brianappleby

I'm trying to get around taking a test.

If I can do a 30 min TT at 375w average, is there a way to calculate/guess what my LT is?

Thanks,

B.

Snicklefritz

I asked a similar question a while ago and got some answers from the resident TT guru DrWJO. He's very knowledgeable on how to interpret power files, particularly for TT work. I'll have to dig up the notes I got from him since I don't recall what the exact percentage was. In the meantime however, I seem to recall Hunter Allen saying in one of his clinics that for FTP he will look at someone's 20 minute power and then assume that is 93-95% of FTP. I'm not sure what you'd do for 30 minutes, but fiddle with the percentage and that will give you a rough idea. If you use CP numbers on the other hand, I think CP30 is supposed to be 103-105% of FTP.

375W is a nice number. Would you be willing to give up maybe 50W? I could use a few...

NomadVW 

If you have a 30 minute mean max, take your 5 minute or 10 minute mean max and toss them in the Monod's chart and you'll have a pretty good estimate of FTP.

We could all take this moment to remember that unless you're doing 40km/1 hr TT's on a regular basis, FTP's accuracy really only alters your training zones and the size of the penis you show up with to the regular sizing up contests. The more important of these is your set up of training zones and if your training zones are working for you - then go with it.

The other important thing is to "determine" your FTP in the same manner each time you have the desire to adjust it so that your workout's intensity will load your TSS and affect your performance management chart the same way.

bbp

Using Hunter Allens method you're around 356 W. How much do you weigh?

NomadVW 

Problem is, a 30 min TT isn't Hunter Allen's method. His method involves some all out efforts prior to the 20 minute effort to work off some of the anaerobic component.

If you're warming up and TTing for 30 minutes - you're best off using Monod's. If I use Monod's CP method, I can take my mean max avg power for 5 and 10 minutes and mean max normalized for 20 and 30 minutes and I get a number that is within 3-5 watts of what my tested FTP is.

brianappleby

Where is monod's chart? I weigh 179 lbs. (proud to have made it under 180...)

NomadVW 

https://velo-fit.com/articles/monod.xls

stea1thviper

all i know is that if my 30min TT averaged 375 watts, my watts/kg would be the same as many of the pros in this year's tdf based on their power data

brianappleby

well either I'm fat or i'm lying.

orcanova

I think LT (Lactate Threshold) is better measured by HR (Heart Rate), not W (Watts). If you run or bike for 30 minutes at the maximum pace you can sustain steadily for that duration...you will find yourself hovering a few beats below your LT, or AT as it is called. They are both the same thing, because they both happen at the same precise point. One moniker refers to lactic acid, the other to anaerobic. It also used to be called the DP, (Deflection Point), although I have not seen that term used for a while. When you go anaerobic, your lactate production increases significantly to the point that your body cannot handle it, and thus your legs become lactic acid recepticles, also known as LAB's, ( Lactic Acid Buckets).

You stay there for a brief period of time and you are T, (Toast). That is most commonly referred to as your TP, or (Toast Point). If you watched today's TT in the TdF and saw some guys, like Levi, whose legs looked like lead weights on the small climb, they went over their LT and stayed there, thus hitting their toast points. Other guys who were dancing on that climb , like Contador, didn't hit it. Sometimes you hit it, sometimes you don't. Sometimes it has to do with your training, other times it has more to do with vodoo curses that other people throw on you when they see that your mojo bag is empty (your MT, or your"Mojo Threshold.")...it's all measurable with HRM's and PM's...main thing is, stay away from your TP at all costs.

Got it...?


BTW, if you do hit your MT (Mojo Threshold) before you hit your LT (Lactate Threshold), and then decide, over a night of "BB"ing, (Bourbon Bashing ) to apply a testosterone patch to your "NS," (Nut Sack), then the rest of the world will pretty much think you are a "DB," (****** Bag).

And if you don't agree with me, you can effin' "BM" ...!!!

asgelle

You can think what you want, but lactate threshold (however it is precisely defined) as used by the exercise physiology community is a power, pace (mainly for running), or VO2 which elicits a particular concentration of lactate in the blood. It is not a heart rate. Heart rate is a response to workload, and so it is possible to roughly assign a heart rate that corresponds to the intensity of LT.

orcanova

Actually, you can think what you want, but lactate threshold became a term in exercise physiology when the science of training by heart rate developed in Europe in the 1980's, well before people were training by power output numbers. (Conconi was the pioneer, and ironically, Dr. Ferarra was a student of his.) I never said LT was a heart rate, I said it was a precise point, which corresponds with a very specific heart rate where the body's lactic acid production increases dramatically.

It has absolutely nothing to do with power output, or watts. It is tethered to that specific point. If you graph effort on the horizontal axis (pace/rpm/watts, whichever) and HR on the vertical axis, you will see a direct linear correlation (a diagonal line) where the points on the graph are plotted. That is until the heart rate reaches the point of the athletes aerobic threshold. It is also referred to as lactate threshold. It is also called a deflection point because at that point the diagonal line on the graph deflects, and the linear correlation is broken. (This was called a Conconi test, but it also involved drawing blood at specific stages of the test, which is no longer necessary.)

Your power output changes significantly with training, but your LT (and the corresponding HR) does so very little, nor does your VO2 Max change dramatically. They are largely controlled by your genetics, and to a much smaller degree training and age. Your VO2 max is higher than your AT, they are not the same thing, and LT has very little to do with VO2 max, but everything to do with a specific heart rate at which your body changes the way it produces energy. When it no longer uses oxygen in the process, you are in an anaerobic state, and the production of lactic acid increases dramatically.

The idea that you can measure your LT by something so vague and non-constant as power output is just silly. Its actually backwards. You know your LT based on HR, then you can look at your resulting power output. You train to increase that power output at that heart rate.

You are completely wrong when you say LT "is a power or pace or VO2." Sorry, but you shouldn't call somebody out on something you know nothing of.

asgelle

Maybe I know nothing about this, but I think this guy might know a little. https://www.cyclingforums.com/archive...hp/t-5678.html

orcanova

A guy pimping his book on power training is trying to discredit training by heart rate...? Heart rate training has a lot more science and application behind it over the years than power training. I'm not saying power training isn't effective, I think from all I've read it is extremely effective training for cycling, but you called me out with a condascending post...and then said some things that are completely wrong...

asgelle

Similarly, Andy has this to say https://groups.google.com/group/watta...f5528d7d16471a

"The scenario you put forth is widely accepted among the scientific
community...although it is really as much a matter of the scope of
improvement in various parameters as it is their speed of improvement.
That is, there is more room for improvement in lactate threshold (in
terms of power and absolute VO2) than there is in VO2max, since lactate
threshold can and often does (if the training is sufficiently
intense/protracted) get closer to VO2max with training. Even so, there
are case reports in the literature of individuals with limited prior
athletic background taking up endurance training and experiencing very
large (up to 50-60%) increases in VO2max over a several year period. [emphasis added]
Thus, one cannot conclude that just because you've been training X
number of months, no further increase in VO2max is possible.

orcanova

LT is associated with heart rate...plain and simple...

asgelle

That charge (though totally without merit) might at least have some appearance of credibility except for the fact that the post was written four years ago, long before the book was published.

Snicklefritz

Whew! you could cut through the testosterone in here with a knife. Calm down men!! Everyone in here has some good points.

Orcanova's point about "The idea that you can measure your LT by something so vague and non-constant as power output is just silly."...my comments:

I'm not sure what you meant by this. Power output isn't vague. I think that's the point that a lot of people have made in numerous posts both in this thread and elsewhere. A watt is a watt is a watt. HR can fluctuate for a lot of different reasons. Can I measure LT through power numbers? It depends on how you look at it. If we're going to get down to semantics, then technically no. If you want to measure LT then do a blood lactate test and figure out mmol lactate as a function of some protocol on an ergometer. Is that something that people are going to do in the field? no. By looking at your power output as a function of mmol lactate you can make some relationship between the two. So power at LT is then a manifestation of where that transition point is.

i think it's important to look at all the variables. I use a powertap and generally go by wattages for intervals but I also do look at the heart rate after the fact. I can make better judgements about fatigue level, hydration status etc. by looking at all the parameters, not just heart rate or power alone.

Squint

The problem with HR is that it's a dependent variable. A change in lactate concentration is the result of workload, often expressed as watts or %VO2max. The rate of work being done by the body also elicits changes in heart rate. The association is that increasing the workload leads to an increase in heartrate. Lactate concentration is therefore also a dependent variable.

If you were to draw a simple flow chart, you could put "Workload" on the left and HR and lactate concentration on the right with one arrow leading from "Workload" to HR and another from "Workload" to lactate. To infer changes from HR to lactate, you have to go from HR back to workload and from workload to lactate.

Remember, HR is not work (just look at the units of measure of HR), it is only related to it and the relationship is such that it would be prudent not to use a dependent variable to define the independent variable.

stea1thviper

lol yes one of those two

asgelle

And what is an ergometer other than a device for controling the power output of the subject?

Snicklefritz

What a couple of people are pointing out (in response to orca) is that if you want to get really technical then no you don't measure LT by looking at power. You measure LT by looking at blood lactate...but power can be used as a manifestation of what's going on with lactate content. Ergometer isn't the key point in some of the earlier comments

asgelle

As Squint pointed out above, lactate concentration is the dependent and intensity (power) is the independent variable. Power is not a manifestation of blood lactate concentration; it is the cause. There are many responses to exercise intensity including blood lactate concentration and heart rate, but there are many more such as core and skin temperature, respiration rate, and perspiration rate. Any of these can be used to study the body's response to exercise, but only lactate concentration can be used to determine lactate threshold (by definition). The independent variable can also be expressed in different ways: power, pace, VO2; but unlike the dependent variables mentioned above, these are not distinct. They are just different ways of expressing the same intensity.

Lactate threshold is defined as the point at which the independent variable (intensity, power) elicits a predetermined value of the dependent variable. So while saying I'm using 4 mmol/l as my value for the dependent variable at LT defines how I'm setting LT, that number has no value alone in evaluating an individual as everyone will have LT at 4 mmol/l. What is important is the value of the independent variable which causes that value, say 300 W.

pcates

where's danno when you need him

Squint

Ah, yes, Mr. Pedal in Circles or You'll Stretch Your Crankarms.