Why Exogenous Ketones? (Sponsored)

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Transcript: Why Exogenous Ketones? (Sponsored)

Season 10, Episode 12  | April 17, 2025

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Not for me. Welcome to another episode of lifetime talks. I’m David Freeman and I’m Jamie Martin, and in this sponsored episode of Life Time Talks is brought to you by Kenetik, the energy drink that taps into nature’s ultimate super fuel, ketones. It powers your cells with crash free energy for enhanced focus and clarity, faster recovery, and long-term cellular health.

And with us today to talk about the roles of ketones in optimal health is Dr. Elizabeth Yurth. Dr. Yurth is the co-founder and chief medical officer of Boulder Longevity Institute, where she’s been providing tomorrow’s medicine today to her clients since 2006. Along with her 30 years as a practicing orthopedist specializing in sports and spine medicine, Dr. Yurth has made it her mission to learn and share the latest scientific research on how to truly heal the body at a cellular level.

She is a fellowship trained in anti-aging, regenerative, and cellular medicine and has completed 500-plus hours of training focused on longevity, nutrition, epigenetics, bioidentical hormone replacement therapy, regenerative peptide treatments, and regenerative orthopedic procedures. Dr. Yurth continues to serve as a thought leader in cellular medicine, speaking at longevity events across the world and teaching others through her position as a founding faculty member for Seed Scientific Research and Performance Institute. Dr. Yurth, welcome back to Life Time Talks.

Thank you, guys. It’s good to see you again.

Alright. So Dr Yurth, let’s get right into it. Ketones — why do they matter when it comes to optimal health?

So let’s start with — because maybe some of your listeners don’t actually even know what a ketone is. I think some people are familiar with well, I go — I go into a ketogenic diet, but what is actually a ketone? So ketone is really just this chemical compound. It’s a carbon atom that’s double-bonded to an oxygen. And in terms of why they’re so important to health and why you think about them in your exercise routines is because there are alternate source of fuel instead of sugar.

So when we burn fat — so let’s say once you’re doing an event, and you’ve used up all of your glucose stores, what do you do? At that point, you start burning fat. And when you burn fat instead of sugar, you make ketones. So ketones are the energy source that’s provided when you start burning fat. So that happens if you’re fasting or if you’re eating a very low carbohydrate diet, where there’s not glucose being fed to your cells, then your cells need to depend on something else. So they start burning fat and making their own ketones. Intense exercise will do that.

And just again, if you’re going a long time without eating — so let’s say I’ve gone 24 hours without eating, my body has used up all its glucose stores, and it’s going to start making ketones. So they’re really important. And our body actually makes two ketones when we’re in this fasted state or exercise state, where we’re no longer burning carbohydrates because we’ve used them all up. We make what’s called beta hydroxybutyrate, which is the main one I want you guys to focus on because that’s the primary fuel source for things like our brain.

Remember, when we’ve exhausted our energy sources, the main thing we need to keep alive is our brains. Our body goes to ketones because they’re really readily accessible to the brain. And the other one is what’s called acetoacetate, and that’s really just a precursor molecule that converts into acetone. And that’s why if you’ve ever noticed, if somebody’s been fasting or eating a really high protein, low carb diet, sometimes they have that weird breath. So that’s actually what you’re smelling on their breath is acetone.
So why are these molecules so great? Why is it so much better to use ketones over glucose? It’s really not that one fuel source is that much better. It’s an alternate fuel source. And our body really relies on this metabolic flexibility. It would like to have the ability to switch between utilizing glucose and utilizing fat as an energy store. We can go back and forth. But the cool thing about ketones and why they’re so valuable to overall health is because if you think about what is — when we’re eating carbohydrates, when we’re eating food, why are we making glucose, right? Or why are we utilizing glucose to make energy, to make ATP?

So we eat glucose. It goes through glycolysis and then oxidative phosphorylation, and it makes energy it makes ATP. So for each molecule of glucose, you make 30 ATP. That’s your money. That’s your cash. That’s how you spend money to, so your car keeps going. Well, the nice thing about ketones is they directly convert to ATP. So they basically don’t have to go through this same glycolysis process. They can go right into oxidative phosphorylation. So they can just directly make ATP.

So they require a whole lot less oxygen per ATP molecule. So I’m no longer having to rely on a whole lot of oxygen to go through glycolysis to make ATP. So by skipping that whole energy consuming step of glycolysis, I get a lot more rapid utilizable energy source. So think about ketones as almost 30% more efficient than glucose to keep your body going. So that’s what’s really so cool about them.

That’s awesome. Is there a certain — I mean, I’m thinking about this from — I recently ran a marathon, and I needed a lot of carbohydrates and glucose to help fuel that. But I’m thinking about that rapid fire hit type workouts that David does all the time and that I should be doing more of. But talk a little bit about when — does that help there, the ketones? Because they’re readily available. They can be utilized in that moment more quickly.

So really when you’re doing fast burst exercise, the ketones are probably less valuable than when you are running your marathon. A lot of times we’ll do with our endurance athletes is we’ll have them — because at some point, you’re just events. Even when you’re sucking down your glucose, it’s nice to be able to convert to ketones because you can actually utilize those. So when we were — I was working at the Leadville 100, which is a really intense race. And we would have the athletes start doing some ketones mixed with their water maybe at the 20-mile, 30-mile mark because they need another source besides glucose. They’re going to rapidly go through their glucose. So ketones could provide that energy source to them.

So when you’re doing this HIIT training, probably you don’t have to rely on the ketones as much. But will they still be utilized? Well, yeah. They are going to give you a really fast energy source. So it’s a little bit like why fasted cardio is so good — why you burn fat faster when you’re doing fasted cardio. Because if you don’t have any carbs on board when you’re doing cardio, you’re going to go right to fat burning store. So yes, you are right that we can get a more instant energy source.

But what they’re really nice for if you’re just your general athlete, and you’re not doing endurance events, is recovery. So in that recovery period, what if I can make a whole lot of energy? I’m going to actually be able to build muscle better. I’m going to be able to recover faster. I’m not going to get as much lactic acidosis. I’m not getting as sore afterwards. So what we really like to use the ketones, and there’s a lot of research on them in the recovery phase after you’ve done like heavy weight training or HIIT training, that you can use them in the 30 minutes to an hour post the exercise, and you get much better results from your exercise.

Nice.

I love that. And I want to unpack that more. A lot of times when coaching a lot of my athletes, I speak to energy systems. And as we all know, you spoke to it — the oxidative glycolytic ATP. When we now know they’re all working at the same time, it’s just one might be a little bit more present than the other. The part that I love that you just said is — Jamie, you threw the HIIT question in there. And Dr, what you ended up responding with is readily available. So obviously, if we’re now doing more high intense workouts, which everybody loves because they associate a great workout to what they’re feeling. Or laid out on the ground, sweating and all these other things up. I did a great workout, but the reality is they probably used a readily available, the carbs, just because it’s the preferred energy source in that high intensity piece.
And what happens is — and I want you to confirm this for us — when we’re training so much in that high intensity, what the body now tends to do is it starts — I call it the way you practice is the way your body plays. So if you’re working out for a high intense workout for 30-plus minutes, then when your body is at rest, it naturally wants to probably utilize more of the carbs, right? So if we can teach our body how to use the primary — not the preferred energy source but the primary energy source of fat in training our body in that way. And I’m going to come back full circle to the ketones here. But I just I think emphasizing that we automatically think harder is better. So if you can break down why it’s so important to have that contrast of understanding more of that zone 2 or fat utilization while you’re training is important in this space.

And this is where — that’s your own ketones that are going to be produced. So if I’m fasted when I do my cardio, then I’m going to use my own ketones. So a little different than when I actually am giving exogenous ketones — when I’m drinking a ketone drink, for instance. Then I’m giving exogenous ketones to help support my energy. So will you tap less into the fat stores? Actually not. You’re actually going to be just burning fat a little bit faster, even if you’re giving the ketones exogenously. Your body actually will be supported in this utilizing fat instead of muscle to work.

But you’re right, David, that metabolic flexibility is the key. We actually need our bodies to always be able to go back and forth between these sources. And so if we can give ketones and have glucose on board, that’s probably the best of both worlds. And one of the ways you can do that, honestly, is by instead of having zero carbs — that’s why a lot of people don’t tolerate a zero-carb diet. —having some carbs on board. So you’re still keeping that glycolytic ability, but then giving some ketones, so I don’t have to be in a fasted state or a fat — this state where I have to rely — I’m still utilizing some glucose stores, but I can tap into this other energy source by giving ketones exogenously.

So what we found is that you actually don’t need these naturally produced ketones for the benefits. That you can actually — when you take ketones and you just drink them, like during your workout or after your workout, you can reach this activation threshold more consistently of enhanced athletic performance, enhanced metabolic flexibility, reduced inflammation much more rapidly than if you were relying on your own ketosis to do it. So it’s interesting that when you’re talking about that metabolic flexibility, the ideal way to do that is honestly to supply your body with an alternate source, instead of relying on your own body to make it.

Then your body keeps that ability to do glycolysis and ketosis at the same time. Whereas normally we can’t do that so well. And that’s the problem when people are doing these just very, very low carb diets or zero carb diets. Is that you actually start to over time — that will work for a while. So I have no problem with people doing that short term. But ultimately, your body will actually get less and less adaptable at utilizing other energy sources. So now when you go back and you add any carbs, and you’re going to have problems. So if you can keep a little bit of a lower carb diet and then add exogenous ketones in, you get the best of both worlds.

Right. What are those exogenous ketones? I mean, we think about how are they produced in order for us to be able to take them and ingest them.

So it’s different ways that exogenous ketones are made. And there’s a lot of different companies out there that make exogenous ketones. Back probably a few years ago, there was really one. Now, there’s a half dozen on the market. So when you look at what our body produces with ketones, it produces about 75% of the beta hydroxybutyrate, which is the key molecule that your brain needs and your muscle needs. And then it makes about 20%, 25% acetoacetate, which is a waste molecule that’s just breathed out as acetone. So we know that beta hydroxybutyrate is the chemical compound that we need.

So we can actually just synthesize beta hydroxybutyrate. And the interesting thing is that we really — when you look at companies that are making beta hydroxybutyrate. And I’m not going to be an — I’m not an expert in how you synthesize beta hydroxybutyrate, but a lot of companies actually just make beta hydroxybutyrate. And the unfortunate thing is that this comes in two mirror images. It comes in what’s called a D and a L isomer. It’s like a right hand and a left hand.

So if I just make beta hydroxybutyrate, about half of it is not utilizable. So what you really only want is the D beta hydroxybutyrate. That’s what my body makes. That’s a little bit more difficult to do. And there are some companies that take the time to separate those two molecules out and just use the D beta hydroxybutyrate. There’s also companies that make — so that’s what’s called a ketone ester. Other companies use what are called ketone salts. So they attach the beta hydroxybutyrate to a salt molecule.
The problem with that is that you are getting a lot of salt — either sodium or magnesium. So you’re getting way too much of a salt, which actually reduces the body’s ability to absorb it. So it’s just not going to work as well when I’m giving this big salt load along with it. So those are the cheapest out there. But you really want ketone esters, and you really want a ketone ester that’s taken the time to only use the beta hydroxybutyrate D isomer, and that’s hard to find.

So that’s really when you’re looking at these ketones. And that’s why, Kenetik, who you guys are sponsoring this is my go to. It’s because they’ve taken the time to make just this one isomer, which we continue to consider bioidentical ketones. It’s identical to the ketones you’re making. It’s the D isomer. And it’s this ester that can be directly utilized to your brain and your muscles.

Is it clearly labeled? Like you said, there’s a growing body of products that are available in this space. Is there an easy way to tell if a product is the D isomer ester version?

So the ketone salts are pretty easy to figure out because they will say if you read them, ketone salts. Between the ketone ester products, no. That’s not so easy to figure out. You really have to go back into the company and look at how they’re synthesizing it to see. And there’s not — I will tell you, there’s not a lot of products out there that actually do that. I can think of two.

So honestly, Kenetik is one of them. I’m not going to say the other one, but there’s basically two products that actually do that. But what Kenetik did to make this even a more utilizable source is they actually separated out this beta hydroxybutyrate. So when you’re making an ester, it has this sort of bond. And they actually broke the bond, and that happens when we digest ketone esters anyway. But by breaking the bond one of the interesting things was it made the taste so much better.

The big problem with early ketones — honestly, I’ve done a lot of ketones — is they are almost unpalatable. They taste like gasoline. It’s horrendous. So basically, you would suck these down. You’d do it because you’re like, OK, I have to this is good for me, blah, blah blah, but it literally is taking a shot of gasoline. That’s what it tastes like. Kenetik actually solved that problem by simply breaking this ester bond before digestion. So pre-hydrolysis of this ester bond before digestion, number one, made it faster absorbed by the GI tract, more efficient uptake, and much better tasting.

It’s very interesting that you actually lost some of that — because the taste is so bad. They did a study with some of these really bad tasting ketone esters, and they raised cortisol enough to increase glucose. So you’re actually kind of doing a counter effect because this taste was so bad and so stressful to a lot of people’s brains, they actually induced a cortisol response. Whereas actually like these, honestly, they taste really good. And for you guys, listeners, I don’t have financial incentive in this company — I drink like three of these a day because they keep you going, but they taste really good.

Yeah. And David and I have both tried them, and I have had love testing the different flavors and seeing which ones were my favorite, so it’s great. Yeah, David. Where are you at?

No, I was going to go into I think it’s important to understanding what would be optimal when taking a Kenetik — is it pre? Is it during? Is it post? To get that absorption. To get the best benefit from it. What would you say within that? So if you look at the research on ketones, most of it is for recovery. So if I go on research base, I’m going to tell you probably, optimally, if you’re doing the type of workouts we’re doing, David, where it’s more HIIT training and weight training, probably — what I do is I drink one of these right after my workout because that’s going to replenish my — it’s going to rapidly get energy to my muscles and energy to my brain. I’m going recover faster. I’m going to feel really good. I’m able to train harder the next day.

So that’s where most of the research has been done. There is more and more research coming up on, are these going to be helpful as well when we are actually exercising? So can you put a little bit in while you’re exercising? Certainly. For endurance athletes, if you’re doing long runs, yes, because being able to have those ketone sources available so you can add — instead of just the cans, they make this very condensed form that you can add a little bit to water, like add a capsule to water, so it looks like this.
And you can add a capful or two to your water bottle and then start drinking that to give yourself another energy source, so when you’re out of glucose — or that you can use both sources at the same time. So you gain this very rapid energy source while you’re going through glycolysis. So I think that the research is coming up more on whether these are going to be beneficial to enhance your strength training and enhance your HIIT training.

Right now, I will tell you that I use them primarily in recovery for most of my athletes, except my endurance athletes. Well, I will have them do it during exercise. And ideally, it looks like probably using about 20 grams — anywhere from 12 to 20 grams post-exercise is probably the best dosing of the ketones. So a pretty good dose. You can. So there is some research, especially in people who have injuries for instance, or people who have — let’s say your people who are recovering from COVID, or virus, or who have a lot of — David, you probably work with these athletes.

Their endurance is — like everything you try and do with them, they just don’t have any endurance. And I consider those a little bit like my sick people, my MS patients, people like that. Because when you look at the long COVIDers, and fibromyalgia people, these are all people who need a lot more cell energy. So I will have those people dose 20 grams of ketones about 30 to 60 minutes prior to exercise, and then you’ll actually peak that ketone level when you’re trying to train them.

So for you, David, most people, it’s just hard to train. They’re just like, I just can’t even get out of bed. How do you want me to lift that weight? Tell them to do about 30 to 60 minutes prior to the session, and that seems to then peak around time when they’re going to get in there working with you, and they’re going to optimize some energy available for exercise. So we do that a lot when people are recovering from injuries with physical therapy. We’ll have them do it 30 to 60 minutes before exercise.

So I think that we are going to, as research goes on about ketones, get better and better with how we can utilize these most appropriately. But I would say right now before exercise for your people who need it, after exercise for almost everybody, and during exercise for your endurance athletes.

Got it. That’s an awesome breakdown for everybody. So we’ve talked a lot about the fitness benefits of ketones, but I want to talk about some of the other health benefits because I know you’ve outlined for us, things like neurological and cognitive benefits, immune system modulation, and inflammation. So talk a little bit about some of those other health effects that ketones can influence.

Yeah, honestly, these to me might be the coolest thing about ketones. And is that they are super anti-inflammatory. It’s one of the biggest things I’ve seen. So we do — I still do a lot of orthopedic medicine. And my athletes will be like my knees feel so much better when I have them on ketones. And that’s because ketones naturally suppress something called an NLRP3 inflammasome. So this is a inflammation that’s produced a lot in people with autoimmune conditions, but arthritis is — any inflammatory disease processes, they’re producing this inflammasomes. This inflammasome keys in all of these bad cytokines that are keeping inflammation high.

So the ketones directly suppress that. So you can take your people who have this injuries or arthritis, and you can suppress the inflammatory response that will sometimes be induced during exercise. Because you remember exercise does induce a pro-inflammatory response. And we want a little bit of a pro-inflammatory response. That’s how we build muscle, but we don’t want an over inflammatory response. So what can be done is the ketones will naturally suppress — and they’ve homeostatic. They won’t overly suppress it, but they will naturally suppress some of this overactive immune response.

So it’s really one of the really cool things about. It also is they’re really good for the gut. So they will help repair gut. So they’ll protect the gut, the intestinal barrier, integrity of the gut. Improve this mucus strengthening proteins that are in the gut, so people who have leaky gut, things like that. And they’re antioxidants. So basically, you get this production of these antioxidant enzymes. And I don’t know if you tell your patients this, David, but we don’t like to take a lot of antioxidants when we’re exercising hard. We need oxidative stress. So the cool thing about ketones is they’re not going to blunt this appropriate oxidative stress reaction that exercise induces. They’re going to keep it from going sky high and creating problems.

I mean, it just sounds like the secret sauce right here as far as this just would benefit any and everybody. But I got to ask the question just because I know people are curious about it. Is it something that would not benefit some people or should not be taking? They probably need to get checked before they start taking anything that has ketones in it.

So really there’s really nobody — I mean, I have some really, really, really sick people on ketones. So there’s a lot of questions, for instance, in your diabetics. Should diabetics — because you think about diabetics getting ketoacidosis, right? Their glucose drops too much, and they go into ketoacidosis. Well, the nice thing about ketones is they don’t create ketoacidosis because they aren’t the acetoacetate. So they’re not creating that acid molecule that happens when we’ve utilized all our glucose stores.

So that’s one of the reasons you don’t get a sore and things like that. So they’re really actually safe, even in your diabetic patients, because you don’t feel like, oh, this is going to drop blood sugar. I’m going to go to ketoacidosis. No, because they don’t have the acid part. They are just beta hydroxybutyrate. So honestly, ketone salts, yes, there’s a problem with them because they can disrupt sodium loads, things like that, but there’s people who just can’t drink things or hate the taste or whatever. There’s really nobody who I don’t use these in. Nobody.

Interesting.

That’s awesome. Yeah.

Cool. Well, Doctor Yurth, we’ve taken up so much of your time already. What else would you want to make sure people know about ketones and maybe even about Kenetik as a brand? Because I do think, they are sponsoring this episode and I love knowing that they’ve figured out the flavor side of things. If that’s something hindering people from using this, that’s great, but anything else you want to add?
Yeah. I mean, that is huge. It’s that flavor piece. I mean, I actually enjoy drinking these. Honestly, I used to do ketones because they are so good for me, but it really was like, are you suck them down? You get this horrible flavor in your mouth, so they are really good. I also think that this company — and one of the things I always like is companies that are doing something for the right purpose. And for instance, one of the guys who developed this company has a daughter, who has a very rare genetic disorder and relies on ketones to actually survive.

So the company actually developed things in the right way. They’re working with us as physicians to help a lot of people who have MS, cancers, things like that we are — long fatigue, long COVID because — so I like a company that also is actually trying to do the right thing, right? I mean, I love the sports performance aspect, but in my world, I need these super high dose ketones because I have people who are really sick and need a lot of ketones. And they’ve worked with me to help develop these. So I also just like that this is a really good company.

That’s awesome. Great. Well, I want to make sure people know where they can find you. We so appreciate you coming on. So if people want to learn more from Dr. Yurth, you can visit boulderlongevity.com. And also follow Dr. Yurth @dryurth and @boulderlongevityinstitute on Instagram. And to learn more about Kenetik, people can visit www.drinkkenetik — that’s K-E-N-E-T-I-K — .com. So Dr. Yurth, thank you so much for spending some time with us.

I appreciate you guys sharing this information.
Absolutely.

Thanks so much.

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