Where do the FTP % of the different training zones come from

Hi everyone, lately I have been wondering where do the % of FTP for the different Training zones come from?

I know Coggan came up with them in his book, but are they backed by data and specific physiological changes at around the transition borders or they are just pure educated guesses to make prescription of intensity easier?

Also why is sweet spot 88 to 94% of ftp? When was it determined or who based on what?

I love this zone system I would just like to really know the motivation and data backing it.

Also do other power zone systems exist? While Coggan zones have monopolised the english speaking amateur scene, are there other systems? What zones do professionals use?

Cheers!

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Backed up by data, the whole TR approach is extremely data-led. Chad devours data and is constantly looking at all the research out there so that we don’t have to, plus they have their own data to analyse - millions of completed TR workouts (and a few incomplete ones) and FTP tests.

Other zone systems definitely exist, a whole plethora of them!

SS is basically trying to get you maximum bang for your buck. I.e. working at a hard enough level to provide a strong training stimulus, but not so hard that you can’t go again the next day. Not all systems have SS on there as a separate zone. Don’t get too hung up on the exact percentages, the whole thing is a power curve, it’s not like you’re using totally different energy systems at 94% to 95%.

Not always that relevant to look at what the pros are using. Firstly they have access to much more sophisticated testing methods than most of us do - e.g. they can directly establish where lactate threshold occurs by taking blood samples during testing, and they can measure VO2 max using a mask, whereas we have to derive (or guesstimate…) those numbers from other data. Secondly they’re doing way more volume than us, like 20+ hours/week. You can’t do 20 hours of sweetspot training a week, you’d burn out, so pro training typically involves a higher percentage of endurance and tempo work than would be optimal for a time-crunched amateur looking to get the most out of, say 6-8 hours/week. Hence the use of SS as giving maximum bang for your buck.

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Thanks a lot for the reply.
I do not doubt TR is data led in terms of training plans, training zone distribution, load increase week over week, etc. but specifically in terms of training zones to me it looks their method is just a transcription of Coggan’s zones.
I am curious about the rationale of the zones, I just do not want to take them for granted…
I get there is recovery zone, endurance all day zone, high endurance pace that you can hold for several hours but is tiring (tempo), intensive endurance you can hold for maybe around an hour (threshold), and from there aerobic super hard efforts (Vo2max) and anerobic effots.
But why are the percentages established as they are, how did Coggan arrive to those?
Also an interesting thing related is: does RPE go hand in hand with % of FTP or higher FTP cyclists can just suffer and hold the power for longer - does 187 watts for a 250 watt FTP cyclist feel the same as 300 watts for a 400 watt FTP cyclist?

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Last question first as it’s the easiest one to answer! The RPE goes hand in hand with the % of FTP. Higher FTP cyclists may have developed a greater ability to endure the suffering, but it still hurts just as much. As Greg Lemond said, it never gets easier, you just go faster.

Since you’ve mentioned Coggan a couple of times, this is quite useful background reading without getting into the weeds too much - https://www.trainingpeaks.com/blog/power-training-levels/
(hope it’s OK to post links to TP).

One key takeaway is that he doesn’t actually have a SS zone on his chart - SS as used by TR is a mix of high tempo and low threshold from the zones he defines here.

Other key takeaway is to look at table 2 which covers off the adaptations at different zones. This reinforces the point I made earlier that the zones all overlap in terms of the training benefit they provide.

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You may find this podcast with Andy Coggan interesting as I did…

One takeaway from it is that the choice of a 7 zone system was arbitrary. One could make a 3 zone system, or a 12 zone system, but I think Coggan settled on 7 zones because he thought it was specific enough without being overly specific.

The other takeaway was that Coggan described sweet spot as a concept. He seemed more interested in the idea of working harder to gain more adaptations, but without overly stressing your body so that you needed awhile to recover. Hunter Allen wanted to put percentages to sweet spot, so they decided upon 84-97%. I’m not sure what the origins are of the more narrow 88-94%.

Anyways, I highly recommend this podcast episode. I learned a lot.

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The podcast @FeltZ4 linked to will likely answer most (if not all) of your questions.

Another one that overlaps with this one a bit but is specifically about zones is:

To more directly answer your question about TR, they are just using the de facto standard zones. There are other systems/zone (generally using HR), but if you are training with power and doing “threshold training”, it is most common to use the Coggan zones.

Another thing to keep in mind is that zones are coaching concepts, not strictly physiology concepts (and when a physiologist does settle on a definition of a zone, there’s a LOT of hand waving and semantic two-stepping…for an example, see above Fast Talk link). This generally comes down to the arbitrary nature of levels of intensity (as has been pointed out) coupled with the need of a coach to communicate with an athlete.

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Coggan’s preferred terminology is “levels”, not zones, a point he often emphasises. But we might as well call them zones, since the rest of the cycling community has adopted and appropriated his system in their own ways.

Levels were motivated by the need for coaches and athletes to communicate about structured power work. Those levels needed to be grounded in physiology, but also make enough sense to allow work to be both prescribed and described. Since part of the motivation was to create a communication tool, simplicity was important. Seven levels was the sweetspot (pun intended) between creating a simple system, and accurately describing the physiological demands of training at certain intensities. There’s a famous chart from Training and Racing With a Power Meter that shows the expected adaptations to performing appropriately designed intervals in each level, which you can find easily online (search something like “Coggan adaptations chart”).

Coggan’s belief was that lactate threshold was the most important “anchor point” for defining training levels, which is why the original model specified levels of intensity as a percentage of FTP.

In recent years, his original seven level model has been replaced by something he calls iLevels, training levels that are individualised to a person’s capabilities. The lowest four levels are, I think, the same, defined relative to your FTP. The higher levels are generated from your power curve, with suggested durations and target power ranges for prescribing workouts. Part of the motivation for this is that suprathreshold capabilities can vary pretty wildly between people, so you’ll likely need a different sprint workout to me, for example.

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Many would disagree, but I’m a fan of not trying to fine-tune and nit pick the power numbers.

There are no magic physiological changes that suddenly happen at 56%, 76%, 91%, and 106% of functional threshold. There are efforts which place more emphasis on some pathways than others, and, short of VLA max testing and lactate profiling on a regular basis, riders are probably best off aiming for the middle of training levels as they seek to stimulate positive adaptations that suit various types of racing efforts.

You need endurance. So ride at a pace you could ride at every day for 3 hours, for a week, and you’ll be ok on that point.

You need stamina. So you do some “sweet spot.”

You need functional threshold. So you do those intervals where you hit a power you can sustain for 2 x 20 or 2 x 30 (not blowing the first one out and dong the next one 10-15w lower).

You need 3-8min speed. So you go as hard as you can repeat for 16 or 20 or 30 minutes of work intervals or whatever.

As I’ve ragged on before, Coggan has said more than once that levels are descriptive, not prescriptive. Set the duration targets and if you use the PM to help you pace them, then let it reveal to you how hard is your “sustain for each interval for the whole set” hard. The adaptations will take care of themselves.

annoying power proverb: “the truth is in the cells, not the numbers”

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Zone based training of one sort or another in endurance sports has been around for well over 100 years.
The revolution in cycling was no the concept of zones. That concept had be around for a long time, first with pace based RPE systems then heart rate based. It was the invention of the power meter and then tying zones to power and coming up with algorithms to use the data to track training response over time that pushed cycling forward and Coggan did a huge part of that work. Despite where cycling training is now, it was IMHO well behind the science curve compared to running and swimming until the early 2000’s.

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The funny thing I found about this episode was when Coggan described how he rides a bike. First, he doesn’t ride a bike. He sometimes rides a trainer for fitness and he only rides at sweetspot. I just found it funny that the godfather of this stuff would ride in such a uni-dimensional way. :slight_smile:

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Yeah, I also read somewhere (but do not remember where) how one season he was just doing 1 hour, 6 days a week @ 90% FTP and how he got the best shape of his live, so was about to start competing again, but then had an accident or something came up (speaking from memory) and could not do it

Was that before or after he did VO2max intervals every other day for 6 months?

:laughing:

Running and swimming had the advantage of controlled environments (the pool and the track), and as a result were training by “power” when they trained by pace.

open water swimming and XC running could look a bit at heart rate, but that, like heart rate in cycling, was an attempt to find an indirect measure for what could be measured directly in the controlled environment.

every day, cyclists owe uli schoberer a debt of gratitude

(we’ll forget about the powertap before there was a powertap mavic max)

back in the 80s Coggan was winning state road race titles in texas, and he was, by his ergometer workouts then, 5.4 w/kg.

Coggan has legit racing and riding cred, trust me.

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This is a hilarious read:

Coggan used to hold a national masters record or two, didn’t he?

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Wow, imagine if he had used polarized training. He might have made it to the pro ranks. :slight_smile:

He did. He tried the Hickson protocol three times a week for a few months leading up to a state TT. 6 x 5min @ VO2 max. Said it made him really good at going really hard for 5 minutes, but made him slower at going really hard for 50 minutes.

Yeah, that’s what I thought. Any idea what his VO2max was?

probably mid-70s.

to get 5 w/kg, a reasonable VO2 would be 70.

using the ACSM formula of watts x .0108 + mass in kg x .007 = L/min@VO2 max

70kg rider, 4.9 L/min would yield about 410w@VO2 max. 85% of that VO2 max, 348w, so close enough to call it 5/kg – and for your FTP to be 85% of VO2, you’d have to be on the high end of amateurs, as most of us are right around 80%. So 5.4 w/kg, that would need a power at VO2 of about 440w, so that 85% FTP would be, say, 370, That’s 75 ml/kg/min.

That’s up there.

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