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Functional Power and Lactic Threshold
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BeachboyWI
Oct 16, 09 6:29
Post #1 of 14 (1149 views)
So in preparation for some off season training I did an FTP test yesterday.

The protocol I tend to use is the spinnerval video...so you warm up for about 10 min which include some moderate efforts. Then a 3 min all out effort, and then a few 1 minute all out efforts followed by some cool down. Then the 20 minute test. Over the 20 minute set I averaged 305 watts and my average HR was 155.

If I take 5% off of the watts I'm at 290 as my FPT. (I think, feel free to correct that if I am thinking incorrectly) My main question is about Lactic Threshold. Does this test give an indicator of that threshold? Is it 155, or do I take 5% off that? Or is it something else?

About a year ago I went in to get my LT tested and was told it was 142. That's why I am asking as a jump of 13 beats seems a bit high as I've read this number isn't as trainable as once thought. (perhaps that is incorrect).

Any clarification would be great.

Thanks
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Re: Functional Power and Lactic Threshold [JReed] [ In reply to ]
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desert dude
Oct 16, 09 8:11
Post #2 of 14 (1111 views)
So you set your wattage FTP and now you want to know what your LTHR is?

A quick search using the search function would have yielded the info from just last week.

http://forum.slowtwitch.com/..._latest_reply;so=ASC
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Re: Functional Power and Lactic Threshold [JReed] [ In reply to ]
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Andrew Coggan
Oct 16, 09 8:26
Post #3 of 14 (1097 views)
In Reply To:
So in preparation for some off season training I did an FTP test yesterday.

The protocol I tend to use is the spinnerval video...so you warm up for about 10 min which include some moderate efforts. Then a 3 min all out effort, and then a few 1 minute all out efforts followed by some cool down. Then the 20 minute test. Over the 20 minute set I averaged 305 watts and my average HR was 155.

If I take 5% off of the watts I'm at 290 as my FPT. (I think, feel free to correct that if I am thinking incorrectly) My main question is about Lactic Threshold. Does this test give an indicator of that threshold? Is it 155, or do I take 5% off that? Or is it something else?

About a year ago I went in to get my LT tested and was told it was 142. That's why I am asking as a jump of 13 beats seems a bit high as I've read this number isn't as trainable as once thought. (perhaps that is incorrect).

Any clarification would be great.

Thanks

1. Functional threshold power is the highest power you can sustain for ~1 h, not 20 min. You can guesstimate your functional threshold power by taking 5% off of your 20 min power, but IMHO the accuracy of this approach isn't high enough to justify using it (since when using a powermeter "training is testing and testing is training", I see no point in performing a formal test unless it is reasonably accurate).

2. While it is possible to speak of "heart rate (or power) at LT", it is incorrect to state that "my LT is XXX beats/min". LT is an exercise intensity, and as such is properly expressed in terms of power, pace, or absolute or relative VO2.

3. Heart rate can be quite variable from one occasion to another, even at constant exercise intensity.

4. There are multiple quantitative definitions of LT.

Bottom line? You did two different tests using (apparently) two different methodologies, such that I don't think you can compare the results.
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Re: Functional Power and Lactic Threshold [Andrew Coggan] [ In reply to ]
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BeachboyWI
Oct 16, 09 9:13
Post #4 of 14 (1044 views)
In Reply To:
In Reply To:
So in preparation for some off season training I did an FTP test yesterday.

The protocol I tend to use is the spinnerval video...so you warm up for about 10 min which include some moderate efforts. Then a 3 min all out effort, and then a few 1 minute all out efforts followed by some cool down. Then the 20 minute test. Over the 20 minute set I averaged 305 watts and my average HR was 155.

If I take 5% off of the watts I'm at 290 as my FPT. (I think, feel free to correct that if I am thinking incorrectly) My main question is about Lactic Threshold. Does this test give an indicator of that threshold? Is it 155, or do I take 5% off that? Or is it something else?

About a year ago I went in to get my LT tested and was told it was 142. That's why I am asking as a jump of 13 beats seems a bit high as I've read this number isn't as trainable as once thought. (perhaps that is incorrect).

Any clarification would be great.

Thanks

1. Functional threshold power is the highest power you can sustain for ~1 h, not 20 min. You can guesstimate your functional threshold power by taking 5% off of your 20 min power, but IMHO the accuracy of this approach isn't high enough to justify using it (since when using a powermeter "training is testing and testing is training", I see no point in performing a formal test unless it is reasonably accurate).

2. While it is possible to speak of "heart rate (or power) at LT", it is incorrect to state that "my LT is XXX beats/min". LT is an exercise intensity, and as such is properly expressed in terms of power, pace, or absolute or relative VO2.

3. Heart rate can be quite variable from one occasion to another, even at constant exercise intensity.

4. There are multiple quantitative definitions of LT.

Bottom line? You did two different tests using (apparently) two different methodologies, such that I don't think you can compare the results.

I assume you prefer the 2x20 minute test for FPT?

I agree and know that HR is variable...but don't you think LT is valuable info at all?
If your pushing a low wattage but your HR is above LT, you know something's up right?

So doing an FPT test doesn't even give an indicator of LT HR?
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Re: Functional Power and Lactic Threshold [JReed] [ In reply to ]
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Flanagan
Oct 16, 09 9:20
Post #5 of 14 (1034 views)
This is not tongue in cheek. 2x20 is just another gimmick. Start doing longer threshold intervals in training, and you will very quickly develop a good idea of your FTP. If you really want to know what it is, then do a 60 minute max effort (best average) interval, or better yet do a 40K TT. If you have trouble mustering the courage to go to the brink for an hour, then do 45 minutes or so. Take a few percentage off, and you will be darn close.
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Re: Functional Power and Lactic Threshold [Andrew Coggan] [ In reply to ]
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Andrew V
Oct 16, 09 9:38
Post #6 of 14 (1009 views)
In Reply To:
1. Functional threshold power is the highest power you can sustain for ~1 h, not 20 min. You can guesstimate your functional threshold power by taking 5% off of your 20 min power, but IMHO the accuracy of this approach isn't high enough to justify using it (since when using a powermeter "training is testing and testing is training", I see no point in performing a formal test unless it is reasonably accurate).

I'm curious, on a similar note. If one does a legitimate 60 minute FTP test, then not long after (several days) does a 20 minute test, they can easily derive a 'conversion factor' between their CP20 and CP60 (FTP). In your opinion, how reliable are future 20 minute tests, using that same conversion?
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Re: Functional Power and Lactic Threshold [JReed] [ In reply to ]
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JustCurious
Oct 16, 09 9:50
Post #7 of 14 (993 views)
In Reply To:
I agree and know that HR is variable...but don't you think LT is valuable info at all?
If your pushing a low wattage but your HR is above LT, you know something's up right?

So doing an FPT test doesn't even give an indicator of LT HR?


I don't think you get it. HR and LT have nothing to do with each other. All HR does is imprecisely correlate with exercise intensity.
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Re: Functional Power and Lactic Threshold [JReed] [ In reply to ]
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Andrew Coggan
Oct 16, 09 9:57
Post #8 of 14 (979 views)
In Reply To:
I assume you prefer the 2x20 minute test for FPT?

No.

In Reply To:
I agree and know that HR is variable...but don't you think LT is valuable info at all?

Not in the present context. You're comparing an indirect indicator of the exercise intensity (i.e., heart rate) measured on one occasion under one set of conditions to that measured on another occasion under a different set of conditions and asking "have I changed?". That is simply not a question that can be answered based on the data presented.
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Re: Functional Power and Lactic Threshold [Andrew V] [ In reply to ]
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Andrew Coggan
Oct 16, 09 9:59
Post #9 of 14 (972 views)
In Reply To:
If one does a legitimate 60 minute FTP test, then not long after (several days) does a 20 minute test, they can easily derive a 'conversion factor' between their CP20 and CP60 (FTP). In your opinion, how reliable are future 20 minute tests, using that same conversion?

As long as your training and fitness doesn't change dramatically, then such a ratio probably wouldn't change much either. Again, though, I don't see much point in doing any formal testing unless you can really nail down the answer quite accurately and precisely.
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Re: Functional Power and Lactic Threshold [Andrew Coggan] [ In reply to ]
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newbz
Oct 16, 09 10:08
Post #10 of 14 (956 views)
just an off-shoot of this, and something i was wondering.

say you do a 20 min test, is there anything wrong with basing training around this number, and using a % of this, vs a % of FTP?

the two reasons i ask are:

1- in rowing, we trained by power a good chunk of the time, and based all of out other workouts off of either a 5k or 2k test (sort of like 20 min and 60 min in cycling). would this same approach work assuming you knew what you were trying to target

2- personally i dont have anywhere near me to easily do a 60 min test, and no trainer at the moment.

i could be wildly off base, but just wondering outloud.

thanks
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Re: Functional Power and Lactic Threshold [Andrew Coggan] [ In reply to ]
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Andrew V
Oct 16, 09 10:23
Post #11 of 14 (942 views)
In Reply To:
As long as your training and fitness doesn't change dramatically, then such a ratio probably wouldn't change much either. Again, though, I don't see much point in doing any formal testing unless you can really nail down the answer quite accurately and precisely.

I find it to be a seasonal issue. It's easy in the winter to hop on the trainer for 60 minutes, and pound out a solid test. In the summer, it's too hot to do a workout of that intensity on a trainer, so training is done outside. I find it nearly impossible to do a reliable 40k test outside of a race, either from traffic conditions, weather, or any other number of factors. A 20 minute hard ride to correct for the baseline, however, is far easier to get it. That and a TT or two get you through the hot months, and once temperatures are back under 50 in the morning, you can get on the trainer in the garage and do all of your idealized workouts in a temperature your body can handle.
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Re: Functional Power and Lactic Threshold [newbz] [ In reply to ]
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lakerfan
Oct 16, 09 11:43
Post #12 of 14 (907 views)
In Reply To:
just an off-shoot of this, and something i was wondering.

say you do a 20 min test, is there anything wrong with basing training around this number, and using a % of this, vs a % of FTP?

the two reasons i ask are:

1- in rowing, we trained by power a good chunk of the time, and based all of out other workouts off of either a 5k or 2k test (sort of like 20 min and 60 min in cycling). would this same approach work assuming you knew what you were trying to target

2- personally i dont have anywhere near me to easily do a 60 min test, and no trainer at the moment.

i could be wildly off base, but just wondering outloud.

thanks

I'm obviously not going to speak for AC but for the life of me I can't imagine why it would make a single bit of difference. The goal is to build training stress progressively and adapt. How you build that training stress is often somewhat unique to the individual so you can easily build a solid program based on a % of any number as long as you're pushing yourself hard enough but not too hard.

Thanks, Chris
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Re: Functional Power and Lactic Threshold [JReed] [ In reply to ]
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JollyRogers
Oct 16, 09 12:23
Post #13 of 14 (873 views)
The Allen/Coggan book calls for a 5 minute all-out interval prior to the 20 minute test.

I prefer to use critical power modeling with 5 and 20 minute periods. The two sessions occur at least two days, but no more than a week apart. After performing the 5 minute interval, I complete the rest of the power profile test.

Using the CP model with a 5 min power of 378 and a 20 minute power of 312, I get a CP of 290W. CP is close enough to FTP to set up training zones.
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Re: Functional Power and Lactic Threshold [Andrew Coggan] [ In reply to ]
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Alex Simmons
Oct 17, 09 1:46
Post #14 of 14 (783 views)
In Reply To:
In Reply To:
I assume you prefer the 2x20 minute test for FPT?

No.

In Reply To:
I agree and know that HR is variable...but don't you think LT is valuable info at all?

Not in the present context. You're comparing an indirect indicator of the exercise intensity (i.e., heart rate) measured on one occasion under one set of conditions to that measured on another occasion under a different set of conditions and asking "have I changed?". That is simply not a question that can be answered based on the data presented.

Which is a fine example of the Sin of Sins #3:
http://alex-cycle.blogspot.com/...s-testing-ftp-2.html
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