RoadBikeReview.com's Forum Archives - Racing


Archive Home >> Racing(1 2 3 )


Lactate threshold testing(10 posts)

Lactate threshold testingChrisA
Apr 10, 2002 11:26 AM
Has anyone had their LT HR tested using the method where your blood is drawn? A health club in my area in conjunction with the local cycling club is making this testing available for $75.00. My questions are is it worth it, how accurate is it, and how exactly was it done? I race in the masters/CAT 4 and Vet expert classes and am training pretty seriously this year.
re: Lactate threshold testingmtber
Apr 10, 2002 12:48 PM
I had LT testing done earlier this year and found it very helpful for setting your training zones, which are better based off of LT than max HR. I had guessed my LT previously based on ~ 1hr sustained efforts aka Friel, but had been about 5 beats to high.

The test will be on some sort of stationary bike that should be properly adjusted for you. It should have 'real' (clipless) pedals, so bring your shoes. The bike is hooked up to a computer which can be programmed to let you pedal at different power levels (in watts). It will let you pedal at whatever cadence you want per wattage level, ie either fast and easy or slow and hard. You should try to use you usual riding cadence. You will be given some time to warm up, then the test starts. The computer will start at a very low power setting, you will ride for 3min, then the tester will prick your finger to get a blood sample and take down your HR and perceived effort (RPE). The power will then be upped and after 3min another sample will be taken, etc. During the 3 min the tester puts your blood sample in a machine that determines the blood lactate level in mmol. The curve of blood lactate (mmol) vs HR is exponential, so your blood lactate will remain low for a while and then sharply increase. The test will continue until one or two power settings past the point of rapid increase. I forget the exact definition, but basically your LT is near the 'elbow' of the curve. It is 100% accurate - there is no guesswork involved - you are looking at actual lactic acid vs HR and power.

$75 is a reasonable price. You should get your LT curve vs HR, power and RPE, your HR and power at LT, and your training zones (both HR and power) for this price.

Good luck.
LT is defined as point where blood lactate = 4mmol (nm)mtber
Apr 10, 2002 12:59 PM
re: Lactate threshold testingJon Billheimer
Apr 10, 2002 2:58 PM
I second mtber's description and recommendation. One thing to be aware of with respect to testing, though. There are 4 or 5 different definitions of lactate threshold, which makes the whole concept rather fuzzy, but still useful. The most often used definition is when your blood sample reveals 4 mmol of lactic acid per litre of blood. Another commonly used definition, which the above poster refers to, is Onset of Blood Lactate Accumulation. This is determined by the deflection point which mtber refers to, and is probably the most useful definition from a training point of view. Another commonly used definition is Maximum Lactate Accumulation Steady State, which is the highest level of blood lactate one can accrue prior to reaching the point of rapid accumulation. This reading is really too low for threshold training purposes.

So check with the testers as to their protocol. But the 75.00, if you're training seriously, is well worth it.
Blood test vs. road testKerry
Apr 10, 2002 4:53 PM
The blood test method (LT = 4.0) typically gives a much lower HR than the standard "HR when riding an 8-10 mile time trial flat out." The lower number isn't really much good for training, because all of the advice you will get will be based on the "real world" number you get from the TT test. The reason the TT test is considered more relevant is that it obviously is the HR you can sustain. The blood test is much more arbitrary, as apparently most people can exercise for a long time with higher than 4.0 blood level. That being the case, the blood test has less relation to actual training unless you get a revised set of recommendations based on this blood level.
Blood test vs. road testJon Billheimer
Apr 10, 2002 5:19 PM
Good point. Some athletes have been able to sustain as much as 16 mmol blood lactate before exhibiting a deflection point. The 4 mmol standard has been adopted since it represents a number characteristic of perhaps the majority of tested subjects. OBLA is perhaps the most useful. However the TT standard is important, since increases in lactate threshold are heavily dependent upon production of a protein, MCT-1, which acts as a lactate transporter into the cell where lactic acid can be converted to pyruvate and used as oxidative cell fuel. Work well over LT, as in a time trial, stimulates production of MCT-1 and LT is raised as a result of the body's enhanced ability to clear lactic acid. There are two sides to the lactate threshold equation: the cells' oxidative ability and the body's clearance ability. Once base training is completed, the best way to influence LT is to increase one's clearance rate.
Blood test vs. road testpeloton
Apr 10, 2002 10:00 PM
I think that it would also depend on the type of racing that one would be taking part in. The blood test is a good point to start to determine training zones, and so is the road test. Studies done with trained cyclists have shown that it is not uncommon for a cyclist to be able to operate over OBLA for up to one hour in a time trial. A short 7-10 mile TT done in twenty minutes can be done at an even higher intensity than that. The figure of 4mmol is a good place to start, and one that many in the exercise physiology community will say is good for all, but it is probably dependent on the individual. Your mitochondrial density, muscle fiber composition, amounts of aerobic enzymes, specifity of training, and other factors will effect where your OBLA is going to make you fail.

What I would do is to use the lactate testing as a place to start, and combine that knowledge with what you find in the road TT test. You may find that you can adjust the findings of both for yourself and the events you are getting ready for.

One thing that you may want to think about when you get the test done is to make sure the bike you are on matches up with how your bike is set up very well. Changes in saddle height, set-back of the saddle, handlebar height, and what not can all make a difference in what muscles are used. The muscles that you get used to using in your bike position are trained specifically, and will produce less lactate. Changing your position, even a subtle change, can make a difference in what muscles get activated through your pedal stroke. Using lesser trained muscles due to a change in position on the bike can lead to results that suggest a higher production of lactate than what you would actually get on your own bike. Take your measurements and try to get things as close as possible, or else your results may be a little off.
As an examplejim hubbard
Apr 10, 2002 10:16 PM
Having had testing done, I have an average blood lactate of 9.55 mmol.l-1 for an indoor 40k tt.
Just do itLeGrimper
Apr 11, 2002 12:56 AM
First off, loads of good advice posted. There is a wealth of knowledge here.

Do the test. Don't worry about what Cat you are or if its worth you doing it. This is a fast track way of getting better, less hit and miss.

As already said, use that as a starting point and go from there. $75.00 is nothing compared to the supplements you buy, race wheels, this years jersey etc.

For me the best thing about having these figures, lactate vs power vs HR is that I can chart progress and work on weak points as they become apparent. This is despite the conflict of 4 units per etc.

A graph of lactate accumulation will show the deflection and your lactate at every point until you blow and top out your HR. You can work out a lot of things from seeing it on paper.

I'd be very interested in your final stats especially against where you thought you were.

Finally , enjoy the test and ingnore the pain!! :)

LeGrimp
re: Lactate threshold testingTroyboy
Apr 11, 2002 7:12 AM
Well, if you're going to get it done, there are other factors you might want to know. Firstly, they will likely draw your blood from a easy to get to vein. This is less accurate than the preferred method of getting into an artery close to your wrist. (Supply vs. return). This method is quite painful. Next, if you're going to do that, you might as well get a VO2 Max test, stress test, power test and lung capacity test done as well. While $75 might sound good, I got all those aforementioned tests done for free at the UCLA Medical Center Exercise Physiology Research Lab. Just $75 for an LT might sound good now, however, if you've got to go to several different places, and pay $75-$100 for each, you may end up paying more for the whole deal.

Note: My doctor said that after getting all the other tests done, it's quite easy to get very close to your LT using the collected data. This makes getting the actual LT done by artery virtually unnecessary.