Keto and cycling
#51
Senior Member
That chart supports what I wrote. At about 65% fat usage drops and carbohydrate usage shoots up like a rocket. The study I read only tested three points: 65%, something less than 65%, and something greater than 65% (IIRC, 80%).
The Training Peaks article references work done by Len Kravitz. He has a blog I stumbled across several years ago that has good articles about exercise and links to other works. Worth a look. https://www.unm.edu/~lkravitz/Pages/articles.html
The Training Peaks article references work done by Len Kravitz. He has a blog I stumbled across several years ago that has good articles about exercise and links to other works. Worth a look. https://www.unm.edu/~lkravitz/Pages/articles.html
Last edited by guachi; 04-27-21 at 06:04 PM.
#53
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That chart supports what I wrote. At about 65% fat usage drops and carbohydrate usage shoots up like a rocket. The study I read only tested three points: 65%, something less than 65%, and something greater than 65% (IIRC, 80%).
The Training Peaks article references work done by Len Kravitz. He has a blog I stumbled across several years ago that has good articles about exercise and links to other works. Worth a look. https://www.unm.edu/~lkravitz/Pages/articles.html
The Training Peaks article references work done by Len Kravitz. He has a blog I stumbled across several years ago that has good articles about exercise and links to other works. Worth a look. https://www.unm.edu/~lkravitz/Pages/articles.html
The problem is that there's a fallacy involved with using exhaled gas to derive energy sources used. It was explained in one of my links, above. You can see the very large difference in fat oxidation.
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#54
Junior Member
I am trying a low-carb keto meal replacement shake. So far it looks good. It saves time when I need a quick nutritional meal. Just add powder, water to mix, shake and go. Currently, I am on https://gethlth.com/ meal shake.
#55
Senior Member
However, the graph points out that at 85% of VO2 max intensity - which for an elite athlete corresponds to FTP, roughly - we're talking about 2/3rds of energy being derived from carbohydrates. That's basically means that high performance cycling and not eating sufficient carbs are mutually incompatible.
(That elite athletes burn more fat across all, but especially higher intensities than untrained or moderately trained people isn't entirely new, by the way - but I haven't read any real studies which suggest there's any significant amount of fat burned at 100% of VO2max at all)
(That elite athletes burn more fat across all, but especially higher intensities than untrained or moderately trained people isn't entirely new, by the way - but I haven't read any real studies which suggest there's any significant amount of fat burned at 100% of VO2max at all)
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#58
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What's the video about. Sum it up for us and maybe I'll consider it worth watching.
#59
Newbie racer
However, the graph points out that at 85% of VO2 max intensity - which for an elite athlete corresponds to FTP, roughly - we're talking about 2/3rds of energy being derived from carbohydrates. That's basically means that high performance cycling and not eating sufficient carbs are mutually incompatible.
(That elite athletes burn more fat across all, but especially higher intensities than untrained or moderately trained people isn't entirely new, by the way - but I haven't read any real studies which suggest there's any significant amount of fat burned at 100% of VO2max at all)
(That elite athletes burn more fat across all, but especially higher intensities than untrained or moderately trained people isn't entirely new, by the way - but I haven't read any real studies which suggest there's any significant amount of fat burned at 100% of VO2max at all)
If they can do that even a % or two, that could prove useful. Perhaps. How shifting that specific part right is useful for an amateur or C-group rider is beyond me. Myself included. Again, swag.
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#60
Senior Member
Whether shifting the curve to the right helps elite athletes in shorter distance events? If fat adapted, it is possible to burn a high percentage of fat at 80-85% of VO2 max. Probably more advantageous for ultra endurance events.
https://www.sciencedirect.com/scienc...5003340#bb0050
https://ultrarunning.com/features/he...at-adaptation/
https://www.sciencedirect.com/scienc...5003340#bb0050
https://ultrarunning.com/features/he...at-adaptation/
#61
Newbie racer
If the existing inflection point is 65%, and a pro has an ftp of 420 that would correspond to 320w. Not something to sneeze at. Being able to shift that to the right say 2%, that means you could then have that point be at 330w. You're in the wheelhouse now of folks holding that for long periods in Paris Roubaix and classics. So, could mean a win or loss there depending on where that point lies for a person.
Again, fun swag wild talk. Probably totally wrong, but just having fun chatting about it.
Again, fun swag wild talk. Probably totally wrong, but just having fun chatting about it.
#62
Senior Member
Whether shifting the curve to the right helps elite athletes in shorter distance events? If fat adapted, it is possible to burn a high percentage of fat at 80-85% of VO2 max. Probably more advantageous for ultra endurance events.
https://www.sciencedirect.com/scienc...5003340#bb0050
https://ultrarunning.com/features/he...at-adaptation/
https://www.sciencedirect.com/scienc...5003340#bb0050
https://ultrarunning.com/features/he...at-adaptation/
So there's no net gain to be had from an bicycle racing point of view - if anything possibly a loss because cyclists spend more time at high percentage of VO2max than an ultra runner will and the ability to go in the red can often be decisive.
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#63
Senior Member
The problem is that the carb metabolism gets regulated down when you do keto fat adaptation stuff.
So there's no net gain to be had from an bicycle racing point of view - if anything possibly a loss because cyclists spend more time at high percentage of VO2max than an ultra runner will and the ability to go in the red can often be decisive.
So there's no net gain to be had from an bicycle racing point of view - if anything possibly a loss because cyclists spend more time at high percentage of VO2max than an ultra runner will and the ability to go in the red can often be decisive.
Was that your experience or do you have a reference to back that up? My 5 minute power (VO2 max proxy) was about the same whether keto fat adapted or a sugar burner. It was 3% higher as a fat burner but that is not significant
Cyclists actually spend a higher percentage of their time in Zone 2 sitting in the pack than a runner who has nowhere to hide (draft). If your hypothesis that VO2 max is blunted, then, this would be very harmful when a break is made.
#64
Senior Member
I don't have anything on VO2max being affected itself, but ability to process carbs is.
#65
Senior Member
Ok. You don't have any. Why do you think the ability to process carbs would be impacted? If anything, I would expect GLUT transporters to be upregulated. As long as the rider has glycogen, they have it to burn. If you have any studies, I would love to read them.
#66
Senior Member
Sure. Mind you this all involves getting athletes back on carbs following a stint of low carb diet leading up to a race than a lot of carbs to replenish glycogen stores in the day up to the test, not continous low carb.
For example:
https://pubmed.ncbi.nlm.nih.gov/32697366/
Only abstract available unfortunately:
https://www.jsams.org/article/S1440-...415-9/fulltext
These ones says the protocol above doesn't actually help nor impair performance but are good reading anyway especially as why a continous low carb diet isn't the subject of study:
https://pubmed.ncbi.nlm.nih.gov/33806822/
https://journals.physiology.org/doi/...2000.89.6.2413
A brief overview:
https://www.gssiweb.org/en/sports-sc...ce-performance
For example:
https://pubmed.ncbi.nlm.nih.gov/32697366/
Only abstract available unfortunately:
https://www.jsams.org/article/S1440-...415-9/fulltext
These ones says the protocol above doesn't actually help nor impair performance but are good reading anyway especially as why a continous low carb diet isn't the subject of study:
https://pubmed.ncbi.nlm.nih.gov/33806822/
https://journals.physiology.org/doi/...2000.89.6.2413
A brief overview:
https://www.gssiweb.org/en/sports-sc...ce-performance
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#67
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Fundamental shift in athletic eating regimes/paradigms possible based on this shift in thinking.
It won't happen over night as there are too many at risk of falling off their high horses but that is almost always the reason for continuing to do things wrong. Like rim brakes. LOL
#68
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The brain is the boss, not the muscles.
Fundamental shift in athletic eating regimes/paradigms possible based on this shift in thinking.
It won't happen over night as there are too many at risk of falling off their high horses but that is almost always the reason for continuing to do things wrong. Like rim brakes. LOL
Fundamental shift in athletic eating regimes/paradigms possible based on this shift in thinking.
It won't happen over night as there are too many at risk of falling off their high horses but that is almost always the reason for continuing to do things wrong. Like rim brakes. LOL
I will still pass on watching. If you can't put it to words, I'll wait and see what I can glean from others that might watch it and discuss it here.
#69
Senior Member
Well that pretty much describes every thing I've ever read about nutrition diets, fads and recommendations. Even the Jenny Craig and Weight Watcher commercials claim their paradigms is the breakthrough for all.
I will still pass on watching. If you can't put it to words, I'll wait and see what I can glean from others that might watch it and discuss it here.
I will still pass on watching. If you can't put it to words, I'll wait and see what I can glean from others that might watch it and discuss it here.
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#70
Senior Member
You will not be able to perform at any decent intensity for anything but short periods. High intensity (as measured as a % of threshold or of Vo2Max) requires mostly CHO as fuel.
If your goal is to just ride, you can ride at Fatmax or below that for a long time on a keto diet. But why limit yourself to that?
If your goal is to just ride, you can ride at Fatmax or below that for a long time on a keto diet. But why limit yourself to that?
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#71
Senior Member
Whether shifting the curve to the right helps elite athletes in shorter distance events? If fat adapted, it is possible to burn a high percentage of fat at 80-85% of VO2 max. Probably more advantageous for ultra endurance events.
https://www.sciencedirect.com/scienc...5003340#bb0050
https://ultrarunning.com/features/he...at-adaptation/
https://www.sciencedirect.com/scienc...5003340#bb0050
https://ultrarunning.com/features/he...at-adaptation/
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#72
Senior Member
My position is pretty simple. You can shift your fat utilization or RER to make you less dependant on carbs......up to almost 85% of VO2 max for very, very fit riders. Those numbers are in some of the studies I linked. This power level is beyond FTP for most riders. FTP is somewhere from 75-90% of VO2 max on almost all riders. 90% would be a super fit and super slowtwitch rider but not providing glucose and ultimately glyogen during a long ride is.....foolish.
#73
Senior Member
Studies which compare fit amateurs to elite athletes tend to find that their fat oxydation ramps down earlier and is less at any power output than it is for elite level riders (which to a great extent have chosen their parents more carefully; we don't have the genetics to get there). Our fit amateur who isn't ridicilously genetically blessed and doesn't train as much is going to derive more fuel from carbs.
The corrolary to that, as your aerobic fitness improves, your ability to utilize fat both in totality and at a higher % of your VO2max is going to shift anyway without any dietary intervention. The unanswered question is the value (or detriment) of dietary interventions; the one which gets tested the most, which is low carb for a short while leading up to a race then a big dose of carbs the day before a race to replenish glycogen reserves isn't looking very promising. Permanent low carb doesn't even get tested anymore, because what would be the point?
N=1, but from personal observation, after some three years of training and improved fitness which comes with it (even though my power didn't dramatically improve - depending on duration, my power is 5-12% up from 2019 power curves, sprint is virtually unchanged), I do find myself less reliant on eating. Last weekend I did a tempo ride - three and a half hours, 202W average, just on water - this I couldn't do in 2019 (it also happens they were waiting on me at a tavern with homemade fresh food, cake and wine which made stuffing my face with gels less appetizing ).
If you just train to get fitter, you'll be metabolizing more fat.
The corrolary to that, as your aerobic fitness improves, your ability to utilize fat both in totality and at a higher % of your VO2max is going to shift anyway without any dietary intervention. The unanswered question is the value (or detriment) of dietary interventions; the one which gets tested the most, which is low carb for a short while leading up to a race then a big dose of carbs the day before a race to replenish glycogen reserves isn't looking very promising. Permanent low carb doesn't even get tested anymore, because what would be the point?
N=1, but from personal observation, after some three years of training and improved fitness which comes with it (even though my power didn't dramatically improve - depending on duration, my power is 5-12% up from 2019 power curves, sprint is virtually unchanged), I do find myself less reliant on eating. Last weekend I did a tempo ride - three and a half hours, 202W average, just on water - this I couldn't do in 2019 (it also happens they were waiting on me at a tavern with homemade fresh food, cake and wine which made stuffing my face with gels less appetizing ).
If you just train to get fitter, you'll be metabolizing more fat.
Last edited by Branko D; 12-10-21 at 07:58 AM.
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#74
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Studies which compare fit amateurs to elite athletes tend to find that their fat oxydation ramps down earlier and is less at any power output than it is for elite level riders (which to a great extent have chosen their parents more carefully; we don't have the genetics to get there). Our fit amateur who isn't ridicilously genetically blessed and doesn't train as much is going to derive more fuel from carbs.
The corrolary to that, as your aerobic fitness improves, your ability to utilize fat both in totality and at a higher % of your VO2max is going to shift anyway without any dietary intervention. The unanswered question is the value (or detriment) of dietary interventions; the one which gets tested the most, which is low carb for a short while leading up to a race then a big dose of carbs the day before a race to replenish glycogen reserves isn't looking very promising. Permanent low carb doesn't even get tested anymore, because what would be the point?
N=1, but from personal observation, after some three years of training and improved fitness which comes with it (even though my power didn't dramatically improve - depending on duration, my power is 5-12% up from 2019 power curves, sprint is virtually unchanged), I do find myself less reliant on eating. Last weekend I did a tempo ride - three and a half hours, 202W average, just on water - this I couldn't do in 2019 (it also happens they were waiting on me at a tavern with homemade fresh food, cake and wine which made stuffing my face with gels less appetizing ).
If you just train to get fitter, you'll be metabolizing more fat.
The corrolary to that, as your aerobic fitness improves, your ability to utilize fat both in totality and at a higher % of your VO2max is going to shift anyway without any dietary intervention. The unanswered question is the value (or detriment) of dietary interventions; the one which gets tested the most, which is low carb for a short while leading up to a race then a big dose of carbs the day before a race to replenish glycogen reserves isn't looking very promising. Permanent low carb doesn't even get tested anymore, because what would be the point?
N=1, but from personal observation, after some three years of training and improved fitness which comes with it (even though my power didn't dramatically improve - depending on duration, my power is 5-12% up from 2019 power curves, sprint is virtually unchanged), I do find myself less reliant on eating. Last weekend I did a tempo ride - three and a half hours, 202W average, just on water - this I couldn't do in 2019 (it also happens they were waiting on me at a tavern with homemade fresh food, cake and wine which made stuffing my face with gels less appetizing ).
If you just train to get fitter, you'll be metabolizing more fat.
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#75
I tried it three years ago as part of my preparation for my first double century and finished it on a plain re-fried beans burrito for lunch and 5-6 UCAN bars. I was using it to loss some weight after being injured but stalled after 5-6 months. Performance-wise, I never recover to pre-injury level and was 10-20% below. I quit after 18 months experimentation and went back to my low carb life style. My experiment falls in line with Kolie Moore's podcast.
https://www.empiricalcycling.com/pod...tmax-fallacies
https://www.empiricalcycling.com/pod...re-looking-for
https://www.empiricalcycling.com/pod...tmax-fallacies
https://www.empiricalcycling.com/pod...re-looking-for