Fast Talk Podcast, Ep. 72: Do we need training zones?

After listening to most of that podcast I’m still non the wiser. What is the difference between a Level and a Zone? For some reason it seemed to be important.

  • Quite simply, semantics. It is a name/designation of a particular area or range of interest. There is no real difference what you call it.
  • The areas of interest are defined by metrics like Power, Heart Rate, VO2 Max or other ones.
  • The real important thing is to pick a training model or system (with the related area names), and then use that as the common language for any people that you plan to discuss your training (like a coach or other rider).
  • You need to make sure you are on the same page when you discuss the related training and efforts.

I agree with @mcneese.chad. It’s mostly semantics. I’ve listened (and read) other statements by Coggan related to this naming and it seems to come down to the fact that he wants to stress that they are not discrete areas with hard dividing lines. Fair enough. The body doesn’t work that way. And it’s a good message, especially for folks who have a tendency to quibble (with themselves or others) over percentage points along the PD curve. And yes, as he points out, you have to draw the line somewhere.

Unfortunately, both the word “level” and the word “zone” (by definition) indicate discrete divisions. So it really just adds to the confusion. It’s too late to make the language precise at this point so we’re stuck with it.


I can’t help but think Trevor Connor is becoming more conflicted. He was very pro Seiler and Polarised but Coggan (who can be an arse on various forums) seemed to want to shoot that down a little. I do also think Seiler sounds more and more tired on each podcast which is a shame as he was very infectious on the first 2 velonews podcasts, both of which I have listened to about 10 times!

I think there seems to be a lot of coaches / physiologists coming to the fore with very strong opinions and it’s starting to feel like you need to choose one way, go with it and see if it works, otherwise…



I think a bulk of the good discussion begins around 16 minutes into the cast. It gives the background on the “why” of setting levels (from Dr. Coggan).

  • It’s largely about giving definition of areas for the purpose of setting training efforts/intensities. The precise name is not important, but the area of interest is what matters so the athlete can perform at the desired effort/intensity, in hopes of driving desired adaptation.

More good stuff at 22:00 with intent of prescribing workouts by coaches to athletes. It is an effort to define the goal or range for a desired intensity to perform. Re-emphasized at 23:55 with Trevor’s example, but properly addressed with the limitation of specific needs and different values or names. The comment (from Stephen) is golden and perfectly addresses the entire topic at 25:00, with backup by Dr. Coggan right after that.

I am listening to the cast for the second time. I find the primary question as something that was not deserving of a full cast in a way. It is nearly arbitrary what they call call the points or ranges of interest. What matters is using the same terms and understanding the link between the term and the related metric of concern, so the training can be performed and evaluated.

As usual, I find Trevor’s repeated examples of “guys say they are riding in Zone X…” tiresome. That and the new “I compared umpteen heart rate zone systems and they are all different…” annoying as well. (around 1:04:00 for the start of this mess)

  • He doesn’t bother to give any background on what precise HR method is related to any system, or how that range for that one was demonstrated.
  • It’s about as silly as saying “I measured this block and it was 2, 17, and 3.4…” without giving any idea what measurement method (actual measurement system like Inch, Millimeter, etc.) was used.
  • If he was really trying to educate the listener, he needed to list each system and how they derived their ranges (HRMax, Lactate Threshold HR, or whatever as the base). Just saying “Zone 2 in this system is X, Zone 2 in that system is Y…” is worthless. It only adds confusion with not context or attempt to resolve it.
  • Overall, more frustration about how Trevor approaches these discussions.
  • I got a great giggle from him getting corrected early in the cast when he said the one system was based on “Heart Rate Variability” and Stephen (I think) immediately corrected him. The term Heart Rate Variability is used in a very different context, and considering what Trevor as covered on the cast, he should know well.
  • Maybe it was a realistic slip that we all make, but considering how much emphasis Trevor places on people misusing terms, I thought it was super ironic :stuck_out_tongue:

I think the important distinction is the connotation that a zone implies distinct separation whereas a level is simply an area/position within a greater landscape. Which is important to us because the adaptions that occur overlap between the levels

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was that before or after he mentioned all the pro athletes he coached? drink!

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LOL, I don’t think he said “pro” at any point, but he did mention his athletes and what he does with them a time or two.

One thing that Coggan, Seiler and most coaches all seem to agree on is that amateurs are too focused on hitting specific power numbers in workouts and seeing short term FTP improvement. This seems to enter every conversation on training with power.

Zones, levels, whatever are tied to physiology and without some realistic self assessment and physical awareness a lot of athletes aren’t getting the adaptations they are looking for. This is especially true in the longer run. Chasing power numbers isn’t training.


The levels don’t avoid the separation at all. In fact, the separation points in the Levels are firmly defined in the 7-Level Coggan model:

Even the newer iLevels have distinct points to separate each one:

Your picture covers the adaptations that can be derived from time spent in the various levels. It correctly demonstrates that various adaptations can be gained by work in various Levels. There is not a simple 1:1 relationship about training time to adaptations gained.

The important thing mentioned in the cast and here, is that these hard lines are necessary to make some prescriptive work practical, but the reality is more nuanced. Our bodies transitions are a more gradual fade of the rainbow rather than hard color transitions. So the precise value used in our metrics is likely less important than the general location we aim for in the training.

Did we listen to the same podcast? They aren’t my levels/zones but Coggan explains why he doesn’t like the term zones, so while its a semantic argument I can see his point, and as you point out the number of zones/levels is a practical one, not a physiological one. Connotations in language are important

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Agreed people are too focused on hitting an exact number, and the times you hear people say they failed a workout because they had to turn down intensity 5% is astounding. The physiological benefits gained/lossed from one session that is 10W high/low are within the noise of our ability to measure.


We did indeed listen to the same one. And we are getting to many of the same points. The only issue I have is thinking that using the term “levels” somehow avoids the hard segregation issues from the term “zones”. The names are essentially arbitrary, but there is a line drawn in each system, no matter the name given to the range of interest.

And the separation between each one in any system must be assigned to a particular numeric value, thereby making a “separation line”. That is unavoidable unless they try to make deliberately overlapping values, and that would likely only serve to add confusion. Coggan knows there is a blend, but he still had to set hard numbers for the split between each one of his 7 (and now 9) Level systems, to make them practical and useful.

So, hard lines are necessary from a prescriptive standpoint, but so is the recognition that the reality is more fuzzy than the implied precision of each system. And yes, realizing that we can be a bit over or under on any given workout or day is super important. The implied precision of the tools and training models is not the reality that we have at hand, and that is very worth consideration.


I was annoyed that Trevor kept talking about how he hated the term “zone” and how “levels” were somehow better. As Chad said, they are exactly the same- different names for non-overlapping segments of the range of values that a physical parameter can take. All the talk about the semantics of the name partially obscured the major point- the important thing is understanding the point of each workout and how hard/ long you are targeting going.


Yup, they touch on it at several points, specifically 1:21:00, which is great. And they cover it pretty well, but I agree that the semantics muddy the water and lead to a loss of focus on the more important picture (continuum of the spectrum).

The difference is that the previous 7 zone model uses % FTP (power) to define all training levels.

The new iLevel uses:

  • FTP to set training levels for aerobic endurance, tempo, sweet spot, and threshold
  • individual physiology to set training levels above threshold

In Dr Coggan’s Individualized Training: The What, Why, and How Of the New WKO4 iLevels article he gives the example of two world champions, both have similar power above 10 minutes. However below 10 minutes there is a huge difference, where the sprinter can produce 150% ftp for 4-minutes, while the time trial specialist can only do that for 1-minute.

A few more details from the article:

Based on the logic behind the original approach, levels 1-4 remain anchored to FTP, with the addition of a new level 4a (SweetSpot) at 88-94 percent of FTP to satisfy the requests of numerous coaches who have found value in prescribing workouts at this intensity.

However, at higher intensities, four levels (instead of three) have been defined, with the boundaries between them determined based on … the individual’s unique physiology.

The whole point is:

the determination of highly-individualized training levels (iLevels) for describing and prescribing training.

for example my iLevel (from WKO4) for VO2max intervals recommends a low target of 112% 1:1 or 1:2 work/rest ratio. And that matches up well with what I’m capable of using as adjusted intensity in TR vo2max workouts. At the moment, I simply can’t repeatably do 120% ftp vo2max intervals above 2-3 minutes.


The issues of individuality above Threshold are very interesting. I think the evidence of that reality is clear in the many VO2 max threads we have seen in past months. There is wide variability in duration, rest, and repeat-ability of these and higher efforts.

The higher iLevels aim to target these differences and find the more appropriate prescriptive range for each person, vs the more simplistic models that are purely power based across the full range. It’s an interesting option to dig into and learn more about, if those efforts are part of your training and racing world.

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Colby brings the most rational explanation in all their pods he is on.

At one point he got on why he doesn’t like zones and (over simplistic) he doesn’t want you to ride at what your threshold was when you tested, but what it is that day. Go out and ride on rpe and time was the gist.

That was the highlight of the pod for me


Allen, Coggan, Seiler, Weber and Pierce are all on the same page that training is a continuum; levels/zones/izones are more to define how to communicate what it is we are trying to do; the word “Threshold” as in LTHR is from running, 40 years old and based on an arbitrary blood lactate mmol amount that has little if nothing to do with cycling; most amateurs are missing the forest through the trees.

Weber thinks zones/levels based from a % of FTP is problematic because peoples energy expenditure (carb consumption) is very different. Z2 for 1 hour is very different than Z2 for 5 hours or Z2 for 5 hours four days in a row. Coggan hit on this as well but used the words “muscular metabolic fitness” or glycogen utilization. So “FTP” and below is ruled by this energy expenditure/glycogen consumption and is a reason people do long rides…ie long rides improve this.

Seiler thinks zones should be based on physiology. 3 zone model is good for amateurs because they are “out of control” and can not contain how hard they go. Amateurs train well on hard days but, too hard on easy days. 3 zone model is sort of like a green, yellow, red model to keep it simple.

On point Pierce made I thought interesting was that while doing VO2max type work it’s important to feel (RPE) the effort even though the wattage may be low and it’s possible more adaptation is being done. I found this interesting as in one of the books Allen and Coggan wrote they talk about when to give up on an interval if you can’t maintain a certain power…


Did not listen to the podcast. Won’t listen to it. I find zones and percentages of an arbitrary metric irrelevant. I base all my training on absolute wattage and time@wattage from races. I see the appeal for mass marketed training plans, though.

However, I always liked this overlapping system:

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