lactate threshold - Triathlon Week

12-15-2004, 08:21 AM

I have a friend who is getting his lactate threshold measured and I am
curious as to how useful this is for training. What does this
measurement tell you and how can you use it in your training? In
anyone's opinion, is it worth paying $100 for?

Thanks!

12-15-2004, 12:29 PM

kskurski wrote in message
<1103127680.771494.44510@z14g2000cwz.googlegroups. com>...
>I have a friend who is getting his lactate threshold measured and I am
>curious as to how useful this is for training. What does this
>measurement tell you and how can you use it in your training? In
>anyone's opinion, is it worth paying $100 for?
>
>Thanks!

Though I was once a believer in measuring and using LT in training, I now
believe that while it's still an important concept, it cannot be reliably
measured in ways that are reproducible and representative. There appear to
be too many other factors which influence one's lactate levels on any given
day for measurement to be useful.

For direct measurement:
[Only registered and activated users can see links. ]
For heart-rate deflection measurement:
[Only registered and activated users can see links. ]

Both methods appear to be flawed.

-Tony

12-15-2004, 02:12 PM

A lactate profile test can be quite valuable in determining appropriate
training intensities and also in evaluating changes in fitness level over
time. There are several factors that you must consider when contemplating
having a test:

1. Who is doing the test. A trained exercise physiologist would be who you
are looking for. Beware of individuals who do not have an appropriate
background who claim to be performing physiology tests. Most appropriate
individuals will have at least a bachelors degree in a related field
(exercise physiology, sport science, kinesiology, applied physiology,
integrative physiology, biology, etc.)...and many will have a master's
degree or higher.
2. What equipment is used. A true lactate threshold test involves measuring
blood parameters. Only a trained person in the appropriate place with the
appropriate equipment should be doing this kind of test. There are a number
of small hand-held devices that measure blood lactate concentration. I have
not seen any solid evidence that these units are both valid and reliable. I
do know that there are research papers that do find some of the devices to
be reasonable, but I have not used nor seen any of them used to be
appropriate. Some may disagree with me here. Blood lactate concentrations
are being measured in millimoles of lactate per liter of blood - from only a
drop or two of blood. The sensitivity of the instrumentation to effectively
measure this must be excellent - not just OK. The USOC (and most other
quality sport science labs like ours) uses YSI lactate analyzers. In our
lab, we are also able to measure blood glucose concentration as well as
blood lactate concentration using our analyzer. We have had coaches in the
area bring in their hand-held devices and test the same blood sample that we
use on our YSI analyzer. There have been many instances where the hand-held
devices gave measurements different by more than 2-3 mmol/L...which is
completely unacceptable.
3. Protocol used. There are a lot of different protocols out there, but to
get a steady-state blood lactate concentration, each stage should be 3-4
minutes long. In our lab, we like to see 2-4 stages where blood lactate
concentrations are stable (baselines), 2-3 stages of slight increases in
lactate concentration (< 1 mmol/L increases), and then 2-3 stages of
significant (> 1.0 mmol/L) increases. Usually, our tests last 6-9 stages (4
minutes/stage) and heart rate and perceived effort are also evaluated in
addition to blood lactate concentration at the end of each stage.
Speed/power should be increased at consistent intervals for each stage of
the test after the warm-up.
4 Sport tested. You should be tested in a mode of exercise in which you are
training/competing. Ideally for a triathlete, you would test swimming,
cycling, and running. I've done lactate profile tests swimming (using
progressively faster 200m repeats), but don't really recommend it. We do a
lot of tests on individuals both running and cycling (different days), and
there can be different results from one sport to another. I have evaluated
professional triathletes that have different heart rate at lactate threshold
by up to 20 beats/minute. This is the extreme, and most will find their LT
HR to vary by about 5-10 beats/minute from cycling (lower) to running
(higher). The most important part of the LT test is not at what HR it
occurs...but how much work (how fast) you are going at that point! (See
next).
5.Interpretation of results. This is probably the hardest part of the whole
test...not for the athlete, but for the physiologist. There are a number of
different methods of identifying the lactate threshold point. It is
important to what what method the lab that you are using has for determining
the LT. Some methods are better than others...and I tend find that the
stage where a 1.0 mmol/L increase in blood lactate occurs is often close to
a "performance threshold" for endurance athletes. By that, I mean that
well-trained endurance athletes are able to maintain the speed/power
associated with this point for 1+ hours. For example, a well-trained
runner/triathlete will often be able to run about 1/2 marathon at what I
call the LT pace (pace associated with 1.0mmol/L increase in lactate)...or
be able to hold the LT power +0-10% for a 40 K TT. The HR will usually be
somewhat higher in a competitive situation vs. the lab (due to adrenaline,
cardiac drift, etc.) and I give athletes recommendations how to use the
information. I also believe that assigning appropriate training intensities
based on the lactate profile curve is also superior to any other method.
Several research papers show that devising training itensity based on
lactate profile tests and the lactate threshold are superior to any HR%
based training recommendations. I have tested hundreds (thousand+?) of
athletes, and know that the % HR formulas work in some cases...but are
terrible in many situations as well. We associate appropriate paces/power
outputs along with the heart rate ranges for individuals tested at our
facility, and don't even care about % HR. The test results effectively give
the athlete an objective evaluation of their current level of
fitness/performance capability, and also specific information to use in
training to help improve! Over time, if an individual comes back in for a
test, we are able to overlay the two tests and to compare their results.
This can be quite motivating for subjects, and provides objective
information to the coach and athlete regarding the progress of the athlete.
Another subject, which would require at least as long of an answer about, is
VO2 Max testing. While VO2 max is nice, it doesn't help one devise training
information as well as a lactate threshold/lactate profile test.
Sorry about the long-winded response...but I do a lot of these tests,
and know that there is a lot of mis-information out there. Best of luck,
Neal

Neal Henderson, MS CSCS
Coordinator of Sport Science
Boulder Center for Sports Medicine
phone: (303) 544-5700
web: [Only registered and activated users can see links. ]
email: nhenderson at bch dot org

"kskurski" <[Only registered and activated users can see links. ]> wrote in message
news:1103127680.771494.44510@z14g2000cwz.googlegro ups.com...
>I have a friend who is getting his lactate threshold measured and I am
> curious as to how useful this is for training. What does this
> measurement tell you and how can you use it in your training? In
> anyone's opinion, is it worth paying $100 for?
>
> Thanks!
>

12-16-2004, 11:10 AM

Neal does an excellent job. The other thing I would add is that I question
the usefulness of "one off testing". If you are going to do this, plan to
have it done 3 to 4 times per year to mark your progress and adjust the
training. It is free and can tell one just as much.

As Neal points out, the most critical part is the interpretation (which is
why I think "amateurs" are better off using a fixed blood lactate level like
4.0) and the application.

That said, I think using benchmark workouts and race times is a good way of
assessing changes and altering training intensities. On a bike, a
powermeter is just as good at giving one a "functional threshold" (I can
see Andy Coggan smiling if he is reading this).

"Neal Henderson" <[Only registered and activated users can see links. ]> wrote in message
news:[Only registered and activated users can see links. ]...
>A lactate profile test can be quite valuable in determining appropriate
>training intensities and also in evaluating changes in fitness level over
>time. There are several factors that you must consider when contemplating
>having a test:
>
> 1. Who is doing the test. A trained exercise physiologist would be who
> you are looking for. Beware of individuals who do not have an appropriate
> background who claim to be performing physiology tests. Most appropriate
> individuals will have at least a bachelors degree in a related field
> (exercise physiology, sport science, kinesiology, applied physiology,
> integrative physiology, biology, etc.)...and many will have a master's
> degree or higher.
> 2. What equipment is used. A true lactate threshold test involves
> measuring blood parameters. Only a trained person in the appropriate
> place with the appropriate equipment should be doing this kind of test.
> There are a number of small hand-held devices that measure blood lactate
> concentration. I have not seen any solid evidence that these units are
> both valid and reliable. I do know that there are research papers that do
> find some of the devices to be reasonable, but I have not used nor seen
> any of them used to be appropriate. Some may disagree with me here.
> Blood lactate concentrations are being measured in millimoles of lactate
> per liter of blood - from only a drop or two of blood. The sensitivity of
> the instrumentation to effectively measure this must be excellent - not
> just OK. The USOC (and most other quality sport science labs like ours)
> uses YSI lactate analyzers. In our lab, we are also able to measure blood
> glucose concentration as well as blood lactate concentration using our
> analyzer. We have had coaches in the area bring in their hand-held
> devices and test the same blood sample that we use on our YSI analyzer.
> There have been many instances where the hand-held devices gave
> measurements different by more than 2-3 mmol/L...which is completely
> unacceptable.
> 3. Protocol used. There are a lot of different protocols out there, but
> to get a steady-state blood lactate concentration, each stage should be
> 3-4 minutes long. In our lab, we like to see 2-4 stages where blood
> lactate concentrations are stable (baselines), 2-3 stages of slight
> increases in lactate concentration (< 1 mmol/L increases), and then 2-3
> stages of significant (> 1.0 mmol/L) increases. Usually, our tests last
> 6-9 stages (4 minutes/stage) and heart rate and perceived effort are also
> evaluated in addition to blood lactate concentration at the end of each
> stage. Speed/power should be increased at consistent intervals for each
> stage of the test after the warm-up.
> 4 Sport tested. You should be tested in a mode of exercise in which you
> are training/competing. Ideally for a triathlete, you would test
> swimming, cycling, and running. I've done lactate profile tests swimming
> (using progressively faster 200m repeats), but don't really recommend it.
> We do a lot of tests on individuals both running and cycling (different
> days), and there can be different results from one sport to another. I
> have evaluated professional triathletes that have different heart rate at
> lactate threshold by up to 20 beats/minute. This is the extreme, and most
> will find their LT HR to vary by about 5-10 beats/minute from cycling
> (lower) to running (higher). The most important part of the LT test is
> not at what HR it occurs...but how much work (how fast) you are going at
> that point! (See next).
> 5.Interpretation of results. This is probably the hardest part of the
> whole test...not for the athlete, but for the physiologist. There are a
> number of different methods of identifying the lactate threshold point.
> It is important to what what method the lab that you are using has for
> determining the LT. Some methods are better than others...and I tend find
> that the stage where a 1.0 mmol/L increase in blood lactate occurs is
> often close to a "performance threshold" for endurance athletes. By that,
> I mean that well-trained endurance athletes are able to maintain the
> speed/power associated with this point for 1+ hours. For example, a
> well-trained runner/triathlete will often be able to run about 1/2
> marathon at what I call the LT pace (pace associated with 1.0mmol/L
> increase in lactate)...or be able to hold the LT power +0-10% for a 40 K
> TT. The HR will usually be somewhat higher in a competitive situation vs.
> the lab (due to adrenaline, cardiac drift, etc.) and I give athletes
> recommendations how to use the information. I also believe that assigning
> appropriate training intensities based on the lactate profile curve is
> also superior to any other method. Several research papers show that
> devising training itensity based on lactate profile tests and the lactate
> threshold are superior to any HR% based training recommendations. I have
> tested hundreds (thousand+?) of athletes, and know that the % HR formulas
> work in some cases...but are terrible in many situations as well. We
> associate appropriate paces/power outputs along with the heart rate ranges
> for individuals tested at our facility, and don't even care about % HR.
> The test results effectively give the athlete an objective evaluation of
> their current level of fitness/performance capability, and also specific
> information to use in training to help improve! Over time, if an
> individual comes back in for a test, we are able to overlay the two tests
> and to compare their results. This can be quite motivating for subjects,
> and provides objective information to the coach and athlete regarding the
> progress of the athlete. Another subject, which would require at least as
> long of an answer about, is VO2 Max testing. While VO2 max is nice, it
> doesn't help one devise training information as well as a lactate
> threshold/lactate profile test.
> Sorry about the long-winded response...but I do a lot of these tests,
> and know that there is a lot of mis-information out there. Best of luck,
> Neal
>
> Neal Henderson, MS CSCS
> Coordinator of Sport Science
> Boulder Center for Sports Medicine
> phone: (303) 544-5700
> web: [Only registered and activated users can see links. ]
> email: nhenderson at bch dot org
>
> "kskurski" <[Only registered and activated users can see links. ]> wrote in message
> news:1103127680.771494.44510@z14g2000cwz.googlegro ups.com...
>>I have a friend who is getting his lactate threshold measured and I am
>> curious as to how useful this is for training. What does this
>> measurement tell you and how can you use it in your training? In
>> anyone's opinion, is it worth paying $100 for?
>>
>> Thanks!
>>
>
>