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While elite professional athletes continue to raise the ceiling on carbohydrate intake, we detail the research that says it isn’t appropriate, or healthy, for most athletes to do so.
Episode Transcript
[00:00:00] Chris Case: Hey everyone, welcome to Fast Talk, your source for the science of endurance performance. I’m your host, Chris Case, here with Trevor Connor and Julie Young. Are we in the midst of a carb revolution? If you pay attention to endurance sports media, you’d be hard-pressed to think otherwise. It seems that every week there’s a new story about an athlete consuming a hundred and twenty, a hundred and forty, even a hundred and sixty grams of carbohydrates per hour to fuel some record-breaking performance.
Impressive? Not really. The media has made it seem like having a higher carb intake is akin to having a higher FTP, and that’s just not the way it works. Importantly, the implication of these articles and reports is that the high doses of sugar are the reason for the astounding performances we see so frequently.
Today, we look at new research that summarizes the science behind the ultra-high carbohydrate craze to understand if there is any validity to the claim that super fueling is the reason for these astonishing achievements. We discuss three main points. Is there a dose-dependent relationship between ingestion rates and performance benefits?
Two, what could be the reasons, if any, why these ultra-high quantities are leading to faster times and stronger performances? And three, what are the health risks associated with high ingestion of carbs? We also discuss if there is any reason at all why an amateur should be consuming over ninety grams of carbs to fuel their performances.
All that and much more today on Fast Talk. It’s time to fact-check the carbohydrate frenzy. Let’s make you fast
[00:01:44] Trevor Connor: Before we dive into the episode, we’d like to introduce you to our MetPro Performance Minute. You sent us your most pressing nutrition questions. Here’s MetPro founder Angela Poley taking a minute to give you an answer Okay, Angela, I have a question for you, and this is one I love because people use the term metabolism all the time with me and don’t really understand what it means.
But I hear this, “I think I crashed my metabolism. My metabolism is slowed down.” So my question is, what does that really mean? Yeah.
[00:02:16] Angelo Poli: Is, is that a thing? And what’s actually happening on a biological level? It is a thing. It’s not exactly crashing. It’s actually optimizing. It’s adapting to your input. So what happens is our metabolism…
And we have this very well studied now. The clinical research on this is substantial. In fact, in some studies, they took a group of high school and college-age athletes, and they actually had them sit in a chamber and play video games, and they spent a couple days overfueling them and tracked their metabolic rate, and a few days underfueling them, and it was staggering to see just how flexible our metabolic rate can be and how much it adapts.
So when somebody says, “I crashed my metabolism,” usually they went on a diet, they ate less, they restricted their intake, and now the metabolism has done its job. It acclimated to recreate homeostasis, that’s weight maintenance, performance maintenance, to this degree they can, at that new intake level. And so that’s why it’s so critical for especially performance athletes, especially endurance athletes, to know where their metabolic rate is at and how their body is performing in relation to the fuel taking in.
Because you can’t change the laws of thermodynamics. You do have to restrict if you’re trying to reduce your body fat percentage or your weight. But understanding that your metabolism is the gatekeeper to so many different levels of performance and longevity, that you wanna honor it and respect it, so you want to know how much to restrict, how long to restrict for, and how to recuperate and recover after a period of restriction.
[00:04:10] Trevor Connor: So I mean, this is getting back to kind of an evolutionary survival mechanism, which is you can’t survive for long if you are burning more than what you’re consuming. So our bodies are amazing in saying, “Okay, I’m not getting enough fuel. I need to start burning less so that we can survive in the long term,” is basically what you’re saying.
[00:04:28] Angelo Poli: I would say our bodies are designed to massively acclimate under extreme duress. You spend time in the sun, your pigment changes, and your skin darkens. You do VO2 max training, and your heart- Actually improves in its capacity. You lift heavy weights, your muscles hypertrophy. Why would we think that our metabolism is any different?
You see, our bodies are marvelous in its ability to adapt to the circumstance that we create for it. So create a good one. Force it to adapt to what you want it to adapt to, and don’t always be reactionary.
[00:05:10] Trevor Connor: So that leads to the obvious question of if you’re trying to lose weight, is it always a losing proposition where your body’s gonna adapt and you stop losing weight, or are there strategies to get around that?
[00:05:21] Angelo Poli: Absolutely, there’s strategies to get around it. So it is true that if you are losing weight, you have to mechanically be in a deficit for a time, and your metabolic rate will be chasing that deficit. But that’s why we use cycles. We use cycles when we’re in our training and our– we’re doing our endurance work.
We’re not always pushing max PRs every single ride, right? Our bodies would burn out if we did that. So it’s the same exact way with our nutrition. We want to plan for and be cyclical with our nutrition, always planning to bring our nutrition intake up when we can for sustained amounts of times. And by the way, that needs to be your maintenance.
And one important little tip I’ll leave us with, I don’t want to go too long on this, but most people when they express to me what they believe their ideal body weight is, and I’m just picking a round figure here. Someone says, “I want to weigh two hundred pounds,” or, “I want to weigh a hundred and fifty pounds.”
I have to diet them down to one forty-seven or one forty-eight because I need to increase their fuel and actually have them gain weight back up to their maintenance. Otherwise, they’re never going to be eating optimal to fuel their body optimally at the highest intake they can while sustaining that weight.
So understanding the dynamics of what cyclical dieting and nutrition actually looks like in a performance world, it really changes the dynamics, and it can really transform your performance.
[00:06:49] Trevor Connor: Angelo, appreciate all this. Where can we go to learn more about this?
[00:06:53] Angelo Poli: You go to www.metpro.co.co/fasttalk.
[00:07:00] Trevor Connor: Now on with the show
[00:07:03] Chris Case: We got a spicy one today, or should we say a sugary one, a sweet one.
We’re talking carbohydrates today. Trevor, Julie, are you ready?
[00:07:12] Trevor Connor: Heck yeah. Are you spicy or sweet? Oh, pfft,
[00:07:14] Chris Case: I’m always sweet.
[00:07:15] Trevor Connor: Okay.
[00:07:16] Chris Case: You’re the spicy one.
[00:07:17] Trevor Connor: Yeah, I am spicy, I’ll admit.
[00:07:20] Chris Case: If you pay attention to endurance sports media, cycling, marathon running, ultra running, then you’ve almost undoubtedly read a story about how an elite athlete, Tadej or the guy that set the world record in the marathon, there’s countless examples of them shoving 120-plus grams of carbohydrates, ingesting that amount per hour day after day if it’s at the Tour de France, and some people are saying that’s why we’re seeing all the records broken.
That’s why they’re able to attack 100K from the finish line, do it day after day We wanna get into the science of whether that’s true or not today, and there is a new paper, it came out literally days ago
[00:08:12] Trevor Connor: Came out pretty recently. But our last Fast Chats, we were talking about that debate between Dr.
Burke and Dr. Noakes about high carbohydrate versus low carbohydrate diet, and then I was checking my feed, like, two days after we recorded that episode, and this came up in my feed. I went, “Oh, I wish we had this for that episode.”
[00:08:32] Chris Case: May 4th it was accepted, 2026, into the Journal of Sports Medicine.
[00:08:37] Trevor Connor: Yeah, so it’s just came out.
[00:08:39] Chris Case: Yeah. “Fueled or Fooled? Examining the Evidence and Mechanisms Behind Ultra-High Carbohydrate Intake in Endurance Athletes.” I apologize, Trevor, I know you love to read the titles. You can read the authors if you’d like. You
[00:08:52] Trevor Connor: can have that one. There were no- They didn’t have a lot of science terms in it- There was-
so I, I don’t get any street cred for that one.
[00:08:58] Chris Case: And there’s all words you can pronounce in there.
[00:09:00] Trevor Connor: I actually have a hard time with “Fooled.” “
[00:09:03] Chris Case: Fooled.”
[00:09:04] Trevor Connor: I do. Important to point out that the lead author and the final author were Dr. Dan Plews and Dr. Ed Coyle, both very well respected. They’ve done a lot of research together.
Both have published with Dr. Larson and with Dr. Seiler.
[00:09:21] Chris Case: Mm-hmm.
[00:09:21] Trevor Connor: And worth pointing out that Dr. Larson is, has been somebody that’s been against… I hope he doesn’t send me an angry email about this, but he has been more on the, “We don’t need the ultra-high carbohydrate,” that actually you can perform quite well on a high-fat diet.
[00:09:38] Chris Case: I think that is something not to dwell on, but to point out, which is that I think you might have just used the word “believe.” There’s a ton of evidence in the sports nutrition world, but there are camps. There’s one side- Mm-hmm … and there’s another side, and they look at the same evidence, and they fall in different places.
I just wanna point that out because that may come up a little bit in our- Yeah … discussion today.
[00:10:04] Trevor Connor: And there has been also a camp very much on the side of the ultra-high carbohydrate consumption.
[00:10:10] Chris Case: Mm-hmm.
[00:10:11] Trevor Connor: And we might have a, a bit of a debate about this, but I would say, at least until recently, the face of that camp has been Dr.
Asker Jeukendrup.
[00:10:20] Chris Case: Yeah.
[00:10:21] Trevor Connor: And, you know, I’ll point this out. We did an episode about the health impacts of sugar and high carbohydrate.
[00:10:27] Chris Case: Mm-hmm.
[00:10:27] Trevor Connor: And that was motivated by, on X, or I think it was Twitter at the time-
[00:10:32] Chris Case: Yeah …
[00:10:33] Trevor Connor: Dr. Jeukendrup posted Even masters athletes on their long, slow base rides should be consuming 120 grams per hour of carbohydrates.
[00:10:43] Chris Case: Yeah.
[00:10:44] Trevor Connor: And I just had to have a reaction to that. Like, we’re gonna have the discussion about elite athletes at the Tour de France, whether that’s appropriate.
[00:10:51] Chris Case: Mm-hmm.
[00:10:52] Trevor Connor: But it’s a different conversation about whether recreational masters athletes on a base ride-
[00:10:57] Chris Case: Right …
[00:10:57] Trevor Connor: should be consuming that much, and that’s part of what this paper’s about.
[00:11:00] Chris Case: Very different scenarios.
[00:11:02] Julie Young: I know we wanna talk about the paper first, but just to address Euchin Droop, I had recently listened to one of his current lectures, and he does seem to be walking that back in terms of that ultra high carbohydrate intake. And he noted that 2013 Gatorade study that was done in conjunction with Smith, where they felt the optimal carbohydrate intake topped out at 78 grams per hour.
And then v- basically concluded his lecture with 90 grams per hour seems appropriate for the masses. So he does seem to be walking it back a bit. And I was also surprised because he did mention Noakes’s paper and wasn’t totally dismissive of that paper.
[00:11:42] Trevor Connor: Well, what I also find interesting, and we’ll put in the show notes the link to the episode, it goes back a bit.
But we, a while, I was surprised how early on it was, we had Dr. Euchin Droop on the show to talk about gut training. Mm-hmm. And he really is the person behind this concept of if you don’t train your gut, you can only absorb a certain amount of carbohydrate per hour. But if you train it, you can a- absorb more.
And I looked back at that episode, and he was saying untrained, most people max around 60 grams. Right. And trained, you can get up to 90 grams. And so that’s why I was actually surprised that I was seeing him on Twitter saying 120
[00:12:20] Chris Case: grams. Mm-hmm. That is episode 150, so three- almost 300 episodes ago when you talked- Right
to him about the are there benefits to carbohydrate manipulation. That was the double-edged sword episode as we kind of call it internally. So check that out.
[00:12:36] Trevor Connor: Yep.
[00:12:37] Chris Case: But Trevor, why don’t you tell us a bit more about this paper, the intent and sort of capture the essence of the message here.
[00:12:48] Trevor Connor: So it’s a lengthy paper, and really important to point out at the top, you know, th- so this is in the journal Sports Medicine, a very good journal.
[00:12:55] Chris Case: Mm-hmm.
[00:12:55] Trevor Connor: But at the very top corner in a nice gray call-out-
[00:13:02] Chris Case: Yep …
[00:13:02] Trevor Connor: says, “Current opinion.”
[00:13:03] Chris Case: Mm-hmm.
[00:13:04] Trevor Connor: This is, even though it’s written like a review, this has been classified as an opinion piece, a- and you have to look at it that way.
[00:13:11] Chris Case: Right.
[00:13:12] Trevor Connor: So what they say is they are addressing this ultra high carbohydrate intake, that, as you said, it is on the rise.
There are a lot of influencers out there that are promoting this. You can see a lot of it on social media. You do see el- elite athletes, as you were pointing out, that are consuming very high quantities of carbohydrates when they’re training and racing, and they define it as 90 grams per hour or higher.
[00:13:39] Chris Case: That’s the definition in the technical sense of UHC, ultra high- Yep … carbohydrate.
[00:13:44] Trevor Connor: And they start by pointing out what you’re saying, that there’s this association with records getting broken. My immediate response is, yeah, but there’s also improvements in how we’re training. There’s improvements in gear.
[00:13:54] Chris Case: Yeah,
[00:13:54] Trevor Connor: there’s those, yeah. This is association. Those are associated as well, so how can you immediately say, “Well, it’s a high carbohydrate”?
[00:14:01] Chris Case: Mm-hmm.
[00:14:02] Trevor Connor: And they then go in to basically explain what I just said in very simple terms. They first looked at the three explanations behind ultra high carbohydrate consumption.
Important to point out, this is different from that Dr. Noakes and Dr. Burke debate that we were just covering about a very low carbohydrate versus a very high carbohydrate diet. They say in this review, yeah, carbohydrates are performance-enhancing.
[00:14:26] Chris Case: Mm-hmm.
[00:14:27] Trevor Connor: But what they’re questioning is 60 versus 90 versus 120.
[00:14:32] Chris Case: Is there a dosage effect here? Right. Is there a linear relationship between intake and performance?
[00:14:38] Trevor Connor: And what they’re ultimately we’re gonna get to as we summarize this paper, sorry to- Mm-hmm … spoil the ending, is they’re just not seeing a ton of evidence that 120 is better than 60 or that even 90 is potentially better than 60, and that is highly individual.
[00:14:53] Chris Case: And in some cases, they’re saying that there’s evidence to suggest that going over 90 is detrimental.
[00:14:59] Trevor Connor: Yeah, it has impacts on your gut.
[00:15:01] Chris Case: Yeah.
[00:15:01] Trevor Connor: They even at the end say, “And we have to look at health impacts.”
[00:15:04] Chris Case: Mm-hmm. Yes. ‘
[00:15:05] Trevor Connor: Cause there is evidence of that. So the three explanations that have been given for the ultra high carbohydrate consumption are glycogen sparing, that it prevents hypoglycemia, and it enhances carbohydrate oxidization.
[00:15:19] Chris Case: Mm-hmm.
[00:15:19] Trevor Connor: And they basically say the evidence for that is, is not great.
[00:15:24] Chris Case: Mm-hmm.
[00:15:25] Trevor Connor: First of all, they go, any evidence that you do see tends to be in the lab, and what they’re looking at is Studying whether you see any glycogen sparing, so taking muscle biopsies, does it spare glycogen in these athletes, things like that.
But they’re saying you’re seeing almost no studies looking at actual performance effects.
[00:15:44] Chris Case: Right.
[00:15:45] Trevor Connor: And when they do look at those studies, not a lot of great evidence. The one preventing hypoglycemia, Dr. Noakes addressed this in a lot of his recent studies and said, “Yeah, that’s really important.” But it takes a very small amount of carbohydrate- Mm-hmm
per hour. He, I think he said, was saying like 20 grams per hour.
[00:16:05] Julie Young: 10 grams. 10.
[00:16:06] Trevor Connor: 10, thank you.
[00:16:07] Chris Case: Yeah.
[00:16:07] Trevor Connor: Will get you there. Right. You don’t need 120 for that. So yes, you need some carbohydrates during training to prevent hypoglycemia. You don’t need 120 is basically what they’re saying.
[00:16:19] Chris Case: Mm-hmm.
[00:16:20] Trevor Connor: Glycogen sparing, they address that and basically say there isn’t a lot of evidence for that because what ends up happening, the idea was if you consume a lot of carbohydrate, your body’s going to favor the carbohydrates you’re consuming.
[00:16:34] Chris Case: The exogenous- Right … versus the endogenous. Endogenous.
[00:16:37] Trevor Connor: So exogenous being carbohydrates you consumed, endogenous being what’s in your body, so your glycogen.
[00:16:42] Chris Case: Yes.
[00:16:43] Trevor Connor: So you’re gonna spare endogenous carbohydrates. This is where you have to go back to the references ’cause they said there’s no evidence for that, and they had this paper that they cited, so I went and checked that paper, and that paper literally said, “We saw some evidence of glycogen sparing.”
[00:16:58] Chris Case: Mm-hmm.
[00:16:59] Trevor Connor: So not quite as black and white as they are making out to seem. But what they do point out, which I have seen in a lot of studies, is that when you start consuming a lot of carbohydrate, what you actually spare is fat.
[00:17:13] Chris Case: Mm-hmm.
[00:17:14] Trevor Connor: You start oxidizing less fat. Your body starts relying more on carbohydrates.
So yes, it’s gonna use the carbohydrates you consume But it’s also gonna use your glycogen, and so you’re gonna end up burning glycogen at a similar rate. And there’s some explanations behind that. There’s a, a older paper by Dr. Holly looking at transport of sugars or glucose to your cells-
[00:17:38] Angelo Poli: Mm-hmm …
[00:17:38] Trevor Connor: and pointing out it’s actually kinda difficult, and you have this nice glycogen storage in your cells.
So anytime you’re going pretty hard, your body’s still gonna favor that immediate store that’s in the cells versus trying to transport it from the blood.
[00:17:53] Chris Case: Yeah. I thought this was really interesting because it’s a suggestion that flips things on its head a bit in that we talk a lot about riding at paces and forcing your body to adapt to burning fat as a fuel, therefore saving the quick release glycogen for the efforts at the end.
What they’re saying is you put this much carbohydrate in your body, it basically s- your body says, “I don’t need fat at all. Just keep giving me carbohydrates, and I’ll just keep using it.” Yeah.
[00:18:25] Trevor Connor: And it’s still gonna preferentially use the glycogen stores in your cells because that’s an immediate source.
Mm-hmm.
[00:18:32] Chris Case: I
[00:18:33] Julie Young: mean, don’t you think, like, insulin is the main culprit here to all these cascading factors? Like, it’s gonna inhibit the lipolysis. It’s gonna facilitate that glycogen burning. It’s impossible to get out of that cycle. And I think, Chris, what you had mentioned, I had this real aha moment, you know, thinking, like, in training when we’re doing zone two, oh, we’re always doing fat burning.
Oh, that’s our fat burning zone. But it’s really what’s in your body. And I had a lecture with James Morton, and he’s the first one that was like this light bulb moment. He’s like, “No, it’s really if you eat a bunch of pancakes before you go out for a zone two ride, you’re burning those pancakes. You’re not burning fat.”
[00:19:10] Trevor Connor: One thing they did point out that I thought was really interesting and goes against what we used to be taught is that the thing that does actually impact how much of that exogenous carbohydrates you use is your glucose to fructose ratio.
[00:19:26] Chris Case: Mm-hmm. They hit that heavy. Yes.
[00:19:29] Trevor Connor: And that surprised me because traditional wisdom is we have a much better ability to transport glucose from the gut than fructose.
And so I think it was in a somewhat trained gut you can transport about 60 grams per hour of glucose, but only about 30 grams per hour of fructose. Mm-hmm. So the traditional wisdom was- Two to one … you should consume a two to one ratio But what they point out, and there’s a fair amount of evidence behind this, is actually one to one might be better.
[00:20:01] Chris Case: Mm-hmm.
[00:20:02] Trevor Connor: Because that seems to promote usage of that exogenous carbohydrate, particularly the fructose-
[00:20:09] Chris Case: Mm-hmm …
[00:20:09] Trevor Connor: for fuel. So that goes against the traditional wisdom.
[00:20:13] Chris Case: Right.
[00:20:14] Trevor Connor: Another thing that they point out that can be an issue with the ultra high carbohydrate consumption is that at high levels you see a decreased efficiency in carbohydrate oxidization, which is a really fancy way of saying if you consume too much, you just can’t use it all.
[00:20:34] Chris Case: Right.
[00:20:35] Trevor Connor: Because we have limits on how much we can absorb and use.
[00:20:38] Chris Case: And then the question becomes where does all that excess go?
[00:20:41] Trevor Connor: And they say that a lot of it sits in the gut. Yeah. And then you start having digestive issues. Exactly.
[00:20:45] Julie Young: So along those lines, just to follow up on that, Trevor, that Podlicar, if I’m pronouncing that right, in one of his studies he explained that efficiency drop, so with 90 grams per hour it was 86%, and then at 120 grams per hour it was 76%.
So that’s pretty significant.
[00:21:04] Angelo Poli: Mm-hmm.
[00:21:04] Trevor Connor: So basically what they’ve just done is address those three explanation for ultra high carbohydrate diet. So glycogen sparing. Mm-hmm. Doesn’t seem to really happen. Preventing hypoglycemia. You don’t need a lot of carbohydrate for that. And the enhanced carbohydrate oxidization, well, you see a decrease in efficiency.
[00:21:22] Chris Case: Yeah.
[00:21:22] Trevor Connor: And then they provide three potential explanations that are a little more unique for how this may improve efficiency.
[00:21:30] Chris Case: So just to point out and to be clear about this, this is an opinion piece. They’re seeing athletes perform well. They’re claiming that they’re having 120-plus grams, and they’re– and this group is saying, “We don’t see it in the evidence right now, but maybe there’s something to it.
Maybe the athletes are ahead of the scientific curve, so to speak, and they’re doing something that we just haven’t found evidence for. We’ll speculate as to why this might be working.”
[00:21:58] Trevor Connor: Yeah. Well, to that point, this is right out of the study. Again, when they looked at actual performance studies-
[00:22:05] Chris Case: Mm-hmm …
[00:22:05] Trevor Connor: they said, “Taken together, while carbohydrate ingestion consistently improves performance relative to placebo, clear evidence for a dose-response effect beyond relatively modest intakes, 30 to 90 grams per hour, is lacking.”
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[00:22:46] Trevor Connor: So I’ll quickly go through what they said are three possible explanations for why an ultra-high carbohydrate diet might be beneficial. And it’s interesting, one actually jumps on that fact that you start relying more on carbohydrates when you eat a lot of carbohydrates.
[00:23:01] Chris Case: Mm-hmm.
[00:23:02] Trevor Connor: We know that it requires less oxygen to produce the same amount of power from carbohydrates as it does from fat.
[00:23:09] Chris Case: That’s right.
[00:23:10] Trevor Connor: So if you’re relying more on carbohydrates, you’re going to be more efficient. Mm-hmm. You’re gonna need less oxygen. So it’s funny, for decades they were saying, “We need to become more reliant on fat, less reliant on carbohydrate.”
Now there’s this kind of shift of saying, “Actually, relying more on carbohydrates could be good ’cause you’re more efficient and, and this is gonna help performance.” I don’t know where I stand in that because you do see in elite athletes they rely on fat at much higher intensities.
[00:23:37] Angelo Poli: Mm-hmm.
[00:23:37] Julie Young: This kind of made me question my life.
Because, you know, in the lab we do these metabolic efficiency assessments, you know? And we really promote them as valuable and important, and it’s all about pushing that crossover point to the right. Yeah. And then this, this is now saying, oh, no, like, to be a really good performing elite athlete you push it to the left.
[00:23:56] Chris Case: Yeah, that’s-
[00:23:56] Julie Young: And so it’s just like, ugh, what the heck?
[00:24:00] Chris Case: Yeah, that’s kind of was my point earlier. This totally flips things around.
[00:24:04] Trevor Connor: Yeah. The way I interpret it is, so as you said, pushing it to the right means more reliance on fat at higher intensities.
[00:24:10] Chris Case: Until
[00:24:10] Trevor Connor: you see that curve. And, and left is carbohydrates.
I think what they’re saying is, overall, as you train and improve, you really want a big shift to the right.
[00:24:21] Chris Case: Mm-hmm.
[00:24:22] Trevor Connor: But when you’re going into that target race, you wanna move a little bit back to the left.
[00:24:26] Chris Case: Mm-hmm.
[00:24:27] Trevor Connor: Next potential explanation is it means you’re gonna be producing more lactate-
[00:24:33] Chris Case: Mm-hmm …
[00:24:34] Trevor Connor: as well, because lactate is an end product of carbohydrate metabolism.
We know that lactate is actually an important fuel-
[00:24:42] Chris Case: Mm-hmm …
[00:24:42] Trevor Connor: and it needs to be transported, because your fast-twitch muscle fibers produce a lot of it, but it’s your heart and your slow-twitch muscle fibers that can use it.
[00:24:50] Chris Case: Mm-hmm.
[00:24:50] Trevor Connor: So it’s gonna increase your lactate, but then those fibers are gonna take it up, those tissues are gonna take it up and use it for fuel.
But they do have the caveat saying, yeah, but really only elite athletes are good at taking up lactate and using it.
[00:25:03] Chris Case: Mm-hmm. Right. Why would that be?
[00:25:06] Trevor Connor: It’s those MCT1 and MCT4 transporters, which one transports lactate out, the other pulls lactate into the cells that can use it, and it takes a lot of training to really build up those transporters.
[00:25:18] Chris Case: Yeah.
[00:25:19] Julie Young: And then probably greater mitochondrial- Mm-hmm … volume as well- Mm-hmm … to be able to process it.
[00:25:24] Trevor Connor: Absolutely. Then final explanation was just a potential brain-derived mechanism. You know, they’ve done the studies where if people just rinse their mouth with carbohydrates-
[00:25:34] Chris Case: Mm-hmm …
[00:25:35] Trevor Connor: they actually, you’ll, during a time trial or a test, you’ll actually- Yeah
see an improved performance. So what they say is, “Oh, this carbohydrate is activating those sensors nonstop and just making you feel like you can go harder.”
[00:25:47] Chris Case: All interesting theories about what could be happening. E- each one of them makes me go, “Oh, God,” in a way, because it just seems like we’re encouraging people to consume so much sugar that they become reliant on it, and then they get…
They might do it on the bike, and then they get off the bike, and their body’s craving it, and they don’t have the willpower to not shove it in their mouths, and that doesn’t seem like a very good scenario in the long term. And I don’t know what it’s going to do to elite athletes who are stressing their bodies for maybe just a decade, but with such massive volumes of workload and nutritional stress through inflammatory sugars.
You know, it sounds scary to me.
[00:26:35] Trevor Connor: Yeah.
[00:26:36] Julie Young: But do you think, Chris, that the elites are doing it during those competitive periods? But Burke had said this, too, r- right? One of her rebuttals in the debate was like, “We got a- away a long time ago from these blanket prescriptions of massive carb intake, like, all the time,” and they’re really…
They advocate that periodized nutrition-
[00:26:57] Chris Case: Yeah …
[00:26:58] Julie Young: strategy. I think there’s certain times where these elites are, like, they’re pulling back, like, maybe, I don’t know when it would be, off-season, you know, de- depending on the type of training they’re doing, pulling back on that carb intake. I think that’s still a strategy in play.
Again, I think this was something Burke really brought out in her rebuttal. It’s like we’re not professing, like, high carb all the time. Mm-hmm. They really are focused on that periodized approach.
[00:27:22] Chris Case: I think at the very top of sport, when a team has a chef And they know what should be served off the bike, and they know what should be served on the bike.
Those are optimized in a way, and those are better balanced. It’s the amateurs who have this knack for following what the pros do that think they should have it on the bike, and then they go home, and they don’t have a chef at home to cook for them, and then they just have- Yeah … a giant pizza or they… I don’t know.
It’s speculative, and maybe it’s prejudiced in some ways, but I just feel like it, it leads people to form really bad habits in some ways that have potentially serious consequences.
[00:28:05] Trevor Connor: Yeah.
[00:28:06] Chris Case: I think that to be a professional athlete these days, you can’t take the Jan Ullrich approach and gain 20 pounds or 30 pounds in the off-season ’cause you go and drink beer for a couple months and then try to burn it off through coffee rides.
That doesn’t work anymore. I think you have to be pretty much turned on and optimized almost 365 days a year. So the elites are in one category here, and the amateurs, I feel like, possibly fall into a very different category in a lot of ways.
[00:28:38] Trevor Connor: Well, I’ll actually take it a step further and say even in elites you have to be careful.
So I’m looking at a 2016 study that Dr. Jeukendrup was an author on.
[00:28:47] Chris Case: Mm-hmm.
[00:28:48] Trevor Connor: And this study was addressing the fact, you know, the argument at the time, we knew that sugar consumption, high sugar consumption had really negative impacts on inflammation, and the argument was always, yeah, but if you’re consuming the sugar during high-intensity training or during a race, you don’t see those negative impacts, and you need that sugar to get that maximal power.
[00:29:12] Chris Case: Mm-hmm.
[00:29:12] Trevor Connor: So this was literally a study to test that, where they took fairly elite cyclists, 13 male cyclists. I don’t think they were world-class, but they were trained-
[00:29:22] Chris Case: Mm-hmm …
[00:29:23] Trevor Connor: fairly strong cyclists, and had them consume a high amount of carbohydrate During testing and looked at what impact did it have on inflammation and what impact did it have on their maximal power.
And what they found is even during interval training, there was a negative impact on inflammation that you don’t wanna see, and it didn’t really help maximal power. So I’m reading right out of their conclusion here. “Since neither maximal power output nor immunity were better maintained with a high carbohydrate intake, and increases in fat oxidation were lower, it could be argued that ingesting a moderate, so approximately twenty grams per hour, carbohydrate dose during short-term interval training may be more advantageous than a higher carbohydrate dose, at least when athletes already have a high daily intake of dietary carbohydrate.”
[00:30:14] Chris Case: Mm.
[00:30:14] Trevor Connor: This all leads us back to the Field or Fooled paper and their conclusions, and they had two really interesting points in their conclusion. And Julie, you touched on one with the individualization.
[00:30:28] Julie Young: We’re talking about so much nuance here in terms of context, an athlete’s events and goals, and then the athlete in terms of their training status and how it’s so individual in terms of how much an athlete can tolerate and then utilize in terms of the carbohydrate.
And as I’d mentioned, I haven’t seen– Like the performance nutritionists that I’ve worked with, I haven’t noticed them pushing a hundred and twenty grams to the masses. I’ve seen them kinda cap out at ninety grams. But even within that, it’s always troubled me that the nutrition prescriptions on a daily basis are based on grams per kilogram.
So you’re doing a moderate day, so it’s five to seven grams per kilogram of carb. High day, eight to twelve grams per kilogram. But then when y-you hop on the bike, it becomes real absolute. Mm-hmm. That’s always troubled me. And so when I look at athletes in TrainingPeaks and use their kilojoules, and I will look at two different athletes doing the exact same workout.
Obviously, they have different thresholds, so if I compare like a male to like a small female, using the kilojoules to determine carbohydrate requirements, those requirements are so different And then, like it could be for the female, it’s like 55 grams per kilogram, and for the, the male it’s 90 grams per kilogram for that same workout.
And I think another illustration of this, and we spoke about this in our last Thinking episode, and Chris, you had mentioned the London Marathon. Mm-hmm. And the two runners that broke the two-hour mark. The one that won was at like 120 grams per hour, and the second place, who was just 11 seconds behind first, was at 60 grams per hour.
And some people may say, “Oh my gosh, he would’ve done so much better if he pushed 120.” But we you know, it’s hard to say, but I just think that speaks to the individuality of it. And then back to the elites, they just have developed such unique physiology and metabolic infrastructure that allows them to process these fuels efficiently.
[00:32:31] Trevor Connor: And that’s basically what they said in the conclusions is you look at the studies done and how much carbohydrate people can oxidize in an hour. So oxidization is the scientific term for use.
[00:32:42] Chris Case: Mm-hmm.
[00:32:43] Trevor Connor: And they showed at the very, very high end, about 114 grams per hour.
[00:32:48] Chris Case: Mm-hmm.
[00:32:49] Trevor Connor: But they were also seeing people that were only 60, 70, 80 grams per hour.
Mm-hmm. So it, it’s very individual, and they make the point that it’s probably a very small number of elites that could actually oxidize 120 grams.
[00:33:03] Chris Case: Yeah. And I think the other side of this, and not to harp on it, but they also mentioned the study that looked at what this was doing to the specific athletes, and they were showing that they were entering into a pre-diabetic-
[00:33:19] Angelo Poli: Mm-hmm
[00:33:19] Chris Case: state. It was reversible. I can’t remember if it was 30 days post they looked- Yeah … but it was reversible. But the fact that you’re ingesting this much carbohydrate and then theoretically using it doesn’t necessarily protect you from having the health consequences. It’s one thing if you’re sitting on the couch and you’re having 120 grams per hour.
That logically seems like a really bad thing to do. But if you’re having 120 grams and you’re exercising at a intense rate, it still doesn’t protect you just because you’re using it- Yeah … from having these health consequences.
[00:33:56] Trevor Connor: And again, that is a long-held belief in the science that when you’re exercising, insulin response shuts down.
So you can consume all this sugar, and you’re not gonna develop diabetes. You’re not gonna have all these negative health effects. As you said, there is some truth to that. It is better than consuming the same amount of carbohydrates sitting on the couch. But basically, what they’re saying is, if you think this is bulletproof and fully protects you, think again.
[00:34:23] Chris Case: Yeah, exactly.
[00:34:25] Julie Young: Well, I think where they really brought that out, Chris, is this, the gut training practice-
[00:34:28] Chris Case: Mm-hmm …
[00:34:29] Julie Young: where that just was really, I mean, kind of a recipe for disaster in terms of leading to pre-diabetes.
[00:34:36] Trevor Connor: Yeah, yeah.
[00:34:36] Chris Case: The other aspect here, too, not to shift gears and not to call anybody out, I think that GCN does a lot of interesting work, and they’re taking on some of these subject matters that are trending and popular, and they’re not the only media outlet that has jumped on the, “Oh my God, somebody’s…”
It’s almost like a record. Like, “Oh my God, they had 150 grams per hour.”
[00:34:59] Trevor Connor: Yeah. Oh, you told me this story yesterday, and it’s horrifying.
[00:35:02] Chris Case: One of their hosts go on and meet with Tim Podlakar, one of the authors we’ve already mentioned in this study, and they went to Exeter University, where he works, and they had him do a two-and-a-half-hour ride, and he basically said, “Put me on the 120-gram carb diet for this two-and-a-half-hour ride.
I wanna see if I can do it.” And this guy is 6’6″, 6’8″, something like that. He’s a very big dude. He has been a very high-caliber cyclist in the past. And lo and behold, he has a lot of gut issues. He barely finishes. He feels completely horrible. But the really interesting thing to me, and this is the… Again, I’m not trying to pick on them.
I’m just saying that I think this is the message that gets sent out there is He got his results back, his results being how much he burned per hour of the 120 grams he consumed, and he was only at 46 grams per hour. Mm. And he was very disappointed in that number, as if it were a FTP number that was really low, but it- that’s totally missing the
[00:36:07] Trevor Connor: point.
That’s why it’s saying it’s horrifying that they’re- this is now becoming a competition.
[00:36:10] Chris Case: It is. That’s what- Yes … I feel like it is. He put himself in the guinea pig role, and that’s cool and interesting. Good for him for doing that. Others are like, “Look at this athlete.” It’s almost like setting records in terms of ingestion, and I feel like that’s wildly inappropriate.
It’s not really impressive. What it is, is expensive if you’re paying for all that sugar, and perhaps unnecessary, completely unnecessary, as we’ve just talked about based on the science.
[00:36:40] Trevor Connor: Yep. So this is right out of the Fueled or Fooled. Mm-hmm. Say that again. Talking about the Fueled or Fooled. I told you I struggle with those.
Fueled or Fooled. You’re gonna make me say that a lot, aren’t you? Talking about the importance of the individualization, and they, so they say, I’m just reading here, “By adjusting intake on the basis of individual glucose oxidization rates, athletes were able to achieve similar carbohydrate utilization while consuming 28% less-
[00:37:10] Chris Case: Mm-hmm
[00:37:11] Trevor Connor: and simultaneously reducing both the perceived exertion and gastrointestinal fullness and discomfort.” Basically saying, if you optimize it, you can actually consume less and perform better.
[00:37:22] Chris Case: That’s right.
[00:37:23] Julie Young: And better for your health.
[00:37:24] Trevor Connor: Yep.
[00:37:24] Chris Case: The tricky part for a lot of people is knowing what that number is, because they don’t- They go
[00:37:28] Trevor Connor: to a lab
[00:37:29] Chris Case: they can’t go to a lab. The three of us have that luxury. We have ample opportunity to understand lots of metrics about our bodies because of labs that we’re live near or friends that we have that are physiologists, whatever the case may be. Most people, I would probably say, don’t have that luxury- No … to do that test, to understand what that figure is.
[00:37:47] Trevor Connor: But I think where we can start is it is very unlikely that you are one of those rare individuals that can actually oxidize 120 grams per hour.
[00:37:58] Chris Case: Mm-hmm.
[00:37:58] Trevor Connor: You are s- gonna be somewhat lower, and this isn’t a contest. This is about performance, and what they’re saying is getting to what is optimal for you is where you’re gonna perform the best.
And so I think it takes some experimentation.
[00:38:10] Chris Case: Yeah. And I think that’s probably a general rule that if you’re a bigger person- Mm-hmm … then you will burn more, but that isn’t a hard and fast rule either, as proven in, in some ways proven. It’s a strong word, but as indicated by this 6’6″ athlete who says eats like a horse and all this stuff, but his number was 46, which is a reasonably average number, I would say, to use per hour.
[00:38:38] Julie Young: And Chris, I think that’s true, as I, I gave the example of the two different athletes doing the same- Mm-hmm … workout. Mm-hmm. The other side of that is a young female mountain biker who I coach, I looked at one of her one-hour mountain bike races, and she was at 90 grams per hour for that race.
[00:38:56] Chris Case: Yep.
[00:38:57] Trevor Connor: So let’s kind of wrap up here by talking about what we think are the overall conclusions here.
And I would say, if I had to sum it up, they basically said this is niche.
[00:39:08] Chris Case: Mm-hmm.
[00:39:08] Trevor Connor: There’s a small number of elite athletes that can consume that amount, and they, I think they even made the argument that it’s probably what makes somebody like Tade so amazing. ’cause he can consume that amount. But it’s not recommended for most of us, and at this point, the science behind it, the evidence for…
Not carbohydrate consumption. Again, they say you need a certain amount. I think they kind of recommend 60 to 90 at the top end-
[00:39:40] Chris Case: Mm-hmm …
[00:39:41] Trevor Connor: to perform at your best. But this ultra high, the evidence just isn’t there.
[00:39:45] Chris Case: Yeah. I think there’s another aspect that we haven’t really touched upon, which is they speculate, Tade being a good example, any world tour rider who’s doing the Tour de France day after day, it’s not the 120 grams they need per hour within the ride, but it helps with recovery so they can do it repeatedly day after day, which is a scenario that there’s 198 riders at the Tour de France in the male field and similar amount in the female field.
The rest of the world doesn’t do that. Yeah. They don’t need recovery for 21 straight days, 23 straight days.
[00:40:28] Trevor Connor: That was a good point. They did mention in the study that a high consumption of carbohydrates during exercise speeds your recovery.
[00:40:35] Chris Case: Yes.
[00:40:36] Julie Young: I think it’s also about the energy availability, and then the other piece we didn’t bring out is that unique role that carbohydrate plays as a signaling molecule for the neuroendocrine system.
And I think with all of this, I always get concerned ’cause the pendulum seems to swing so hard one way or the other So like when I was racing, carbohydrates were, oh gosh, like avoid at all costs. Mm. You know? And now the pendulum has swung back hard the other way, but I think just finding that balanced approach and just remembering there are reasons for doing things.
You wanna maintain this balance where you can get that optimal oxidation and recovery, and then take care of your immune system, your endocrine system, your bones, for example, like which carbohydrate play an important role, and then also your health, not overdoing it, leaning towards that pre-diabetic state.
So I think just really thinking for yourself, like where are you, what is the goal of what you’re doing, and I think that’s the problem, is just there’s been so much influence, whether it’s the social media or it’s the actual sport nutrition industry that’s pushing this message.
[00:41:46] Chris Case: Yeah. We didn’t mention the sports nutrition brands who feel like they have cracked the nut in terms of how to get carbohydrates at high- Mm-hmm
quantities into the body without causing GI distress and a- all these other things, and that’s their business. Their business is to have people consume as much as possible in some ways, so they’re a bit biased, but they’re definitely an influence here. Their marketing is all over the place. People fall victim, if you will, to, to marketing sometimes.
[00:42:20] Trevor Connor: Well, I think it’s an important point, and sorry, I know some of our listeners get annoyed when I bring this up, and I keep harping on it. But it’s important to remember while you get all sorts of great marketing about how amazingly sophisticated these sports nutrition products are, and it’s even in the title, sports nutrition, we have a Rocket Fizz over on Pearl Street.
[00:42:41] Chris Case: Mm-hmm.
[00:42:41] Trevor Connor: They don’t call it candy nutrition. It’s just a candy shop.
[00:42:46] Chris Case: Yeah.
[00:42:46] Trevor Connor: And I will point this out again and again that these products, while absolutely there is evidence that this is performance-enhancing, that you need a certain amount if you want to perform at your best, and this paper is making that point that it’s probably less than where we have gotten to, but these products that you are consuming that are designed for this, they are candy.
[00:43:11] Chris Case: Mm-hmm.
[00:43:12] Trevor Connor: They are just sugar with some electrolytes and water or a gel that’s mostly just sugar.
[00:43:18] Chris Case: Mm-hmm.
[00:43:19] Trevor Connor: And you have to keep that in mind and remember your focuses because nobody is saying candy is healthy. And I just, you know, at the end of this, want to remind everybody As you said, if you’re sitting on the couch drinking these sports nutrition drinks and taking gels, you’re just eating candy.
[00:43:36] Chris Case: Mm-hmm. A lot of it, yeah. And it’s just not as if that number means that you’re fitter. Right. It’s not as if the more you consume, the faster you’ll go. Like we said, there’s a number out there that’s individual to you. It’s very unlikely that it’s above 90 grams per hour. And beyond the number that’s right for you, which could be a mystery to a lot of people, but beyond that number, you’re…
it’s a waste. It’s doing harm, not good.
[00:44:08] Julie Young: But I also think, Chris, that we probably don’t have to be perfect with this.
[00:44:12] Chris Case: No.
[00:44:13] Julie Young: You know what I mean? Like, we don’t have to get that absolute number.
[00:44:16] Chris Case: No.
[00:44:16] Julie Young: I think if we get pretty close, that’s probably good.
[00:44:19] Chris Case: From your time as an elite athlete when you were saying that carbohydrates were sort of looked down upon to the time right now when people have gone a bit crazy and the pendulum has swung to the other side, there’s been a lot of new evidence to suggest that, yes, carbohydrates are necessary for high performance, and 60 to 90 is a lot higher than what was being recommended 20 years ago, right?
So the pendulum- Yeah … has swung possibly too far, and it… but it’s gonna come back to potentially a place that’s higher than it used to be.
[00:44:55] Trevor Connor: Yeah. You know, and going back to that not everybody can be tested, finding your optimal is not, don’t do a bunch of math and go, “I want to be that 120- Right … or the 90 plus, so I’m gonna keep eating it until I get there.”
I would say there are some good guidelines you can use to find what’s right for you. If you are eating very little, and you’re finding you’re bonking towards the end of a race or a hard ride, you’re feeling a little hypoglycemic, you’re probably consuming too little, and next time you need to increase your rate of consumption.
If you’re starting to feel bloated, if you’re getting some gastric distress, that goes back to what they were calling the reduced carbohydrate efficiency, which is just- Mm-hmm … a fancy way of saying you’re not consuming it all, you’re not using it all, it’s sitting in your gut and it’s fermenting and it’s making you uncomfortable.
Mm-hmm. So you’re consuming too much.
[00:45:50] Chris Case: Mm-hmm.
[00:45:51] Trevor Connor: So you wanna find that happy middle place of I’m not having any GDI distress, but I’m also not bonking.
[00:45:59] Chris Case: That’s right. That was another episode of Fast Talk. Subscribe to Fast Talk wherever you prefer to find your favorite podcast. Don’t forget, we’re now on YouTube.
Give us a like and a subscribe there, and help us grow our reach. As always, remember that the thoughts and opinions expressed on Fast Talk are those of the individual. Join us on social media @fasttalklabs. For access to our endurance sports content and continuing education for coaches, head to fasttalklabs.com.
For Trevor Connor and Julie Young, I’m Chris Case. Thanks for listening.
