Pls, up to?
tks
If you’re only interested in AeT, 90% should be enough. Only one deflection point would be found. If you want both AeT and AT, I guess 130% should be more then enough to get both deflection points.
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tks,
had no idea this could “estimate” AT also.
But I think that above 100% would be hard with 6m intervals.
Any tips?
Regards,
If you want to find both AeT and AT, go to failure as you do with a ramp test.
You don’t have to come back down with this method. And it’s not a1 that defines the thresholds, it’s the breathing frequency deflection points who define the thresholds and then those translate into a a1, power value and HR value to define them.
The research on this shows that breathing frequency tracks almost identical as lactate.
Read up before blindly using something.
I have.
But each one has “his own protocol”…
And it has been suggested 6m intervals with 10% increments.
Nonetheless I’m most interested in alternatives of AeT other than lactate.
If you wanna comment and/or help great but your last comment is totally unnecessary.
The most accurate way of defining both thresholds (apart from an expensive met-cart test) is lactate measurement and, importantly, not using fixed levels of lactate but detecting deflection points in the lactate curve during a slow ramp protocol. The first deflection point from a stable lactate level to a slowly rising lactate level is the AeT. When the slope of the rising lactate level increases, there’s a second deflection point, defining the AT.
Early stage research now might show that breathing frequency is highly correlated to lactate, and there is maybe a good chance that the deflection points can be evaluated from breathing frequency. If this proves solid, we have a way of more accurately measuring both thresholds without having to rely on lactate measuring devices.
A reliable way to measure breathing frequency is an absolute necessity. And until now, you needed a respiration measuring device to do it accurately. That’s not a big advantage compared to direct lactate. Garmin’s Firstbeat algorithm for resp rate (derived from HRV) was found unreliable in several comparing studies over already a number of years. But the guys from AlphaHRV seem to have found a more reliable algorithm that is very close to the Movesense device.
That’s where it stands as of today.
An oversimplified view of what the data will show is this:
Where section 1 is the part below AeT. Lactate and apparently resp rate is as good as stable even with rising power in this low intensity section.
In section 2 lactate rises in a linear fashion with HR/Power. If you would stop raising Power, lactate will stabilize too, maybe even go down slightly. Your body reuses the produced lactate as fuel and is able to keep up.
When you keep increasing intensity, you end up in section 3 where your body can no longer keep up clearing lactate and it goes through the roof. Your legs explode…
The better your aerobic condition, the more those points shift to the right.
If breathing rate shows a similar behavior, it is a question of developing a software tool that is able to detect the three trendlines and the cross points. This requires highly skilled mathematics and knowledge of exotic filter mechanics to ignore outliers and artefacts. Until that tool is available, it makes no sense to discuss protocols.
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That test is wrong, you can’t create a cool down, if you want AeT do up to 90%, what is the problem you are going to find that you need a software that sees that trend change as accurately as possible, that is exactly what we are creating.
Indeed, the Firstbeat algorithm has little validity in the measurements, thanks to the collaboration of Bruce Rogers, we have been adjusting the algorithm, we have to think that we are fighting against the low processing capacity of the Garmin equipment, even so we have achieved something that can be worthwhile. We are currently developing an app that detects thresholds, Bruce Rogers commented on the high similarity of the respiratory rate with the behaviour of lactate and we have taken advantage of this to see the same behaviour in the respiratory rate, soon we are going to do massive tests, all with laboratory tests. We are financing all this with our own time and money, so we are going somewhat slowly due to lack of resources.
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I see.
Could you provide one?
Tks
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do you mean you are using the Garmin Dual strap with the Polar H10 sensor?
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Yes. Works like a charm
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We have not tested the Garmin HRM Dual heart rate monitor, but to check if it is valid you only have to enter Garmin Connect and check the Artifacts chart, in wko5 you can also check it by creating a chart and using the formula @artifacts.
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This is a lactate test and it is the same one we are using for the FR, if you do not want to reach 120%, up to 90% would be enough.
-15m 40% power=3s
-6m 50% power=3s
-6m 60% power=3s
-6m 70% power=3s
-6m 80% power=3s
-6m 90% power=3s
-6m 100% power=3s
-6m 110% power=3s
-6m 120% power=3s
Once you finish the test you stop it and record it, do not record cool down.
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Overall, AlphaHRV looks like it is doubling down on breaths.
I’ve noticed that when I have too many artifacts it’s time to wash the band, mostly once a week is enough 
Looking at this graph of DFA a1 to time, would you say I have LT1 around green and LT2 around red? Is that what this is about?
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AlphaHRV does not duplicate respiration rate, as I said the measurements are totally on par with Movesense, it is not worth counting breaths as you do.
As for DFA-alpha-1 I think you do not have the concept very clear, the standard DFA=0.75 is used for first threshold and DFA=0.5 as second threshold, after more than 100 tests we have done, we can say that these values are valid for some and not for others, I do not think that any coach uses 2mmol for first threshold and 4 mmol for second using lactate. Besides in that image you have not calculated the linear regression and eliminated the part at the beginning, besides you have to change some parameters in Runalyze for that regression to work “well”. We stopped testing thresholds with DFA because first the test has to be very well done because it is affected by any movement, depending on the type of test is more reactive and finally with covid those DFA values have changed in many athletes, although there is scientific evidence I guarantee that not all have the thresholds in the “standard” values.
First image without covid and dfa at 0.75
Second image two months after passing covid
Same test, same conditions
Respiratory rate test with alphaHRV
Lactate
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I have done some more testing with the latest version. An important thing to always remember is that the results for a1 and resp rate are always the average of a longer measurement window. For AlphaHRV, the window is 200 beats if I remember correctly. So if you want to verify a stable resp rate by counting your breaths, you should do that for at least 2 min and then compare to the result of the algorithm. It’s not quite instantaneous…
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That’s right, if you want to try with 300 beats contact me privately, depending on the device you can try it, I would give you a code to put in 300.
Not exactly. Data window for a1 and RR are not the same length. For a1, D=200 beats is the default value (configurable for some devices going into developer mode).
For RR calculation, default window is T=60s. You can modify this value, being limited by the beats selected for a1: (T/60)xHR<D
But you are right, a1 and RR are not instantaneous metrics, but average for some period
hi, I tried to perform this test today:
-used 6min protocol
-wahoo ticr with garmin epix watch
-ant+ - alphahrv; bt - garmiin epix been
-wahoo core trainer
i think my results are totally wrong
but my question is,:
-at the beggining there is a countdown from zero to 100%. Have impression it is a base setup. What should i do during this countdown? sit relaxed, ride slowly, or start first step of the protocol?
-what should the artefacts show? what is a correct reading and what reading is wrong? my chart is just empty
-is there any difference between ant+ and bt? Should I use one over another to get better results?
In two days i will try again, so jope this time my reading will be batter 
Maybe it counts breathing in and out separately?