Calculating LT1 and LT2 approximately without a blood test?

Tnx for link to the Burnley TTS pod. It was a good listen. Seems like a pragmatic fellow.

I’m going to go stare at my best data sets as he prompted a few thoughts…

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I wish the sports science field would unify around what they call these thresholds. The British way to call them LT and CP throws me every time, especially “Lactate Threshold” for the first threshold.

I personally like Aerobic Threshold. LT1/LT2 is also very clear.

Seiler usually calls it the “first lactate turnpoint”.

I’m ok with FTP, MLSS, or CP.

I’m reading Skiba’s book now. He uses the British language and I’m constantly having to translate. I even think he occasionally writes “lactate threshold” a few times when he means the second threshold.

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Totally agree. I was watching a Youtube video sometime ago and thinking “what is this guy on about?” until it dawned on me that he was actually talking about LT1 and not LT2 when he was referring to the lactate threshold.

I’ve recently seen references to LT1 in WKO5 webinars from Cusick. For you WKO5 users, how is it determined in WKO?

(sorry if this is upthread already…point it out if so and I’ll dig in)

which webinar? I did a quick search of charts and nothing obvious came up, or I chose poor search terms.

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58:05 he gives a teaser, paraphrasing “we are currently doing hundreds of lab tests in Europe, working on new LT1 modeling system, which we hope to release soon, early results promising”

and then he concludes with “I estimate LT1, we’ll get into that later”

Interesting, so far WKO has always stated:

LT1 & LT2 typically track together as metabolic fitness increases / decreases.
The added complexity of maintaining two such marker is not worth the small
amount (if any) additional information it supplies

And they’ve lumped everything <MLSS/LT2 into the stamina metric

Yep, and I couldn’t find my Spock Fascinating meme fast enough. So I’ll just settle for this comment: the world is changing :man_shrugging: I’m cautiously optimistic. I was told it didn’t exist. LOL

It was a year ago.
I got the impression they’ve all but given up on modeling it.

Maybe that’s how they determined it doesn’t exist.

^^^ joke ^^^

Could just be YAGNI.

Early base he looks at classic EF increases and cardiac drift. Then he looks approximate power output at LT1-HR and FTP-HR (red and green at lower right of chart). Its possible to track per workout as in that chart above, but uses too much CPU to track across a season or last 90 days.

Maybe. “Until we can completely validate it we won’t release it”

Sometimes you aren’t happy with a model because it carries too many caveats - it isn’t good for generalized / unsupervised use. So the model may work great for one athlete, but falls down with another. Or only if the athlete is doing a lot of the same training, for example, mostly steady endurance rides. Someone would need to ask on FB group, or email Tim and ask.

I know all that. I watched the video. I’m asking about LT1.

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Reminds me of the BSX sensor. Lt2 could be predicted pretty well, Lt1 not really. They never delivered on the Lt1 promise. And then it died. And I lost my faith in wearables

No Moxy for you then? (rhetorical)

Sorry I haven’t watched those WKO webinars, so I’m putting on my captain obvious hat and regurgitating what Tim said.

Tracking movement of LT1 using soft estimation:

  • “lots of ways to estimate LT1”
  • “track power at HR approximation”
  • “long term trend, a couple of micro-cycles, of that number improving, I feel reasonably confident that we are moving LT1 to the right”
  • “that’s how you use soft data”

Personally, for the last couple years I’ve been tracking trends in power at 140bpm:

  • 19-20 season it was 171W average power
  • 20-21 season it was 180W
  • last 90 days its was 185W
  • last 4 weeks its was 188W
  • last night it was 198W average / 202W normalized for 130 minutes

Here is a snippet of the chart:

image

(max fractional utilization for this season was 87.9% woo hoo!)

And season high modeled and field tested ftp of those seasons has been 265-275 ish. My zone2 HR tops out around 142bpm, and 140bpm is what I can consistently target, week in week out, for second half of the 70-130 minute interval on steady state endurance rides.

In WKO there are aerobic reports, one example is the Aerobic Power Report Cycling tracks power at 150bpm, I’ve modified all of my reports that use 150bpm to use 140bpm which is my proxy for LT1. Because for me, 150bpm is the top of tempo around 88-90% FTP.

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I know. All good.

I was waiting for the “such and such may or may not” list from above. We gotta keep that going.

Also, for what it’s worth, I have found value in combining TIS w/ TSS the last year or little more. Gives context to load. Crude (and unrelated to LT1), but better than nothing.

I’ll try updating that list this week.

Moxy reminds me of those old Commodore Atari times, they really have to work on the product design at this price point.

The only wearable that could get me currently is this breathing rate thing. But this would be a winter toy for the basement

However, somehow I have lost any motivation to spend money on toys. Current situation and so. Even though I am not really affected financially.

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Our formerly local Kona age grouper moved to Kona, and she posted on Strava a couple times this season wearing that $5000 oxygen mask thing. Benefit of her choosing the right coach :joy: