FasCat Coaching did a lot of lactate testing in the past, and Frank Overton came to the pragmatic conclusion that power is good enough for most people. I’ve been doing that for 2 years and happy with results, so I’m not scheduling any lactate tests with a local coach that has been doing lactate and gas exchange testing for 10+ years.
However I’d love to see my lactate curves at various times throughout the season, hence my interest in other estimates like INSCYD, HRV, and decoupling. But more and more it seems like yet another set of estimates that may or may not correlate with LT1. So I’ve kept it simple and use power zones, and both my coach and I manipulate those a bit.
You can see lactate remains very stable through the first six stages (100-200 watts). That is an indication energy is being supplied predominantly by the aerobic break down of fat.
We start to see lactate elevate just above baseline between stage 6 and 7 (200 to 220 watts). Although that is not what we label “lactate threshold,” it is a threshold of sorts. We call it the Aerobic Threshold or LT1, and first jump of lactate from baseline is the indicates a greater contribution of energy from the breakdown of carbohydrate.
So yeah, aerobic threshold or LT1 is a marker where aerobic metabolism of carbohydrates starts to increase.
we should probably think of lt2 as a range as well.
Yes absolutely, with MLSS at the bottom and CP at the top.
The range >MLSS and <CP is interesting as you get a mix of heavy domain and severe domain behaviours, for example lactate will not reach a steady state, however VO2 kinetics will, and there’s no depletion of intramuscular energy stores (that comprise the W’).
it is a metric to monitor the impact of traininig. Especially for long distance endurance sports it is favourable to have high fat ox at higher intensities, e.g. to move it right. Especially for carb thirsty athletes (see the interview with Bu on Blu’s training, their approach must have been successful in this regard … or this is at least what they claim)
I just did a 60min sweetspot (90% FTP) session pinned at 227W (resistance mode).
60min
Avg Pwr: 227W
Avg BPM: 150BPM
PW:HR : 1.1%
EF: 1.52
I also tracked DFA a1 with fatmaxxer and was mostly between 0.75-0.80. A month ago did a DFA a1 ramp test and runalyzer gave 145BPM/220W as LT1.
So maybe, not that bad test. But an LT1 just under sweetspot. Maybe to high. But my FTP was higher before a covid infection end of 2021 so maybe my upper zones are not as strong as my lower…
After always loving the term MLSS, I’ve grown to prefer Kolie’s definition of FTP: the power above which an athlete’s rate of fatigue greatly increases (or words to that effect). Why? Because it’s functional, it doesn’t require blood/gas/breathing/lab testing, and it’s something we can actually use in training on a day-to-day basis with athletes.
Then you get down below/around LT1/AeT/VT1/whatever, and again, something you can feel… ride by the talk test, or criss-cross it, or throw in a few 10-20 minute intervals above the talk test “threshold”.
It’s honestly getting too complex with too many scientists trying to make too many studies that prove their one particular thing is “optimal” when the reality is there is plenty of “good enough” out there.
As @WindWarrior mentioned with respect to FasCat, power is readily available on your head unit, doesn’t vary all that much day-to-day, and can be used to inform RPE… it’s the practical/functional/pragmatic king of the metrics.
It’s not. Problem Coggan had in the first T&RWAPM book is it got bastardized into “Power you can sustain for about an hour” largely because the rest of the definition you left out says… “for about an hour.”
The mistake was including time at all.
And “quasi”… WTF? Scientists. Kolie’s language is a little bit easier for the layman to understand. You can explain that point to an athlete - “Do you feel like you can hold this for a long time?” “How about now?” “How about now?” and then you hit that point where the burn really hits and you know it.
I’m trying to drive everyone to start discussing the crossover concept, because without that, all of this discussion of low-intensity is redundant, or worse, pointless. It’s all the same stuff. Just do a lot of it. But then, as you say, how to measure improvements? How to know where on PD curve and how much to train? With crossover concept, might NOT BE all the same or redundant (endurance vs. tempo vs. low tempo vs. high tempo)
With all the hours of endurance I’m logging, there is always that uneasy feeling that if I just knew my LT1 then I could further optimize training. Probably because San Millan does it.
Isn’t that why we are all gathered together in this thread, ‘exploring the space’ that is guesstimating LT1 without actually testing lactate?
Couldn’t you have 2 athletes with the same cross over point but have completely different capabilities of processing lactate. So one could be way below LT1 and the other way over it?
