Mapping 7 Zone to 3 Zone Model Wrt Polarized Training

It was a very steady (VI=1.03, D=2.63%, 3h15m) easy indoor ride on Zwift. I was well-hydrated, rested and cooled.

I think you might be onto something - the transitions on the short workout make it more obvious where a1 was?

Here’s the HR, a1 chart for that ride. I haven’t done the same for the long ride yet.

For contrast, here’s the chart for the 3:15 ride I mentioned above. You can tell it is still below my LT1 given where the DFA a1 is, but that’s about it - even when the inevitable drift sets in and my HR starts to approach (but not pass) my LT1, it’s not obvious. In fact the opposite might be true? DFA a1 seems higher in that last hour than the first?

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Here’s Bruce Rogers’ assessment of the two graphs:

Bruce Rogers on Twitter: “@neptuak @altini_marco The first - great example of finding your threshold circled in green. The second is also a good example of staying below your AT on a long session. I don’t classify large variation in a1 when it’s above .8 as an issue (it’s normal to see). Note the steady a1 despite the HR drift https://t.co/bN4ZVngWIp” / Twitter

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If you ask me, like anything in the HRV world, I would tell this is “open to interpretation”. I can’t understand the bit about heart rate drift but a1 = 0.75 being unchanged. Does that mean you do not cross intensity boundaries in hot weather? Muscle glycogen usage does shift around with heat, so not sure.

Early days, but as it gets adopted, we might see better tools made for it. I can’t see myself riding outside with a 3-lead ecg poking my eyes into an HRV logger.

Frankly, on the “easy” LOW days of Polarized training, you shouldnt have to monitor anything particularly even power. The simple “go by feel” RPE would trump all of this.

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Yup, I was confused by his statement around HR drift and it not impacting DFA a1. Well, i’ll just keep watching its development.

Luckily, this is all just intellectual curiosity for me. As you say, those long slow rides should be done on feel. They should be easy. Your HR should remain steady and ‘low’. That’s how I ride them.

@Clifford_Smith Bit puzzling but more data is necessary to see if this remains the case on long rides.

When heart rate drift happens, R-R time span should decrease. That’s no different than working at a higher intensity, as heart rate would increase in that scenario too. In your graph, I can see a1 increasing and decreasing where Rogers indicated a straight line with the green ink. As to why there’s no net downward trend on DFA a1, I do not know.

Here’s a plot of real heart rate drift and marathon run speed in a certain study on marathon pacing. The speed was very steady, until runner hit the wall. The sharp loss in speed corresponded to the drift and change in “fractal scaling of the heart rate”. If we hooked up this HRV logger to this chap, I wonder what we’d find. If DFA a1 stayed steady despite the drift, the utility of the tool would mostly be lost.

Who knows! It doesn’t make sense. This science stuff is beyond me … I’m just going to ride my bike! :wink:

Hi Ron,

Interesting reading.
I am also interested in the spreadsheets.
Are you willing to share them with me?
Thanks upfront!

Gr Johan B

I’d love to see something like this:
Z0, <50% FTP
Z1, 50-75%
Z2, 76% to 100%
Z3, 100%+
or wherever you think VT1/VT2 land

hi,

I’ve read a very interesting article about LT1, the base for an appropriate polarized training approach.

80% of HRmax will be higher than HR at LT1 in untrained subjects, but will be lower in the advanced. In addition, HR at LT1 corresponded tot 77 and 86% of HRmax in the least and the best trained, respectively. In an often-cited study, Achten et al (2002) found that fat oxidation was maximal (FATmax) between 68 and 79% of HRmax in 18 moderately trained male cyclists. This publication alone suggests that staying below 80% of HRmax will do for BE training.

The present data also show that both lactate thresholds come closer to each other with increasing training status: LT1 and LT2 were only 29 Watt (9%) or 10 bpm separated from each other in the fittest subjects. Hence, the difference between producing no lactate at all and a lot of lactate is very small in well-trained men, and this is an additional reason to be careful with training at intensities close to LT1, apart from the fact that systematic training at such relatively high workloads (LT1 = 252 Watt when maximal power = 314 Watt) costs a lot of energy.

De https://www.backtobasicsinsports.com/en/blogitem/111

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In the 3-zone default map, S1 is at 75% HRmax.

Atleast for me, it looks very close to where I’d be with RPE ~ 3.5. If you asked me, I like where the %HRmax stands for VT1 limit in the 3-zone model and think there’s a decent margin there, unlike with the 7-zone model, Zone 2 upper limit is a few beats higher than where I’d prefer it personally and maybe eats into that margin a bit. Perhaps the default 7 zone upper cutoff for Zone 2 upper correlates more closely to a lab derived LTP1. What do you think?

Yes, with training a right-shift of LT1/LT2 happens. That’s been known for sometime now. I’m not sure it delta would be 10bpm for me; in my fittest state I think it was on the order of 15-17 beats. Issue is that because the lactate tests are specific to the mode of exercise, your biking and running LT deltas might be different. Thats the annoying part about lactate tests - having to test in different modes if you do more than 1 sport.

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This should be a great piece for a foundational basis of this post. From Mark Burnley.

Bottomline is - zones should map to physiological domains.

Thresholds and intensity domains

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I wonder where the iicu’s definition of the upper HR limit of zone 2 (89% of LTHR) comes from?
I find this is too high. I have a HRpeak of 178bpm and my LT1 (so the upper Z2 limit of a 7-zone model) is 128bpm. I got this from a blood lactate test in a lab and the DFA alpha1 estimation of LT1 coincided surprisingly well. If I ride up to 143bpm, I would be well above LT1.

What do you think about the 89% of LTHR for the upper Z2 limit?

HR zones exist since quite a while and there are different opinions. Intervals has presets from well known sources. You can check the sources from your HR settings.

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If you have done actual lab testing then you should adjust the zones according and not use the presets. They are only guides. I am hoping to get some of this DFA a1 stuff going so I can get a better idea of my own zones.

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Zones are based on averages of the results from the testing of the masses; the simple bell curve. Anyone that is an outlier wouldn’t need it from using the defaults. For example, Joe Friel’s test protocol and zones are found here:

You will notice that it’s a range, not an absolute value. If today you are struggling to hold the pace at 89% of LTHR, then you can lower the intensity and ride/run at 87% or 85% or even 81% of LTHR. You will still get the benefit of the session, versus trying to push through at the upper limit of the zone. Likewise if you’re feeling stronger than normal you would then push closer to the upper limit.

In terms of having been tested (blood lactate), it is always better to set the zones, as David has said, to be custom.

If you want to convert 7 zones displayed as a 3 zone model, TrainingPeaks make provision for that in their settings under LTHR, you can select 80/20 cycling and/or running. Simply replicate this in this app in the custom settings:

Thanks for the information, guys! I was rather refering to the set preset zones, but I was not aware of this Preset menu, which makes it all clear and transparent.
I have the feeling though, that Joe Friels LT1 estimation is way too high. A friend of mine also confirmed this in his case. But sure, I cannot prove that this is statistically representative for the big mass - it is just a feeling.
Did some of you check that with your personal LT1, in case you did conduct an DFA-alpha1 or a blood lactate test?

How about the Threshold, base, polarized classification, are these affected by the definitions of the zones? I assume these are independent from the zones and solely based on the boundaries that were mentioned by @Mike_Lauder above?

I find ep. 54 of the FastTalkLabs podcoast super clear and informative about the polarized training approach:

Stephen states the LT1 and LT2 are roughly around 70%± and 90%± , respectively, and this is quite well in line with my estimations. How about adding Stephen’s 3-zone model to the preset selection?

I am aware that these are all ranges and there is still a significant benefit if I am in that specific zone. Nevertheless, I find the lower LT1 threshold very critical if I would like to follow the polarized training approach - better stay well below that threshold than touching/exceeding it. Stephen has emphasized this multiple times in the FastTalkLab episodes.

Gerald, that 80/20 usually discarts Tempo and Super Treshold work. In terms of Long HIIT like 4 min, based by the HR, I can’t reach the values that 80/20 says

Hmm, I think you need to re-listen to that one. The image below is right out of Dr Seiler’s own documentation.

Also note that this is for Eliete and Well-Trained Athletes! As Dr San-Millán and Alan Couzens recently pointed out, it’s all dependant on the state of a person’s metabolic health.

Nor should you. 80/20 is based on sessions per year not time in zone. When using TIZ it’s more like <10% HIT for elite athletes with a very well established base over many years.

80/20 as described by Dr Seiler doesn’t discard Tempo, it’s just used appropriately and counts as time above LT1.

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