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Thoughts on calorie calculation - Aerobic/Anaerobic glycolysis

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Thoughts on calorie calculation - Aerobic/Anaerobic glycolysis

Old 06-07-21, 04:54 PM
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Originally Posted by GhostRider62
What is your question? What is too vague.

Any effort over 330-340 watts for you will have some contribution of that power coming from anaerobic substrates.

There is a limit to the duration of those efforts and despite what you wrote, they are not ALL aerobic. Some of that is anaerobic. If your 700 watts for 1 minute were truly all aerobic, you would be able to ride for much longer than 1 minute at that effort. Look up AWC, FRC. W' to see what I am referring to. OTOH if you are an Exercise Physiologist looking to split hairs on acronyms, I am out. Here is what Andrew Coggan says:
What, as in, I don't understand what you're writing because it was in response to something I didn't write. And your assertion that it depends on the effort doesn't make sense, either.

I never, at any point, said any particular effort was ALL aerobic. I said the majority of any effort over 40s is aerobic. That is, 51% or more of the energy required for an effort exceeding that duration is aerobic.

I think you got confused on what was actually written, which was a response to a statement about efforts being ~5 minutes or longer being mainly aerobic when it's actually a much shorter duration than that.

I'm not an exercise physiologist, but I do read well enough. And I certainly understand the things I write. And I certainly know when I don't write something and when I do.

Last edited by rubiksoval; 06-07-21 at 05:01 PM.
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Old 06-07-21, 06:22 PM
  #27  
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Originally Posted by rubiksoval
What, as in, I don't understand what you're writing because it was in response to something I didn't write. And your assertion that it depends on the effort doesn't make sense, either.

I never, at any point, said any particular effort was ALL aerobic. I said the majority of any effort over 40s is aerobic. That is, 51% or more of the energy required for an effort exceeding that duration is aerobic.

I think you got confused on what was actually written, which was a response to a statement about efforts being ~5 minutes or longer being mainly aerobic when it's actually a much shorter duration than that.

I'm not an exercise physiologist, but I do read well enough. And I certainly understand the things I write. And I certainly know when I don't write something and when I do.
Whatever.

What you wrote is wrong

You cannot do a "max effort" for 40 seconds as you originally wrote to which I responded.
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Old 06-07-21, 06:45 PM
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Originally Posted by GhostRider62
Whatever.

What you wrote is wrong

You cannot do a "max effort" for 40 seconds as you originally wrote to which I responded.
Yeah, you definitely can go do a max 40 second effort. And a max 40 minute effort. And a max four hour effort. And all of those are increasingly aerobic efforts.

So nah, I'm exactly right, and it seems you're just getting more and more confused.
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Old 06-08-21, 07:40 AM
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Originally Posted by rubiksoval
I said the majority of any effort over 40s is aerobic. That is, 51% or more of the energy required for an effort exceeding that duration is aerobic.
I don't believe this is correct.
At ~40 seconds, the majority of the energy produced *at that moment* will be generated through the aerobic pathway, but the majority of the energy used over the entire duration of the activity to that point will be anaerobic.
https://www.google.com/imgres?imgurl...MygAegUIARC0AQ
Current height of the curve vs area under the curve. You have to go somewhat past 40 seconds before half of the total amount of energy used for the entire activity is generated aerobically.
https://researchoutput.csu.edu.au/ws...9/PID+8029.pdf
Looking at this paper, you see that for men, ~60% of the energy used in a 400m sprint is anaerobic, despite being longer than 40 seconds. The 50/50 threshold happens somewhere between 400 and 800 meters, so probably around 1:20 or so.
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Old 06-08-21, 04:18 PM
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Originally Posted by OBoile
I don't believe this is correct.
At ~40 seconds, the majority of the energy produced *at that moment* will be generated through the aerobic pathway, but the majority of the energy used over the entire duration of the activity to that point will be anaerobic.
https://www.google.com/imgres?imgurl...MygAegUIARC0AQ
Current height of the curve vs area under the curve. You have to go somewhat past 40 seconds before half of the total amount of energy used for the entire activity is generated aerobically.
https://researchoutput.csu.edu.au/ws...9/PID+8029.pdf
Looking at this paper, you see that for men, ~60% of the energy used in a 400m sprint is anaerobic, despite being longer than 40 seconds. The 50/50 threshold happens somewhere between 400 and 800 meters, so probably around 1:20 or so.
That's been the traditional thinking. That's why Gastin's work was so interesting. It showed that aerobic changeover happening substantially earlier than anyone else believed. Maybe it's not 40. Maybe it's 45 or 50. I was going off memory.

Ah, 46 + / -4%. for 400m, which is around 43-44 seconds. So about 45-50 seconds for majority work.

400m 46 +/-4% aerobic 25% aerobic 21-25%
800m 69 +/-4% aerobic 50% aerobic 19-23%
1,500m 83 +/-3% aerobic 65% aerobic 18-21%

Sources: AOD data: "Energy system contribution during 400m to 1,500m running, by Matt R. Spencer, Paul B. Gastin and Warren R. Payne. New studies in Athletics, no. 4/1996.

Oxygen debt data: "Keep on running. The Science of Training and Performance". Eric Newsholme, Tony Leech, Glenda Duester, -1994 -John Wiley & Sons Ltd.

The new data is quite sensational, as it emphasizes the importance of aerobic power not only for long distances, but also for middle distances like 800m and 1,500m.As you can see, the differences between the new and old percentages are large compared to the previous inaccurate data: they are approximately 20%. If you use traditional % calculations on, for example, the 800m, the difference between 69 and 50 is:
Here's an old thread. Some links are dead, but maybe that can lead you to the original study if interested. https://www.letsrun.com/forum/flat_r...?thread=927991

In any case, despite all the minutiae, it's not 5 minutes. And it's apparently not 1:20, either.

So much aerobic need for even short durations, which was the point all along.

Last edited by rubiksoval; 06-08-21 at 04:27 PM.
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Old 06-08-21, 05:24 PM
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Originally Posted by rubiksoval
That's been the traditional thinking. That's why Gastin's work was so interesting. It showed that aerobic changeover happening substantially earlier than anyone else believed. Maybe it's not 40. Maybe it's 45 or 50. I was going off memory.

Ah, 46 + / -4%. for 400m, which is around 43-44 seconds. So about 45-50 seconds for majority work.



Here's an old thread. Some links are dead, but maybe that can lead you to the original study if interested. https://www.letsrun.com/forum/flat_r...?thread=927991

In any case, despite all the minutiae, it's not 5 minutes. And it's apparently not 1:20, either.

So much aerobic need for even short durations, which was the point all along.
The study I posted was from the same year as that thread (and newer than the Gastin study), and was almost identical (59% anaerobic vs 57% for the 400m which is longer than 40 seconds) with the numbers in the OP. In fact, it is posted on that very thread further down. Based on the numbers from either study, it's highly unlikely that the total anaerobic contribution drops below 50% before a minute.

Edit to add: also, the average 400m time in the study I posted was 52 seconds. So, at 52 seconds, 59% of the work was still anaerobic.

Last edited by OBoile; 06-08-21 at 05:45 PM.
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