Competitive club runner, I guess this is not elite:
If we use a LT1 similar to the elite’s paper the gap would be even smaller
Not sure W/kg would be better…
you missed the “;” its 150/minweek for the moderately active group!
I’m not elite, not even close, but I “got fast” by consistently doing this on Tuesday (along with more z2 work during the week):
and that particular day I was pushing around .73 IF if I remove the outliers:
Post-ride workout notes: “Waited for the wind to die down - at lunch it was 30mph gusting 40. By the time I left it was 20+mph gusting 30mph. Headed out on my normal route and detoured to a neighborhood due to wind. Treated this one as a recovery climb, worked my full normal cadence from 70-95rpm.”
Hmmm, it was windy so those two extra-curricular bursts of speed must be Strava and me doing the sixty going on sixteen dumb guy making Strava noise:
Yup. Just a big old dude trying to get some while he can!
and that 138bpm… I’m going to share my heart rate voodoo economics:
HR-zone2: 128-142bpm
break into thirds:
128-132 bpm = z2-lower
133-136 bpm = z2-mid
137-142 = z2-upper
and I tend to target z2-upper on these 2 hour rides, which is usually .73 IF and higher.
I have a pile of 6-8 hour rides supporting the idea that I can push low 140bpm on hilly century rides. Not all day - the >8 hour rides I’ve enjoyed and dropped bpm down into 130-136bpm range.
That’s all WindWarrior HR/power voodoo economics, not my coach, and without benefit of lactate or gas exchange testing.
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LOL
This math/engineering nerd has complete and utter disregard for precision on writing out those SWAGgy thirds 
Go in a lab and get tested, or SWAG ballpark and go with it! Get in touch with how you feel.
Experiment. In 2020 and part of 2021 I went conservative during the self-coached using FasCat off-the-shelf plans and started capping endurance rides by HR. I’d push power and cap it by HR in either z2-lower (128-132bpm) or z2-mid border (134-136bpm). After hiring a coach he told me to push on power. At first I was a bit stubborn, as he came in about midway thru that 12 month experiment. Results were ok but disappointed that experiment didn’t go as well as planned. Sometime Spring 2021 and into 2022 I’ve pushed those 75-125 TSS endurance rides up into z2-upper (both HR and power), and ‘magic’ happened. My coach was right. For me, averaging 8 hours/week, it seems that progressing from ~68% ftp (early base) to 75+% ftp works. We don’t test often, so I triangulate that lower aerobic by looking at power:HR and aerobic scores on Garmin.
More endurance, fewer intervals.
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who would have thought
I’ve done a LOT of z2 in the last 12 months in particular, also in the low to mid z2 range. Last 3 months I also added increasing amounts of tempo at 80-82% and low and behold…big increases in 5 and 20 min power.
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Indeed.
Except for the rare gratuitous hard group ride, me too.
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Even though the absolute difference in kmh is the same, the slower speeds represent a larger time delta. Either way, unless you’re plotting the threshold against %vo2max then we’re not comparing apples to apples.
What i noticed, is even in the elite runners selected for the breaking 2 project, only a small subset of them had the close thresholds as described. The aggregate of their data was 9% difference, but the sd was high. Most cyclists have a need for a steeper pd curve and thus have a more noticable difference in their thresholds. Which does sort of support the mader and heck model that says the two of them are related to your fractional utilization of vo2 at lactate threshold. (At least the way i understand the model)
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Noticed this one today, thought it was relevant to this discussion. I have been using kubios to calculate dfa but i get below .75 even in the 120’s when lactate shows that happening about 10 beats higher.
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I agree with him. Moreover, the metric is extremely sensitive to the variability of the effort, the connection of the HRM, the position of the strap….way too finicky to be useful.
Saw that on Twitter this morning. Good thing I didn’t invest much time chasing another indirect marker.
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Not wrong necessarily, just using Skiba’s exercise physiology jargon (some of it dated, some of it just his preference) while the rest of us were in the context of LT1, LT2, FTP, etc. Different models.
I don’t have the book yet but when it arrives I imagine I’ll read passages like this one that Skiba posted on ST forum years ago (including here for those who don’t want to buy the book):
He wrote:
I think the problem here is that we have a whole lot of terminology that people in sport use somewhat recklessly and inaccurately. Let me try to help clear things up a little bit. (Besides all the athletes I coach / sports medicine I do, I work in one of the best laboratories in the world with respect to this stuff). In short, there are really two “thresholds”, if you like.
At the low end, we have Lactate Threshold or LT . This is simply the point where lactate rises by 1 mmol / L over exercise baseline. In other words, if you are zipping along at 1.5 mmol / L, and you speed up enough that you reach 2.5 mmol / L, you have crossed LT. This is actually a lot easier to do than most athletes realize. You could ride around at / about LT for a couple hours without much of a problem.
In the middle, we find OBLA, or Onset of Blood Lactate Accumulation , is when you hit 4 mmol / L, irrespective of where your baseline was. This term is not used frequently used anymore, and we should probably avoid it .
At the high end, there is the MLSS, or Maximal Lactate Steady State . This is simply the highest level of exercise we can maintain while maintaining a steady concentration of lactate in the blood. Any higher, and we see a progressive increase even if we maintain a constant power. MLSS is intimately related to the concept of Critical Power , and is probably one of the biochemical manifestations of reaching Critical Power (if you are on a bike) / Critical Speed (if you are running or swimming or whatever). The physiological “stuff” going on at this point is probably what results in the “feeling” of “threshold”, and is what is partially responsible for what Andy Coggan calls “FTP”. FTP is probably not reflective of some unique, alternative threshold phenomenon . It is just convenient shorthand , and results from your body “understanding” that if it goes much harder, bad stuff is going to happen (like inexorable fatigue). In other words, FTP that you observe in the field by doing something like a 40KTT is probably pretty close to, but just slightly lower than CP in a well trained athlete.
This begs the question, what is CP and how do you measure it? If you did a bunch of all-out exercise tests…i.e. went as hard as you could for 3 minutes, and then for 5 minutes, and then for 10 minutes, and you graphed them on a piece of paper, you’d get a curve. It would be high on the left, and then slope down to the right. The place where it seems to level off is CP. You can also make the same graph by using joules (this is easy… watts = joules per second), and you get a straight line, and the slope of that line (rise / run) is equal to CP. ( PLEASE NOTE : This is C ritical P ower, the real scientific one, not the bastardization used by many people to refer to the hardest they can go for some period, like “CP30” for "the hardest I can go for 30 minutes).
Basically, it goes like this. As you cross LT, you begin recruiting less efficient muscle fibers, which tend to use more glycogen / carbohydrate and less fat for fuel. The result of this is an increase in lactate in the blood. This is not a problem. The lactate is taken up by other cells / organs and is metabolized. (Lactate is an energy-rich compound, not a waste product. It doesn’t in and of itself cause fatigue ). In triathlon, it is a problem only in the sense that your body glycogen / carbohydrate stores are limited, and that you can “bonk” if you aren’t getting enough carbs in while you race (if the race is long enough). Additionally, we see the emergence of what is called the “slow component” of oxygen use. In other words, let’s say your LT is 170W (not unreasonable for an age-grouper). Below 170W, you are using some constant amount of oxygen. If you made a graph, you’d see your oxygen use rise up as you started, and then become a straight line. Now, if you ride 180W, what you will see is that your oxygen use seems to kind of level off, and then (maybe a minute or two later) there is another “hump”. In other words, it appears as though your body suddenly realizes it needs more oxygen to do the job. However, this second “hump” also levels off , so you again end up with a steady state of oxygen use. It is just that you are using more than you might otherwise have expected.
The key is that so long as you stay below Critical Power , your body is able to maintain a physiological steady state . After several minutes, oxygen use levels off, lactate concentration levels off. In the muscles, the concentration of creatine phosphate (PCr), ATP, inorganic phosphate and hydrogen ion (i.e. pH) stabilizes. Once you go hard enough to cross Critical Power, bad stuff happens. In other words, let’s say your CP is 240W. If you go to 250W and hold it, things get interesting. Even though the work rate is not changing , there is still a progressive increase in the amount of oxygen used, a progressive increase in lactate concentration in the blood, and a progressive decrease in ATP, PCr and pH inside the muscle. It is very cool, because you cat actually watch a lot of this stuff happen with a specialized MRI setup. Eventually, you reach some limiting level of the concentrations of the other stuff, fatigue, and must stop, or at the very least drop to some much easier intensity.
I encourage people to stop thinking in terms of lactate. Everyone does it, because it is so easy to measure. However, it is really just a very indirect market of some much more important / interesting stuff that is going on in the body, most of which is not easy to measure without expensive gear. From the perspective of the average (or even professional) athlete, it is simply important to realize that you don’t want to be crossing CP with any significant frequency or for any significant duration if you are expecting to do your best in a triathlon, particularly a long course triathlon.
@Quaestor
TLDR; His LT is not LT1 in the strict sense, but it is the lower one. Also, this is over a decade old, so his use of historical terminology is understandable if not justified.
Also, if you look at HR at LT and HR at CP, with training you can get those two heart rates to be very close to each other within 5-6% in elites. That is in contrast to looking at power at LT1 and power at FTP/LT2. Those are never going to be within 10% of one another, even for elites. Different methodologies and concepts. Also, HR at LT1 doesn’t move. Power/speed and lactate change with training, but HR remain fairly static. In the LT1/LT2 inflection point way of looking at lactate curves, I would argue the analogous concept is that the curve in highly trained gets really flat. Same idea as “move LT close to CP”, expressed two different (and seemingly contradictory) ways.
(sidenote: if you don’t like reading paragraphs and paragraphs…well, Skiba may not be your guy. I certainly am not your guy) 
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He goes on to define his four zones.
< LT
LT - CP
CP - VO2max
> VO2max
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And also it appears to give better results when cycling (particularly when inside) as opposed to running.
OTOH
Validity of Detrended Fluctuation Analysis of Heart Rate Variability to determine intensity thresholds in professional cyclists. European Journal of Sport Science.
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His new book is really good and relies heavily on math and CP
Looking forward to it. Although I’m the poster child for the common refrain: “biology, the science for scientists that are bad at math”. LOL. So we will see.
Interesting…
Is that really saying that ‘pro cyclists’ are producing 201w at 153bpm for LT1?
Looks odd given 51 yr old Joe Average me produces about 210w at 153w DFAa1 0.75???
Or am I completely missing something here? (Very possible )
Good question. We have to wait until the study is published, it was accepted by the journal, should be out soon.
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I thought the same thing. Could be female cohort.
True - but even the LT2 numbers look really low to me. I’m not entirely sure what female pro’s numbers are like but surely LT2>280w?