Super review!! Thank you so much for using your expertise to explain this article, its implications, the nuances, and adding in some of the history to provide a frame of context. It will be very interesting to see where this ends up going! I hope that he/team can continue this research.
Thank you Diana! 👊 I hope so too. Would love for the research to eventually establish broad ranges, and then discuss methods of individualization, rather than such broad recommendations. I think that's where we're heading.
Honest question… The study found higher carbohydrate oxidation rates in the 1:0.8 group, which is consistent with a previous study by O’Brien et al in 2013, but the study also found that fat utilisation decreased, and was actually higher in the 2:1 group. This is quite important (I think) as it suggests that the 1:0.8 group simply switched from fat to enhanced carbohydrate metabolism, without any performance advantage indicated. Since during longer/intense sessions, both fats and carbohydrates are burned as fuels, it does not make sense to me to follow this particular carbohydrate-feeling strategy which forces the body to burn less of its already abundant fuel (fat). The study also concluded that the 1:0.8 group did not benefit from any carbohydrate-sparing effect, and this was despite the 1:0.8 group consuming 30g more carbohydrates per hour. What are your thoughts on this?
Make the athletes go for more hours, and the higher exogenous carb utilization will pay off in performance benefit. Just because one has higher fat oxidation does not necessarily mean anything good or bad about an approach. It just means there's not as much carb available to burn.
Great observation about water consumption indoors vs. outdoors. Usually I take in twice as much water indoors than outdoors, about 1,3 l/h indoors (= 2 bottles).
Really interesting stuff here. Anecdotal, but I have been pushing 120g /hr in my races this year. I am a Cat 1 MTB racer. 6' 1" and 190lbs. No problem with gut and think if I had more water and a less concentrated mix I could even do more. Sodium is key as well.
On looking for relationships not determined out of statistical tests "That's a dangerous game if that's all you're doing" - there's so much bad statistics practice in sports science. Nice to hear someone differentiate between empirical knowledge, a priori knowledge, and the process of establishing high probability lines of enquiry
Glad you appreciate that we fully understand the inappropriate use of data here. And that sometimes it makes sense, in the real world, when you have NO other data, and it so strongly aligns with extensive anecdotal evidence.
Good stuff here. Quite dense. Need to watch and rewatch. But definitely worth the time for enthusiasts trying go get a good picture on sports nutrition.
Appreciate your disclaimers of breaking scientific rules at as well as the “wild” speculations / extrapolation. Informative. Entertaining. Let’s go for 120g CHO/h!!
@@Saturday_ProFuel I am doing a PhD and can attest that scientific rigor is good but has its limitations. But yes, it’s professional and really diligent of you to do those “disclaimers”.
Hi. Im just beginning to follow you. Im read and listen alot to folks that study nutrition. Im a big beleaver in carbs in training. Im 52 years old and a cat 5 rider in races that last about 2 hours. I take in 90 g Hr. But mcy friends say we dont need so much, because we don't use so many watts that the pros do. I can't get in there head. Im the only one, that read about nutrition, but still... So one quistion. Should Even us older riders take in alot of carbs in races and training. I do think i know the answer, but I will show you're answer to my friends
Yes, in fact, often it's the lesser-experienced folks who need more carbs per hour because they have less well-developed aerobic / fat-burning ability. Lower fitness to body size usually means more carbs needed per watt :) That said, if you're riding super super easy, you don't always need higher carbs and sometimes it's best to scale back a bit, for those easiest training days.
Always enjoy listening to Dr Tim Podlogar. Very interesting study. Something I was thinking about is if the riders were 80kg and consuming 120g ph what would a 50kg rider used? The same or less carbs per hr?
Great question. Body size plays less of a role in optimality than fitness. But gut tolerance is the primary limiting factor. Michelle regularly consumes 100-130g/hr, weighing ~63kg. If there are differences based on body weight, they are small differences. Other considerations like gut tolerance and balancing satiety issues outside of training tend to matter more.
@@Richz2 Yes somewhat, but we are more alike than we are different. We're building this youtube channel to make it easier to understand exactly how to test things and where you should start. Our app should also help folks tremendously with that. Combined, our app as a "coach in your pocket" and our youtube channel should make for some well-informed and intelligently fueled folks. :)
Love it. "You're not supposed to break the rules by changing these charts, but I'm going to do it anyway." Would love to see additional information around cooling and sodium and 6+ hours of workout, but yeah we're not going to see that last one even for college students who are desperate for money. So since we're just shooting from the hip, would you want to ramp up in the first hours from 90 to 120g within that first 3 hours? thinking Unbound 200 and other 10+ hour tempo/sweetspot efforts.
We still recommend even fueling throughout unless intensity is substantially lower in the beginning of a ride. There is a 45-90 minute delay before those carbs you consume are actually burned, so keep that in mind if you're planning any lower rates of fuel intakes for any portion of an activity.
@@Saturday_ProFuel Do you think the >>3hr timeframe needs to be continuous? In reality, many rides with 3+ hrs of active time would be more like 3.5-4 hrs with stops (e.g. waiting at the top of a hill for a mate, water refills, toilet...). I know research has people just go continuously, but it is different outside the lab, of course.
@@dianahellman9254 if anything, higher carb intake on a per hour of riding basis, but also on a total time basis, could be more beneficial when breaks are implemented because it could promote glycogen repletion at a faster rate during those breaks than a lower carb intake. One could argue the opposite effect (less difference) might be found with discontinuous riding, based on the blood sugar rebounding positively during breaks even in a lower carb condition. Needs more research.
Unknown as of writing this. Certainly lots of companies have doubled down on the 1:0.8 (ie. 5:4) ratio, so you can expect that to stick for the next decade or so. :) Whether it's 4:3, 1:1, 5:4, 4:5, changes with intake rate, changes with gut training, changes with intensity, or changes with anthropometric data or fitness, all remains to be seen. Lots of years of research yet to come.
@@Saturday_ProFuel I mean, You mentioned about eating more, right? but guts limit is still 60g/h of glucose (malto...) ? so the only thing we can increase is fructose (from 30g to more). Or can we absorb more glucose/malto... as well ?
Do you have any nutrition tips for grass doubles volleyball? My Fitbit says I’m burning 630 calories per hour with my heart rate in the fat burn zone and reaches into the cardio zone. Avg HR 128 peak at 158 bpm
Great question. Should probably fuel during it just like an endurance athlete would. Carbs are super important for explosive power, especially when there is an ongoing cardio demand like you've demonstrated. Our CTO is a volleyball player, actually, and he's used our app for all his volleyball tournaments using the "Run" activity setting on "recovery" or "low aerobic" intensity. Shoot us an email if you have any questions. ("contact us" within the app goes directly to our inbox)
@@Saturday_ProFuel I’m checking out the app now. Thanks I’m playing a tournaments almost every weekend I’d love to reach out to your CTO and pick his brain sometime.
Wouldn't this end being like most other things, that some people will do better at higher rates, where others will not show any real benefit above 90. So best idea would be to test these ideas to determine whether or not you feel, think you feel, or don't think you see any real benefit above 90ph
Yep. Individual testing is wise. Make sure to test in the 3- to 6-hour activity duration range. That's when super high-carb strategies really start to pay dividends.
This is very interesting! However the studies are done on only men. I’d love to know the conclusions or approximate conclusions from using women in the study too.
Is it fair to say it depends? Sounds like this study along with voice over and comments doesn't necessarily contradict the work by Jeukendrup on 2:1, but compliments it in that the total amount injested and time of activity should define your ratio. I.e. If you have a 3+ hour event and CAN injest 120g/h, 1:.8 is better; but if you are doing less than 3 hr 90g/hr at 2:1 is better?
We initially thought that too. But on close inspection of the literature and app user experience, it appears that closer to 1:1 is probably better for the lower intake rates too, if we had to make an educated guess at the moment. There's limited hard research evidence either way.
First half super interesting, but I am afraid second is going a bit too far with data. I would have simply suggested these as possible hypothesis for future studies
Actually there is no resemblance between this study and me. I’m a female and they never do studies on females so I’m going to ignore this . There are HUGE differences so I feel like this is irrelevant for me specifically. Women are not small men.
Hi Anat, Alex here. Thank you for taking the time to say this because it needs to be said, though at this point, it's a shame that it still needs to be. You're right. Women are not small men. (ROAR by Stacy Sims is one of our favorite books!) Michelle Howe, sport RD, and cofounder of our app and channel, routinely uses similar carb doses as those studied here. She's even consumed upwards of 130g/h for some of her longer riding efforts. In her experience the difference between fueling with 100g/h vs. 115g/h during a 4 or 5 hour ride, is quite noticeable in terms of energy levels. Body weight ~63kg. She regularly recommends the same for her peers, when appropriate, pending about a dozen factors, most notably gut issue risk and experience executing high carb fueling strategies. If anything, Michelle tends to recommend higher carbs than I do! Call me a little soft. Stay tuned for the next video she is featured in. I think you'll enjoy getting to know her a bit more. When we interview Dr. Podlogar about this paper next week, we may offer to help fund some research in women athletes in the future. We hope that you'll subscribe if for no other reason, just to keep us honest. Thank you again, Anat. We value you your feedback dearly.
How much you need depends on how much you're burning. The other fuel, of course, is fat, of which we already have plenty. If you can ride at 300w but use 50% glycogen and 50% fat, you will need to intake half as much carbohydrates as someone who can ride at 300w using 100% glycogen and 0% fat. Training to intake more carbohydrates is going to make you less efficient and therefore you're going to always NEED more. A large part of training should be teaching the body to be more efficient, i.e. when under fuelled.
Thank you very much for this thoughtful comment! We might differ a little in our understanding here, so here's where we might differ: intaking half the carbs because half your fuel is coming from fat currently, might not be the best way to optimize performance. It might still be optimal to intake more carbs than you're burning so that they're in your system ahead of time as glycogen stores start to run lower. In fact, a lower chronic intake of carbs during training can actually make you less good at using carbs as fuel which can hurt performance out beyond about 90 minutes, regardless of the intensity, and can definitely harm performance at higher intensities even of much shorter duration. Burning fat is not a more efficient energy source. It is less efficient. That's been very well examined in the scientific literature. Dr. Louise Burke's work is a great resource there. We are on a mission to show people that they don't need to train for those under-fueled scenarios because with good planning it's often very possible to avoid them entirely. We might have different opinions on a couple little things here but we're still really glad you're here with us! And thank you for taking the time to share with us.
You sound like our lead hardware engineer (yes we have a dormant hardware department) - "if brute force isn't working, you're not using enough of it." :)
I approve the data fudging☝️🫣🤣. For me it's clear that endogenous carb consumption will continue even when maxing out your exogenous intake as the power outputs would demand this. If we take just 150w at the pedals, which is low for most people (150j/s) => 540kj/hr = 129 Cal. Now the body is approx 25% efficient at producing this power, bcos we also generate a lot of heat, that means in totality the body is consuming/converting approx. 516Cal/hr which is equivalent to 129g sugar/hr. This is overly simplified because at 150w at the pedals most athletes will be doing that with a large % of fat burn but what Im showing is that its easy to see that our bodies demand for energy easily outstrips most of our ability to replenish exogenously on carbs hence the body will tap in endogenous stores of carbs & fats. Take this power output to 200 or 300w and the exogenous intake of carbs definitely cant keep up so you will be maxing your endogenous burn and unless you are very fit with larger than most glycogen stores and can also efficiently tap into fat stores for much of this power your are going to burn out very quickly. My question would be if the research is saying that 90g/hr is the upper limit of oxidation then if someone is taking 120g/hr then where the heck is the other 30g/hr going? is it pooling in the intestines waiting in the queue to be processed or what? If really 90g/hr is the limit and those carbs are pooling in the intestines basically creating a more and more hypertonic environment then explosive diarrhea or nausea with vomiting would ensue and indeed this can happen (most athletes can attest to this at some point I think). I would therefore suggest those that can tolerate 120g/hr or even higher without the GI distress and nausea are in-fact metabolising it otherwise where is the glucose & fructose going??
Thanks for breaking down the study, I was left a bit unsure of the takeaways after listening to the podcast on TR.
You're welcome! Forward looking discussion coming when we chat with Dr. Podlogar next week.
Super review!! Thank you so much for using your expertise to explain this article, its implications, the nuances, and adding in some of the history to provide a frame of context. It will be very interesting to see where this ends up going! I hope that he/team can continue this research.
Thank you Diana! 👊 I hope so too. Would love for the research to eventually establish broad ranges, and then discuss methods of individualization, rather than such broad recommendations. I think that's where we're heading.
I had read the article, but it now makes more sense to me. Well done!
Really glad to hear that. Thanks for being with us.
Awesome content. Much appreciated from a fellow WWU MS Kin grad.
Thank you! Glad you're enjoying it. Go Vikings!
Honest question… The study found higher carbohydrate oxidation rates in the 1:0.8 group, which is consistent with a previous study by O’Brien et al in 2013, but the study also found that fat utilisation decreased, and was actually higher in the 2:1 group. This is quite important (I think) as it suggests that the 1:0.8 group simply switched from fat to enhanced carbohydrate metabolism, without any performance advantage indicated. Since during longer/intense sessions, both fats and carbohydrates are burned as fuels, it does not make sense to me to follow this particular carbohydrate-feeling strategy which forces the body to burn less of its already abundant fuel (fat). The study also concluded that the 1:0.8 group did not benefit from any carbohydrate-sparing effect, and this was despite the 1:0.8 group consuming 30g more carbohydrates per hour.
What are your thoughts on this?
Make the athletes go for more hours, and the higher exogenous carb utilization will pay off in performance benefit. Just because one has higher fat oxidation does not necessarily mean anything good or bad about an approach. It just means there's not as much carb available to burn.
Awesome vid! Can’t wait to see you and Dr. Tim bouncing ideas off each other, hope it’s a long one!
Us too!
Great observation about water consumption indoors vs. outdoors. Usually I take in twice as much water indoors than outdoors, about 1,3 l/h indoors (= 2 bottles).
Us too! (unless we're in AZ)
Really interesting stuff here. Anecdotal, but I have been pushing 120g /hr in my races this year. I am a Cat 1 MTB racer. 6' 1" and 190lbs. No problem with gut and think if I had more water and a less concentrated mix I could even do more. Sodium is key as well.
💯
Excellent video editing! 👍
We'd be nowhere without our editor.
On looking for relationships not determined out of statistical tests "That's a dangerous game if that's all you're doing" - there's so much bad statistics practice in sports science. Nice to hear someone differentiate between empirical knowledge, a priori knowledge, and the process of establishing high probability lines of enquiry
Glad you appreciate that we fully understand the inappropriate use of data here. And that sometimes it makes sense, in the real world, when you have NO other data, and it so strongly aligns with extensive anecdotal evidence.
So interesting. Thanks for everything you do. It's really appreciated by a lot of us.
You're very welcome.
Thank you for taking the time to write us here!
Good stuff here. Quite dense. Need to watch and rewatch. But definitely worth the time for enthusiasts trying go get a good picture on sports nutrition.
Glad you enjoyed it. Feel free to re-watch ;)
Great video 📼 👍
Thank you Patrick!
Appreciate your disclaimers of breaking scientific rules at as well as the “wild” speculations / extrapolation. Informative. Entertaining.
Let’s go for 120g CHO/h!!
You're very welcome. We'll always point out when we're not following scientific rigor.
@@Saturday_ProFuel I am doing a PhD and can attest that scientific rigor is good but has its limitations. But yes, it’s professional and really diligent of you to do those “disclaimers”.
Hi. Im just beginning to follow you. Im read and listen alot to folks that study nutrition. Im a big beleaver in carbs in training. Im 52 years old and a cat 5 rider in races that last about 2 hours. I take in 90 g Hr.
But mcy friends say we dont need so much, because we don't use so many watts that the pros do. I can't get in there head. Im the only one, that read about nutrition, but still...
So one quistion.
Should Even us older riders take in alot of carbs in races and training. I do think i know the answer, but I will show you're answer to my friends
Yes, in fact, often it's the lesser-experienced folks who need more carbs per hour because they have less well-developed aerobic / fat-burning ability. Lower fitness to body size usually means more carbs needed per watt :)
That said, if you're riding super super easy, you don't always need higher carbs and sometimes it's best to scale back a bit, for those easiest training days.
Always enjoy listening to Dr Tim Podlogar. Very interesting study. Something I was thinking about is if the riders were 80kg and consuming 120g ph what would a 50kg rider used? The same or less carbs per hr?
Great question. Body size plays less of a role in optimality than fitness. But gut tolerance is the primary limiting factor.
Michelle regularly consumes 100-130g/hr, weighing ~63kg.
If there are differences based on body weight, they are small differences. Other considerations like gut tolerance and balancing satiety issues outside of training tend to matter more.
@@Saturday_ProFuel Thanks for the reply. I guess every individual if different and you just need to see what is best for you.
@@Richz2 Yes somewhat, but we are more alike than we are different.
We're building this youtube channel to make it easier to understand exactly how to test things and where you should start.
Our app should also help folks tremendously with that.
Combined, our app as a "coach in your pocket" and our youtube channel should make for some well-informed and intelligently fueled folks. :)
Very good. Thank you!
You're welcome. And, thank YOU.
Love it. "You're not supposed to break the rules by changing these charts, but I'm going to do it anyway." Would love to see additional information around cooling and sodium and 6+ hours of workout, but yeah we're not going to see that last one even for college students who are desperate for money. So since we're just shooting from the hip, would you want to ramp up in the first hours from 90 to 120g within that first 3 hours? thinking Unbound 200 and other 10+ hour tempo/sweetspot efforts.
We still recommend even fueling throughout unless intensity is substantially lower in the beginning of a ride. There is a 45-90 minute delay before those carbs you consume are actually burned, so keep that in mind if you're planning any lower rates of fuel intakes for any portion of an activity.
Looks like it may be good to err on the high side, especially if you know your stomach can take it.
Agreed, especially when training or racing >>3 hours.
@@Saturday_ProFuel Do you think the >>3hr timeframe needs to be continuous? In reality, many rides with 3+ hrs of active time would be more like 3.5-4 hrs with stops (e.g. waiting at the top of a hill for a mate, water refills, toilet...). I know research has people just go continuously, but it is different outside the lab, of course.
@@dianahellman9254 if anything, higher carb intake on a per hour of riding basis, but also on a total time basis, could be more beneficial when breaks are implemented because it could promote glycogen repletion at a faster rate during those breaks than a lower carb intake.
One could argue the opposite effect (less difference) might be found with discontinuous riding, based on the blood sugar rebounding positively during breaks even in a lower carb condition.
Needs more research.
Interesting discussion. If 120g/hr was tolerable + salt and liquid amount was optimised then thats important they shouldve considered/measured that.
Thank you!! Details matter for sure.
so what's the recommended ratio (glucose to fructose) for 120g carbs per hour? 5:4 ? ('the new' standard) ?
Unknown as of writing this. Certainly lots of companies have doubled down on the 1:0.8 (ie. 5:4) ratio, so you can expect that to stick for the next decade or so. :) Whether it's 4:3, 1:1, 5:4, 4:5, changes with intake rate, changes with gut training, changes with intensity, or changes with anthropometric data or fitness, all remains to be seen. Lots of years of research yet to come.
@@Saturday_ProFuel I mean, You mentioned about eating more, right? but guts limit is still 60g/h of glucose (malto...) ? so the only thing we can increase is fructose (from 30g to more). Or can we absorb more glucose/malto... as well ?
@@razorree Over time, both probably adapt to allow more to be consumed per hour. Fructose tends to adapt more. Does that answer your question?
@@Saturday_ProFuel Thanks for clarification :)
@@razorree 👊
Do you have any nutrition tips for grass doubles volleyball? My Fitbit says I’m burning 630 calories per hour with my heart rate in the fat burn zone and reaches into the cardio zone. Avg HR 128 peak at 158 bpm
Great question. Should probably fuel during it just like an endurance athlete would. Carbs are super important for explosive power, especially when there is an ongoing cardio demand like you've demonstrated. Our CTO is a volleyball player, actually, and he's used our app for all his volleyball tournaments using the "Run" activity setting on "recovery" or "low aerobic" intensity. Shoot us an email if you have any questions. ("contact us" within the app goes directly to our inbox)
@@Saturday_ProFuel I’m checking out the app now. Thanks I’m playing a tournaments almost every weekend I’d love to reach out to your CTO and pick his brain sometime.
@@srjt9000 Saw you might have joined our member hub. Reach out to him there!
@@Saturday_ProFuel Thanks will do!
Wouldn't this end being like most other things, that some people will do better at higher rates, where others will not show any real benefit above 90. So best idea would be to test these ideas to determine whether or not you feel, think you feel, or don't think you see any real benefit above 90ph
Yep. Individual testing is wise. Make sure to test in the 3- to 6-hour activity duration range. That's when super high-carb strategies really start to pay dividends.
This is very interesting! However the studies are done on only men. I’d love to know the conclusions or approximate conclusions from using women in the study too.
Is it fair to say it depends? Sounds like this study along with voice over and comments doesn't necessarily contradict the work by Jeukendrup on 2:1, but compliments it in that the total amount injested and time of activity should define your ratio. I.e. If you have a 3+ hour event and CAN injest 120g/h, 1:.8 is better; but if you are doing less than 3 hr 90g/hr at 2:1 is better?
We initially thought that too. But on close inspection of the literature and app user experience, it appears that closer to 1:1 is probably better for the lower intake rates too, if we had to make an educated guess at the moment. There's limited hard research evidence either way.
First half super interesting, but I am afraid second is going a bit too far with data. I would have simply suggested these as possible hypothesis for future studies
You're completely right. Forgive us!
Actually there is no resemblance between this study and me. I’m a female and they never do studies on females so I’m going to ignore this . There are HUGE differences so I feel like this is irrelevant for me specifically. Women are not small men.
Hi Anat,
Alex here. Thank you for taking the time to say this because it needs to be said, though at this point, it's a shame that it still needs to be. You're right. Women are not small men.
(ROAR by Stacy Sims is one of our favorite books!)
Michelle Howe, sport RD, and cofounder of our app and channel, routinely uses similar carb doses as those studied here. She's even consumed upwards of 130g/h for some of her longer riding efforts. In her experience the difference between fueling with 100g/h vs. 115g/h during a 4 or 5 hour ride, is quite noticeable in terms of energy levels. Body weight ~63kg.
She regularly recommends the same for her peers, when appropriate, pending about a dozen factors, most notably gut issue risk and experience executing high carb fueling strategies.
If anything, Michelle tends to recommend higher carbs than I do! Call me a little soft.
Stay tuned for the next video she is featured in. I think you'll enjoy getting to know her a bit more.
When we interview Dr. Podlogar about this paper next week, we may offer to help fund some research in women athletes in the future.
We hope that you'll subscribe if for no other reason, just to keep us honest.
Thank you again, Anat. We value you your feedback dearly.
“What’s your carbohydrate intake-split for the next race: positive or negative?!”
😏
How much you need depends on how much you're burning. The other fuel, of course, is fat, of which we already have plenty. If you can ride at 300w but use 50% glycogen and 50% fat, you will need to intake half as much carbohydrates as someone who can ride at 300w using 100% glycogen and 0% fat. Training to intake more carbohydrates is going to make you less efficient and therefore you're going to always NEED more. A large part of training should be teaching the body to be more efficient, i.e. when under fuelled.
Thank you very much for this thoughtful comment! We might differ a little in our understanding here, so here's where we might differ: intaking half the carbs because half your fuel is coming from fat currently, might not be the best way to optimize performance. It might still be optimal to intake more carbs than you're burning so that they're in your system ahead of time as glycogen stores start to run lower. In fact, a lower chronic intake of carbs during training can actually make you less good at using carbs as fuel which can hurt performance out beyond about 90 minutes, regardless of the intensity, and can definitely harm performance at higher intensities even of much shorter duration. Burning fat is not a more efficient energy source. It is less efficient. That's been very well examined in the scientific literature. Dr. Louise Burke's work is a great resource there.
We are on a mission to show people that they don't need to train for those under-fueled scenarios because with good planning it's often very possible to avoid them entirely.
We might have different opinions on a couple little things here but we're still really glad you're here with us! And thank you for taking the time to share with us.
If you torture the data enough it will admit to anything.
You sound like our lead hardware engineer (yes we have a dormant hardware department) - "if brute force isn't working, you're not using enough of it." :)
I approve the data fudging☝️🫣🤣. For me it's clear that endogenous carb consumption will continue even when maxing out your exogenous intake as the power outputs would demand this. If we take just 150w at the pedals, which is low for most people (150j/s) => 540kj/hr = 129 Cal. Now the body is approx 25% efficient at producing this power, bcos we also generate a lot of heat, that means in totality the body is consuming/converting approx. 516Cal/hr which is equivalent to 129g sugar/hr. This is overly simplified because at 150w at the pedals most athletes will be doing that with a large % of fat burn but what Im showing is that its easy to see that our bodies demand for energy easily outstrips most of our ability to replenish exogenously on carbs hence the body will tap in endogenous stores of carbs & fats. Take this power output to 200 or 300w and the exogenous intake of carbs definitely cant keep up so you will be maxing your endogenous burn and unless you are very fit with larger than most glycogen stores and can also efficiently tap into fat stores for much of this power your are going to burn out very quickly.
My question would be if the research is saying that 90g/hr is the upper limit of oxidation then if someone is taking 120g/hr then where the heck is the other 30g/hr going? is it pooling in the intestines waiting in the queue to be processed or what? If really 90g/hr is the limit and those carbs are pooling in the intestines basically creating a more and more hypertonic environment then explosive diarrhea or nausea with vomiting would ensue and indeed this can happen (most athletes can attest to this at some point I think). I would therefore suggest those that can tolerate 120g/hr or even higher without the GI distress and nausea are in-fact metabolising it otherwise where is the glucose & fructose going??
The math don’t lie and carbs don’t vanish!