive endurance athletes training 10 to 13 times per week seem to converge on a typical intensity distribution in which about 80% of training sessions are performed at low intensity (2 mM blood lactate), with about 20% dominated by periods of high-intensity work, such as interval training at approx. 90% VO2max."

      1. Christian says:

        I hear what you're saying, Ben! Collectively the 80-20 split is the most used approach amongst the elite, thus hypothesizing that such a split is the cause of their success. Sort of like evolution within endurance training community. But, even the review you cite above doesn't answer my question (well, at least the abstract doesn't): what would the results say if different splits (e.g. 80-20 or 70-30) were compared with a 100% low intensity training group? As was the case in the above mentioned Ingham study. Why not have a 100% low intensity group as a control group.

        One could argue that a 100% low intensity training was the holy grail of endurance training, then all these elite athletes would move towards such training, right? But I wonder if psychological factors play a role here. I mean, putting in the time with low intensity stuff without the possibility to give it all you've got sounds pretty boring. And counter-intuitive, I'd like to add. Can't remember any Ironman finishing a competition at a pace "…where you cant still have conversation while you're running". :-)

        1. Several such studies have been done in cyclists with "No HIT" control groups Christian. Results showed that HIT outperforms no HIT every time…

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