lactate-based versus performance-based training prescription



acoggan

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I came across this old study when looking for something else:

http://www.ncbi.nlm.nih.gov/entrez/...t_uids=7658957&query_hl=4&itool=pubmed_docsum

So much for the notion that lactate data provides a more accurate basis for training prescriptions, eh? :p

(Note that lactate-based training prescriptions weren't any better than performance-based prescriptions despite the fact that the latter were derived from maximal skating velocity, not sustained skating velocity. IOW, the performance-based prescription was analogous to using maximal heart rate or MAP instead of threshold heart rate or functional threshold power.)
 
acoggan said:
I came across this old study when looking for something else:

http://www.ncbi.nlm.nih.gov/entrez/...t_uids=7658957&query_hl=4&itool=pubmed_docsum

So much for the notion that lactate data provides a more accurate basis for training prescriptions, eh? :p

(Note that lactate-based training prescriptions weren't any better than performance-based prescriptions despite the fact that the latter were derived from maximal skating velocity, not sustained skating velocity. IOW, the performance-based prescription was analogous to using maximal heart rate or MAP instead of threshold heart rate or functional threshold power.)

So typical of you. You take a study that measured lactate after work intervals that were short and quite unlike the protocol of a ramp lactate test, that was used to predict performance at lactate steady-state (4mmol/l), and you try to apply the study result/conclusions to completely different protocols and applications, applications that I doubt would ever be used by good coaches/trainers. Maybe your friends at QS and Mapei can explain this to you.
 
WarrenG said:
So typical of you. You take a study that measured lactate after work intervals that were short and quite unlike the protocol of a ramp lactate test, that was used to predict performance at lactate steady-state (4mmol/l), and you try to apply the study result/conclusions to completely different protocols and applications, applications that I doubt would ever be used by good coaches/trainers. Maybe your friends at QS and Mapei can explain this to you.

Uh, Warren? The 60 s interval referred to in the abstract was how quickly following each 2000 m effort they obtained the sample to measure lactate. The bouts themselves were 3-5 min in duration, which as long or longer than almost anyone uses when performing an incremental exercise test on a treadmill, cycle ergometer, etc. (In fact, they are longer than what you've been tested using, aren't they?) These data were then used to predict the velocity at maximal lactate steady state, i.e., then didn't just rely on a fixed blood lactate concentration such as 4 mmol/L (i.e., OBLA). (Which is what Testa uses, right?) This is about as good as it gets when doing lactate testing, and in fact they were able to correctly predict during which trials lactate would/would not be stable over time 81% of the time. The only bad news for proponents of lactate testing (and manufacturers of the necessary equipment) is that a much simpler performance-based approach worked just as well.

"The best predictor of performance is performance itself" - A. Coggan, ca. 1980.
 
acoggan said:
Uh, Warren? The 60 s interval referred to in the abstract was how quickly following each 2000 m effort they obtained the sample to measure lactate. The bouts themselves were 3-5 min in duration, which as long or longer than almost anyone uses when performing an incremental exercise test on a treadmill, cycle ergometer, etc. .

The study did one effort for 3-5' and then took one measurement up to 60 seconds later. A usual ramp test will use 3-5' PER STEP in power or running speed, and a normal ramp lactate test will usually include a half dozen steps and measurements along the way to around 4mmol/l, and probably one step beyond that to see how the lactate behaves above 4mmol/l.

The study used their single measurement to predict performance at 4mmol/l. So what? If they had done the test with a more usual protocol for a ramp lactate test they would have measured the power at, or near their performance at 4mmol/l, which of course would have been near 100% accurate, not 81% accurate like in the study.

The other problem with the measurement protocol in the study (or more correctly, your extrapolations about the study results) is they weren't gathering the blood samples on the way to 4mmol/l so they miss out on the information that could be obtained from those intermediate measurements.

acoggan said:
This is about as good as it gets when doing lactate testing, and in fact they were able to correctly predict during which trials lactate would/would not be stable over time 81% of the time. .

See above. You know all of what I've said so I question why you play games about it.
 
I don't see what there is to get.

Two ways of prescribing training intensity.

One based on power that one can sustain for a certain duration based on power one sustain for a certain duration. Training goal to train a little higher each time in the effort to overload and with recovery improve.

The second based on a measure that has a correlation with increased work but is difficult to measure (riders don't like having blood taken), may be different depending on where you take blood from, may not accurately reflect what is happening in the muscle, depends on the equipment used and the skill of the technician in taking samples. Then you get different measures if you vary the number of samples taken (every 1min or every 5 mins etc).

From this you either base a LT on a set mmol of lactate and we know that some people's LT is not exactly 4mmol because studies have shown that some people can sit on 10mmol for over 60min or you pick a point on a graph where you think a lactate turnpoint appears.

From this complicated measure from a test which can be affected greatly by fatigue levels or nutritional status you plot out training zones.

Call me a simple kind of guy but it seems a very complicated way of going about things with many potential problems when it appears far more simple to say that if my 60min power is 207 watts then when doing subsequent 60min efforts I should do them at 212 watts to cause overload and with recovery should see my 60min power increase.

Hamish Ferguson
Cycling Coach
 
WarrenG said:
The study did one effort for 3-5' and then took one measurement up to 60 seconds later. A usual ramp test will use 3-5' PER STEP in power or running speed, and a normal ramp lactate test will usually include a half dozen steps and measurements along the way to around 4mmol/l, and probably one step beyond that to see how the lactate behaves above 4mmol/l.

You need to read the abstract again, Warren. They did five 2000 m efforts, which took from 3-5 min each, with the fastest one being a maximal effort that undoubtly resulted in very high lactate levels. Blood for lactate measurements was obtained during the "off" lap, which took <60 s to complete. IOW, they basically replicated what you might do when testing somebody on a treadmill or cycle ergometer, only did it at the rink instead.

WarrenG said:
The study used their single measurement to predict performance at 4mmol/l.

No, it (they) did not. What they attempted to do was predict whether or not lactate would be constant, rising, or falling during a subsequent training session that entailed skating 5 laps "hot", 1 lap easy, a total of nine times. They were able to do so for 16 out of the 20 subjects, which, when you consider the day-to-day variability in blood lactate levels, the fact that they didn't measure maximal lactate steady state but only predicted it from the initial multi-speed test, etc., is actually pretty good.

WarrenG said:
If they had done the test with a more usual protocol for a ramp lactate test

There's nothing at all about the protocol that would lead to different results than what would be obtained in the laboratory.

WarrenG said:
they would have measured the power at, or near their performance at 4mmol/l, which of course would have been near 100% accurate, not 81% accurate like in the study.

Unlikely, since the power corresponding to maximal lactate steady state can be either below or above (usually above, at least in cyclists) the power corresponding to OBLA (i.e., 4 mmol/L).

WarrenG said:
The other problem with the measurement protocol in the study (or more correctly, your extrapolations about the study results) is they weren't gathering the blood samples on the way to 4mmol/l so they miss out on the information that could be obtained from those intermediate measurements.

You're wrong:

"...speed skaters (N = 20) performed HLa-P consisting of 5 x 2000 m/400 m at incremental velocities ranging from very slow to maximal (time = 3.0-5.0 min). Blood lactate measured during a 60-s interval following each repetition was used to construct HLa-P..."

WarrenG said:
You know all of what I've said so I question why you play games about it.

About all that you've said (written) here seems to prove is that you don't know how to read.
 
acoggan said:
You need to read the abstract again, Warren. They did five 2000 m efforts, which took from 3-5 min each, with the fastest one being a maximal effort that undoubtly resulted in very high lactate levels. Blood for lactate measurements was obtained during the "off" lap, which took <60 s to complete. IOW, they basically replicated what you might do when testing somebody on a treadmill or cycle ergometer, only did it at the rink instead...


Their protocol predicted performance at 4mmol/l or MLSS with only 81% accuracy. A proper lactate test will do that at near 100% accuracy because it's actually seen during the test.
 
fergie said:
I don't see what there is to get.

Two ways of prescribing training intensity.

One based on power that one can sustain for a certain duration based on power one sustain for a certain duration. Training goal to train a little higher each time in the effort to overload and with recovery improve.

The second based on a measure that has a correlation with increased work but is difficult to measure (riders don't like having blood taken), may be different depending on where you take blood from, may not accurately reflect what is happening in the muscle, depends on the equipment used and the skill of the technician in taking samples. Then you get different measures if you vary the number of samples taken (every 1min or every 5 mins etc).

From this you either base a LT on a set mmol of lactate and we know that some people's LT is not exactly 4mmol because studies have shown that some people can sit on 10mmol for over 60min or you pick a point on a graph where you think a lactate turnpoint appears.

From this complicated measure from a test which can be affected greatly by fatigue levels or nutritional status you plot out training zones.

Call me a simple kind of guy but it seems a very complicated way of going about things with many potential problems when it appears far more simple to say that if my 60min power is 207 watts then when doing subsequent 60min efforts I should do them at 212 watts to cause overload and with recovery should see my 60min power increase.

Hamish Ferguson
Cycling Coach

What you describe about training is overly simplistic. The potential problems you mention about the test procedure are not hard to minimize or prevent altogether. You are also ignoring the problems trying to get people to do long time trials-all kinds of factors that will cause variability in those results, eh?

I would not say that lactate tests should replace all TT tests, but a skilled person can learn useful things from the lactate test that would be difficult to learn (or have good confidence in) via a TT test. For example, in a month or so I'll do lots of training around threshold, so before that I'm going in for a lactate test to learn more about exactly where that level is and how I'm producing that power. IOW, we want to know how much the power is, but also look for clues about how best to improve that power output, with consideration for the components that produce the power at threshold.

Maybe you can send your post to someone you know who makes use of lactate tests and see what they say.
 
WarrenG said:
Their protocol predicted performance at 4mmol/l or MLSS with only 81% accuracy. A proper lactate test will do that at near 100% accuracy because it's actually seen during the test.

Better read the abstract yet again, Warren. They did not attempt to predict performance, but instead whether lactate would be rising, steady, or falling during a subsequent essentially unregulated (w/ respect to intensity) training session. That they were able to get it right the majority of the time is actually rather impressive when you consider all the limitations involved with lactate testing. In any case, though, one thing is certain: they wouldn't have done any better using a fixed blood lactate concentration of 4 mmol/L to define "threshold", since the exact lactate concentration at which maximal lactate steady state is found varies between individuals and even between exercise modalities within the same individual.
 
WarrenG said:
Maybe you can send your post to someone you know who makes use of lactate tests and see what they say.

You mean somebody like Carl Foster or Jack Daniels? Oh wait...we already know what they'd say. ;)
 
acoggan said:
In any case, though, one thing is certain: they wouldn't have done any better using a fixed blood lactate concentration of 4 mmol/L to define "threshold", since the exact lactate concentration at which maximal lactate steady state is found varies between individuals and even between exercise modalities within the same individual.

All more or less true, which is why I mentioned earlier today about going above 4mmol/l during the lactate test and I also mentioned a test done with power or running speed.
 
WarrenG said:
I also mentioned a test done with power or running speed.

I'm confused*: what good would it do a speed skater to know their OBLA (or MLSS) while cycling or running?

*Not really, it's just a figure of speech.
 
acoggan said:
I'm confused*: what good would it do a speed skater to know their OBLA (or MLSS) while cycling or running?

*Not really, it's just a figure of speech.

...Mentioning the relevance of different sports using different tests, or different modalitites as you mentioned. Rowers and XC skiers get their own tests too.
 
WarrenG said:
...Mentioning the relevance of different sports using different tests, or different modalitites as you mentioned. Rowers and XC skiers get their own tests too.

Oh, I see: the fact that you realize that there's a specificity to lactate responses somehow adds to your credibility in this area. :rolleyes:
 
acoggan said:
So much for the notion that lactate data provides a more accurate basis for training prescriptions, eh? :p
LOL! Are you actually *trolling* for Warren now, Andy? That's priceless! :D
 
WarrenG said:
What you describe about training is overly simplistic. The potential problems you mention about the test procedure are not hard to minimize or prevent altogether. You are also ignoring the problems trying to get people to do long time trials-all kinds of factors that will cause variability in those results, eh?

Simplistic because people get a bit lost when you try and make it too technical.

Well as mentioned in another post you don't even need to do TTs when you use Cycling Peaks as it works out mean maximal power for each duration. If you are training hard it will plot all your training durations out for you quite nicely. May not be bang on but I know that I can at least do that wattage for that duration and the goal of training is to increase either the time I can spend at that wattage or increase the wattage over the duration. Pretty simple really.

What does my power output at 4mmol of lactate tell me? It doesn't tell me how long I can ride at 4mmol for. Then if I can ride for 28min at 4mmol of lactate what does this tell me in regards to my performance on the bike. The answer for both is nothing that can't be determined from power X time in the first place.

I would not say that lactate tests should replace all TT tests, but a skilled person can learn useful things from the lactate test that would be difficult to learn (or have good confidence in) via a TT test. For example, in a month or so I'll do lots of training around threshold, so before that I'm going in for a lactate test to learn more about exactly where that level is and how I'm producing that power. IOW, we want to know how much the power is, but also look for clues about how best to improve that power output, with consideration for the components that produce the power at threshold.

If we say your threshold is 60MP then why not use your best power output over 60min. No blood, no errors in testing, measured from the field not the lab. No saying 4mmol is the threshold or a technician guessing turnpoint.

Maybe you can send your post to someone you know who makes use of lactate tests and see what they say.

I have been doing ramped lactate tests for the last year on several riders and found nothing but terrible inconsistencies in the whole process. The only thing I came away with was the riders max aerobic power. In the future I have to decide whether MAP is best or some form of critical power testing.

Hamish Ferguson
Cycling Coach
 
fergie said:
I have been doing ramped lactate tests for the last year on several riders and found nothing but terrible inconsistencies in the whole process.

Have you tried identifying "threshold" using the Dmax method? That might help you make sense of the data a bit better, since it should help control for, e.g., differences in muscle glycogen stores.
 
Another one of those crazy pro team doctors talking about the value of lactate testing...

http://www.pezcyclingnews.com/?pg=fullstory&id=3789

From the chief team doctor at Saunier-Duval...

“We try to organize training in the most scientific way possible. Lactate is the most important parameter for us. VO2 max. is significant, but it is more an indicator of cardiorespiratory adaptation. At this level, most riders will have developed this to its maximum capacity. Whereas lactate tells us more about what is going on inside the muscle cell, how efficient a rider is and provides a better parameter to prescribe appropriate training.”