Is The Ketogenic Diet Good For Athletes

Is The Ketogenic Diet Good For Endurance Athletes? EndurElite Chief Endurance Officer Matt Mosman and Chief Science Officer Jordan Joy discuss the pros and cons of this diet for runners, cyclists, OCR, And other endurance athletes?

Some of the ideas and concepts discussed in the video are articulated in greater detail and with greater specificity here.

Video Transcription:

Is Keto Diet Good For Runners, Cyclists, OCR, And Other Endurance Athletes?

Matt: Good morning, Family of Fast. Matt Mosman, the Chief Endurance Officer over at EndurElite. Today, we're going to be talking about a hot topic, and that is the ketogenic diet. More specifically, we're going to discuss what the ketogenic diet is, what happens from a metabolic perspective with the ketogenic diet, if it's a good fit for endurance athletes, and we're gonna cover some other random topics about the ketogenic diet.

Now, I'm no ketogenic expert, but I had an idea this morning where I could find one. So I headed down to the gym, and I looked for the biggest, baddest bro dad. And they're really, really easy to spot. They have really shaggy beards, broad shoulders, and meaty arms. And I found this guy right here. And I was like, "Dude, I will give you a five-pound tub of protein, if you tell me a little bit about the ketogenic diet." And to these guys, it's, like, pure gold. 

But all kidding aside, this is your first chance to meet my partner at EndurElite and the EndurElite Chief Science Officer, Jordan Joy. Now, Jordan Joy has his Ph.D. in nutrition, super smart guy and a ketogenic expert. So the information you're gonna hear from him is gonna be true. It's gonna be accurate. And it's not gonna be the usual bro science bullshit you usually hear about the ketogenic diet. So without further ado, let's just hop into it. All right, Jordan, explain to us what the ketogenic diet is.

What Is The Ketogenic Diet?

Jordan: Little-known fact, I'm actually Matt's bodyguard, but he does pay me in protein. So that part is accurate. Now, the ketogenic diet, it's any diet that actually induces ketosis or elevates blood ketones through a nutritional process that's not starvation, which would be the other kind of ketosis. And then the third kind of ketosis would be metabolic ketoacidosis. And all these are very distinct things. So when we talk about a ketogenic diet, we're talking about nutritional ketosis, which is high fat, low carbohydrate, moderate protein.

What Food Is Included On A Ketogenic Diet?

Matt: So what kind of foods do people on a ketogenic diet typically eat, or what's some standard foods?

Jordan: Bacon.

Matt: Bacon. Love me some bacon.

Jordan: Some of the most popular foods, bacon, really meats in general, dairy. We still eat vegetables. That's a little bit of a myth that vegetables are not eaten. Avocados are a big deal. I recommend to everybody that starts a ketogenic diet to eat an avocado every day just for the fiber content. It's the easiest way to get it. Coconuts, nuts. I eat a ton of peanut butter. Yeah, that about covers it.

What Is The Macro-Nutrient Breakdown Of A Ketogenic Diet?

Matt: Very nice. So what does the macro-nutrient breakdown look on a ketogenic diet from your fats to carbohydrates to protein?

Jordan: Okay. So within the nutritional ketogenic realm, we're talking about nutritional ketosis. We are looking to elevate blood ketones by manipulating our diet in a certain way. So there's different types of ketogenic diet that you could be consuming. And that could be the therapeutic ketogenic diet or just, kind of, the origins of this way of eating, where we're inducing ketosis for a nutritional purpose that helps to treat some sort of disease, most popularly, epilepsy. The most accepted use of the diet is for treatment of epilepsy seizures. It's been more commonly accepted for treating diabetes, less so for heart disease but that's emerging, cancer, for certain types of cancer. And in these types of diets, we're looking at, like, really, really high fact in some cases and sometimes 90%, 95%. And it, kinda, depends on the individual. So when we're talking about epilepsy, for example, somebody might stave off their seizures with an 80%, 85% fat diet with 5%, 10%, 15% protein.
For people that it's harder to treat, they may be on a super high fat, pretty low protein diet and almost no carbohydrate whatsoever. And then when you're talking about the average person, we're talking about at least 70% fat and 20% to 25% calories as protein and 5% to 10% as carbohydrate. And we're gonna talk about something today that is a little bit more liberal. For an athlete's ketogenic diet, which is at this current stage, a little bit poorly defined, but athletes need a little bit more carbohydrate. And you can actually maintain ketosis eating 200, 300 grams of carbs a day. So we'll talk about that a little bit later in the video.

Matt: Awesome. Okay. So basically, the breakdown is 70% fat, 20% protein, and 10% carb in a nutshell or pretty close to it.

Jordan: Yes, usually 70-25-10, or sorry, 70-20-10 or 70-25-5, or sometimes even 80-15-5, common.

Metabolism On A Ketogenic Diet

Matt: Cool. So the main thing is high fat, low carb, simply put. So let's talk about a little bit what happens from the metabolic aspect with the ketogenic diet. Now, as endurance athletes, a lot of us are on a higher carbohydrate diet, and we get our energy from glucose and glycogen, but when you're on a ketogenic diet, things happen a little bit differently. The ketogenic diet relies more on free fatty acids to produce energy. So, explain, kinda, what happens from a metabolic perspective on the ketogenic diet that's specific to, like, endurance athlete energy demands.

Jordan: Yeah. When we are taught energy metabolism, we're always taught that it's glycolysis. And that's true when it's anaerobic. And that's what, you know, when you feel lactic acid that's anaerobic metabolism, end product's lactic acid. When we go through aerobic metabolism, which is the most common, most prevalent type of metabolism for endurance-based exercise long-duration events, you can still derive energy form carbohydrates through first the anaerobic glycolytic pathway. And then it goes into what's called the Krebs cycle. When you are talking about ketogenic metabolism we're almost exclusively talking about aerobic metabolism to get in to the Krebs cycle and produce energy. Now, when we're going through anaerobic metabolism, we generate 4 ATP. And when we're going through aerobic metabolism, we're generating more like 34, 36 ATP.

Matt: Got you. Okay. So what are the main fuel sources? What happens when the free fatty acids are broken down before they go into the Krebs cycle? There's two basically ketone cells that are made, correct?

Jordan: Mm-hmm. So when we're going through the aerobic metabolism, there's an entry point that you go through, and it's called acetyl-CoA. And you get that from either anaerobic or aerobic routes. When we're having fat come in, we're taking these big long chains of fats several carbons long, 16, 18, 20 carbons, and they come in to...they want to become acetyl-CoA in order to get into this cycle.

What happens, we have a buildup of what are called ketones, beta-hydroxybutyrate or acetoacetate. What happens when they're coming into the cycle is there's not enough room for them to get in. We can't generate enough acetyl-CoA from these fats. So we end up with an accumulation of these two-carbon to four-carbon molecules. And then they get released from the mitochondria for release from the cell. And they can enter the bloodstream because that's when they're small enough to actually exit the cell.

Does A Ketogenic Diet Work Well For High Intensity Endurance Exercise?

Matt: Got you. So a couple of points here, and this is a question I ask, Jordan, all the time, where do you think that threshold is where your body is able to utilize the fats from the ketogenic diet before it starts to shift to more anaerobic glycolysis, which can only use carbohydrates? I mean, what's, kind of, that inflection point? Does it differ between people? And then how do you accommodate for that? Like, if you're on a ketogenic diet and say you're gonna go do some interval training and it's gonna be, you know, 85% to 90% of your max heart rate, obviously, your body's not gonna be able to burn fat. It wants to do carbs or glucose, glycogen. So what happens then, when you're on a ketogenic diet?

Jordan: You feel flat and a little bit lethargic, like you're out of energy pretty much. I'm sure we've all felt that way before, but when we're talking about, like, the spectrum of exercise, we have very short events. So if you're doing just, like, a 40-meter sprint, if you just do one of those on the ketogenic diet, you probably won't feel any different because you have enough glycogen stored up. You can still access it. As long as you're exercising regularly, you're still accessing glycogen. You don't really forget how to use it. And then when you're in a little bit longer, like, 3 minutes or 30 seconds to 2 minutes, you're gonna...when you're doing intervals, for example, you'll definitely feel fatigued. And then even during the longer events, I think, even up to, like, marathon distance, if you're a very high-level athlete, I think you would feel impeded on a strict ketogenic diet, not the athlete's ketogenic diet, which is yet to be explored thoroughly, but then after a marathon a distance I think is when you would start to possibly experience benefits of a ketogenic diet.

Is A Ketogenic Diet Beneficial For Ultra Endurance Athletes

Matt: So it sounds like the ketogenic diet is for endurance athletes. You know, most of the people in the EndurElite Family of Fast are, kinda, long duration endurance athletes. So they're racing for more than, like, 30 minutes and, you know, up to 6, 7, 8 hours. So it sounds like to me, and I'm gonna make a couple points here, the ketogenic diet may be more beneficial the longer the event and maybe the lower intensity type events. Is that correct in my thinking?

Jordan: That is correct.

Matt: So what does a person need to do say if they're doing a 5K, that's pretty short and intense, they're on a ketogenic diet, what can they do to make sure they have the energy to run their fastest?

Jordan: Yeah. So 5K, if you're running at a high level, you're gonna be under 20 minutes, for sure. So if you just have enough carbohydrate before that event, I think that you would actually be okay.

Can You Have Carbs On A Ketogenic Diet

Matt: And I think that's where a lot of people get confused is, like, on a ketogenic diet, like, you don't allow any carbs, but in this case, what Jordan is talking about, it's pretty beneficial, like, just to load up on carbs before a 5K, before you go to the race. And then you can go back to a higher fat...well, stick with the regular diet. Just introduce carbs before a race, correct?

Jordan: Yeah. And there's actually, like, a... When we talk about carbohydrate periodization, we have an article up on EndurElite right now talks about this. If you supply...and these people are not on a ketogenic diet, but if you supply carbohydrate before high-intensity events, and then restrict it for low-intensity long duration events, you actually have greater metabolic adaptation. So a ketogenic diet, I think, it's just a tool, all right? A ketogenic diet is a tool to adapt your metabolism to different types of stress.

So even if you are a very high-level competitive athlete, you're gonna be carbohydrate-based throughout the season, maybe during the off-season, you go ketogenic for a couple months. And you just, kind of, force your metabolism to adapt for a little bit, it's not going to impact your performance negatively during the season because you're not on that type of diet, but perhaps you have greater capacity for fat oxidation or you can use fats a little bit higher intensity, generate a little bit less lactic acid, make your fuel sources last a little bit longer, and overall just become a better athlete.

Ketogenic Vs. A High Carb Diet

Matt: Makes perfect sense. So let's, kind of, move onto the next topic. And I want to make one point here. On a high carbohydrate diet as an endurance athlete, your body has about anywhere from 400 to 1,000 grams of glycogen stored in the muscle and depending on what type of athlete you are, which you'll draw on during these longer events, and that supplies the energy, but it's a limited supply. And that's why you have to replace through a carbohydrate supplementation during exercise to keep blood glucose levels elevated to have that energy to keep on going. So what's really interesting is, like, with the ketogenic diet and being able to utilize fats, it almost represents an unlimited energy source. Would you agree with that?

Jordan: Yeah. It's virtually unlimited. You can store, even a lean person, 70,000 calories. So you're probably not gonna run out.

Matt: Yep. So a lot more potential for energy. You'd have an energy [inaudible 00:11:56] from the ketogenic diet, but with limitations depending on the duration and intensity. So let's go back to that topic. As far as an endurance athlete being on a ketogenic diet, where do you see it being the most beneficial? Like, what type of events? I mean, I know we, kinda, touched on it before, but let's just discuss this real quick, who it might be best for as an endurance athlete and who it may not be best for?

Jordan: Absolutely best for the ultra-endurance athlete, the longer-than-marathon distance, especially when you're talking about these very long events that are six plus hours long, would definitely reap the most benefit. And I think for, like, track athletes, I don't think there's really a whole lot of benefit because they're purely anaerobic almost all the time.

Matt: Makes perfect sense. So that, kinda, leads me to my next question. What was my next question? So that, kinda, leads me to my next question. And it's, kind of, a tricky one. Do you think a ketogenic diet is superior to a high-carbohydrate diet for endurance athletes? And let me just say this. There's thousands of studies on high carbohydrates in endurance athletes. And I would say, like, research studies that examine the ketogenic diet in endurance athletes are pretty sparse compared to the latter or the former, excuse me.

Jordan: Yeah. So I think one of the problems with the current state of the research on ketogenic diets is that we haven't examined it in the right context. So we've always taken the therapeutic type of approach and then applied it to athletics. And that doesn't work. So I think that being in ketosis as a healthy individual is a little bit overrated. And I say that as somebody who's been consuming a ketogenic-ish diet for the better part of the last five years. I say that as an athlete, obviously, not an endurance athlete, but, like, I've gone up to...I've gone over 200 grams a day.

And I regularly eat over 100 grams a day carbohydrates. And I'm able to maintain ketosis at least most of the time. And I've actually adapted. How I define my own diet, I say I'm on a low carbohydrate diet that is sometimes ketogenic. So I think for, in terms of which one is better for the general endurance athlete, I think if you're competitive, again, it's a tool. It's something that we can use to modify our metabolism a little bit just to increase our metabolic flexibility. So even if it's something you're not comfortable with doing all the time, it's something that can be used when you're not competitive to increase your ability to oxidize fats, okay?

Now, when we're talking about, if you were to want to use it during the season, I think that eating carbohydrate is an important part of that. And I don't think that you should be concerned with being in ketosis all the time. So if you have a high-intensity event or a high-intensity training session, I think you should eat carbohydrates because what you want from that session is performance. What you want in your race is performance. You don't want to be bogged down at all, but again, this is, kind of, just a more extreme model of that carbohydrate periodization. So instead of being high carb all the time and just kind of, like, temporally changing when and what types of carbohydrate you eat, it's just, like, a more extreme variation of that where you're more often low carb than you are high carb. And sometimes you drift into ketosis.

Matt: Got you. So I think the main point here is, like, most people think, like, ketogenic diet, you have, like, little to no carbs, but Jordan's basically saying that it's okay to have some carbs on the ketogenic diet as it relates, I mean, to performance. Like I said before, the ketogenic diet by itself, high-intensity efforts. If you're not eating carbs, your performance may suffer, but if you introduce a little, you know... I mean, how much would you say, like, on a daily basis would be appropriate? I know it's gonna differ from individual to individual.

Jordan: Definitely, activity dependent. So our great friend, Eric Serrano, says, "Carbohydrates are activity dependent." And that's very much true from a metabolic perspective. Carbohydrates supply energy, and they don't do a whole lot else in the body. So if you are at a higher volume, like I said, I am a power lifter so my reliance on carbohydrates is actually very limited because even when I'm weight training, I'm not getting into anaerobic ranges most of the time. I'm usually using an ATP system. So I just have ATP available. I use it. I don't really need to generate it from carbohydrate that often.

So as an endurance athlete, obviously, you have a little bit of smaller body type, but I think even going up to 100 plus grams a day, even on my off days, I have 80 grams of net carbs. And that's another point that we can talk about. I think you'd be pretty comfortably able to maintain some degree of ketosis and fat adaptation. On the topic of net carbohydrates, that's subtracting fiber, subtracting sugar, alcohol because we're only considering the carbohydrates that are actually going to directly contribute to our ATP generation.

When Should You Eat Carbs On A Ketogenic Diet?

Matt: Makes sense. Now, athletes on a ketogenic diet, should they consume the majority of their carbs right before their endurance workout do you think on a daily basis?

Jordan: It's best used before and during, possibly after, depending on if you're gonna have another training session or you have very long sessions on back-to-back days, but before or during or both would be the best time. And I should have mentioned this in the last segment. If you are trying to adapt onto a ketogenic diet, if you've never done it before, you absolutely need to go through four weeks of ketogenic dieting before you start to try trading carbohydrates. What happens when you are not in ketosis and you haven't been in ketosis probably for your entire life, unless you went through a period where you weren't eating, when you try to adapt, you need to go full in. You can't just, kind of, like, pussyfoot around and [crosstalk 00:17:51].

Matt: Pussyfoot.

Jordan: You're not gonna get into it. You're just gonna end up being in limbo, and you're gonna be miserable. You're gonna be somewhere between not adapting and, "Give me some carbohydrates now before I cut your head off."

Matt: That's very true. And from personal experience, which I'll get into in a second, like, when I tried ketosis for the first time, I felt like complete ass for the first three to four weeks. Zero energy, headache, grumpy, angry. I just wanted to eat all the fucking carbs in the world, but I didn't do it. I didn't do it. So let's address one more point, and then we'll wrap it up.

Is A Ketogenic Diet Healthy?

A lot of people have asked about the health consequences of being on the ketogenic diet. Like, a lot of people think, like, you know, high fat, you know. And that's the fricking devil. Like, it's gonna cause coronary arteries and all these other negative health consequences. So let's discuss, like, ketogenic diet and effects on health.

Jordan: Yeah. So the ketogenic diet's not gonna kill you. And we actually, as humans, we're very adaptable. So even just beyond that fact, fat's an essential nutrient. Carbohydrates are not. And I like to make that point. I also like to say that fruits are vegetables with added sugar. People don't like that, but no, you'll see your insulin will go down. Your blood glucose goes down. You have much less risk of diabetes on a ketogenic diet. Your blood lipids is, kinda... sometimes, they get weird. So for the first six months, you might see increases, but they tend to normalize after that.

You might see increases in the LDL fraction of your cholesterol, but you'll see big decreases in your triglycerides. That's typical. And as far as, like, other health markers, people report, like, better mental clarity. There are some studies in rats that show greater longevity, none of those in humans yet. But overall, no negative health consequences. And just another point, people who have kind of shifted over to the ketogenic lifestyle, so you're obviously very familiar with the carbohydrate-based individuals, and I'm very familiar with the ketogenic-based individuals, they think fat's evil. And we think on this side that carbs are evil. And really, they're not evil at all. They're just tools to get us to a certain point.

Matt: And we all know there is one thing that's evil, and that's sugar, but we'll talk about that later, just kidding. All right, so we're gonna wrap this up. I'm gonna tell you my personal experience on the ketogenic diet right now. Jordan convinced me to do it. I don't know, about two years ago. And he fully proclaims that I didn't do it right, but I know I did it right. And I'm gonna tell you one thing, like, I'm, kinda, up in the air about the ketogenic diet quite honestly.

Like, when I was on it, you know, the long slow stuff I felt absolutely amazing, but when I got into, like, my higher intensity part, I'm training this season, you know, I fell flat on my face. And that may be my mistake too honestly as far as not carb loading on the frontend before doing my harder workouts, but for the time being, I'm a little bit of both. I, kinda, do what Jordan does. I, kinda, have a little bit more of a metabolic flexibility. Some days I'll have higher fat, lower carbohydrates, and I'll periodize it, and that seems to work pretty well. Jordan, anything else you want to add?

Jordan: Well, just on that note, even the recommendations are starting to soften. And we see people, nutritionist- dieticians going above that 35% in calories from fat limit.

Matt: Very nice. Well, there you have it, Family of Fast. That is everything you need to know about the ketogenic diet as an endurance athlete. If you have a buddy that's currently on a keto diet or is thinking about it, please share this video with them. If you want other videos like this on endurance training, nutrition, and supplementation, subscribe to the EndurElite YouTube channel or head on over to the EndurElite blog at Get social with us on Instagram and the Facebook training and nutrition club page. And until next time...

Together: Stay fueled, stay focused, stay fast.

Matt: And stay informed.


Also in Fueling Fast Blog

best joint supplement for endurance athletes
Joint Elite - A Closer Look At THE Premier Joint Support Supplement

science at endurelite
Science Is The Standard At EndurElite

what is cluster dextrin?
Cluster Dextrin- A Superior Carbohydrate For Superior Performance