Research Review! LCHF and Ketogenic Diets For Endurance Athletes with Stephanie Howe PhD | Koopcast Episode 53

trail and ultra runners what is going on what's happening welcome to another episode of the KoopCast as always i'm your host coach Jason Koop i'm glad everybody's with me today because this one is a good one we have another research breakdown and is all about ketogenic diets and high fat low carbohydrate diets and their impact on endurance performance and in order to cut through a lot of the clutter with the research i brought on the podcast today somebody who's way smarter than me in this area and that's one of our coaches stephanie howe PhD we take a look at the past the present and the future of the research in this area and try to make it make sense for all of the athletes out there in order to guide your decisions and although the conclusions that the past the present and the future research has come to all seems to be in alignment they keep coming to the same answers time and time again this is still a confusing area of research and one that's riddled with nuance and something that is honestly underappreciated particularly in the ultra marathon world so much so and then we discuss this during the podcast that a lot of athletes and a lot of coaches out there are relying on anecdote in order to guide their practice and to determine what is best

for them going forward we try to break through a lot of that in a very logical sensical way and then at the very end we discuss what it would take to change our minds what would it take for us to say okay we want to think about this a little bit differently than we do today which i always think is an open minded and very healthy way to think about a lot of these things so here we go let's get right into it here's my conversation with ketogenic and high fat low carbohydrate diets with one of our coaches stephanie howe so you want to get into this yeah i'm excited to talk about it i was about to say i knew you'd be stoked when we're when i presented the subject matter to you i'm gonna i'm gonna rewind a little bit because i am gonna as as as i alluded to this morning i'm gonna let you take over a lot of this but i want to rewind a little bit to provide some some context for the listeners because i know like a lot of a lot of coaches and a lot of runners out there they don't have the entire context of history when it has to do with when it has to do with looking at nutrition interventions and in many cases we've looked at the same interventions over the course of 20 years and sometimes found the same conclusion sometimes found different conclusions and other times find like more kind of like nuance to it and i think this is one of those cases when we're looking at ketogenic and low carbohydrate diets and their way to

potentially impact um endurance performance and you know i've i've been coaching for nearly 20 years and whenever the subject comes up i always go back to the i always go back to the point that this is the third time this is like the third round that i've really seen this strategy start to come to light and to like catch some attention in the space and so it's not new i guess is the first thing we've we've looked at this and sports scientists have kind of looked at this for years and just in my just in my coaching career this is right around the third time and relative to this paper there have been three other papers or sorry this is the third paper that the same author has published that that has revisited this area so the paper we're going to talk about was published in 2020 and the title of it is ketogenic low carbohydrate high fat diet the future of elite endurance sport i feel like i should emphasize that differently the future of elite endurance sport question mark because the question mark that's the key part of that title there is there is a question mark at the end of it is it's commentary that was written by louise burke very esteemed uh sports scientist from the australian institute for sport has been doing it for many years probably one of the most esteemed sports scientists in the world particularly in the area of nutrition and particularly in this in this area but this is the the third piece of

commentary that she has produced in this area over the last 16 years the first one was in 2006 and the title of it is fat out fat adaptation for athletic performance the nail in the coffin question mark question mark question mark kind of coming out our titles are brilliant the titles are great because they're like they're they're provocative which science needs a little bit more of that some of it tends to be a little bit dry but so that was the first one is produced in 2006 and once again kind of i'm lining up with my this is the third time i've seen it time frame that was the first one and then the second one has a kind of a equally provocative title it's re-examining high fat diets for sports performance did we call the nail in the coffin in quotes too soon question mark so all three of these titles have some sort of question mark in it and louise's point with the commentary that she's providing is to try to answer that question right and i think all too often when coaches and athletes and like uh lay literature get a hold of scientific commentary a lot of emphasis is put on the title or a lot of interpretation i guess is put onto the title the title and just reading the abstract and maybe the conclusions 100 100 100 so we're specifically going to go over the last iteration or

the most recent iteration of this which is ketogenic low carbohydrate high fat diet the future of elite endurance sport question mark and the as i alluded to this is commentary this is louise luis burke's commentary on the state of the science on this particular topic it's not a intervention study it's not original research or anything like that she's taking and that she's she's taking all of the research that is that has existed over the course of all the years in particular the most recent ones and coming up with an opinion on it and trying to summarize it right yeah this is a really good review article of all of the literature on this topic and i've heard louise speak about the low carbohydrate high high fat diet and she is she works out of the australian institute of sport and works with a lot of olympians and is really invested in dietary interventions for enhancing performance and so this talk that i heard her give she said she was really she actually wanted to find a benefit in this low carbohydrate high fat but study after study they had done in their lab they just couldn't find a performance benefit and so she's just kind of you know been the the leader in and keeping us on track with this um but she's very invested in performance and what's best for the athlete so like you said she's an incredible um breath of knowledge

and um in sports nutrition one of the leaders for sure yeah i think there's a couple of other um poignant remarks or poignant frames of reference that we need to keep in mind when we start to discuss this commentary is the first one we already mentioned is that this is research and analysis of other research that's been done over years but the second one is is with because it's coming out of the australian institute for sport which is part of their olympic program their focus is primarily on the olympic events and in this context it's the olympic endurance events which for for for an endurance perspective that's the 5k the 10k the marathon and race walking which there's a lot of research on on race walking now since we have primarily an ultra marathon audience there are certain like leaps of faith and certain things that we don't know certain extensions of the research that may or may not be valid but when we're talking about the the commentary that that we're going to give some review on uh louise louise burke's particular point of reference is for those olympic sports primarily although there's some small commentary that i'm sure that we're going to get into as it directly applies to uh to ultra marathon athletes so so that's the context so steph this is your world this is your wheelhouse you take it away from there what what are like the key findings

what are the key summary points on this particular piece of commentary yeah so this this review is really well done and um louise kind of breaks down every study that has looked at any intervention in low carbohydrate high fat including ketogenic and non-ketogenic and really talks about first all of the misconceptions in this area because that's really a big part of it um is not knowing the definition and the actual definition of a ketogenic low carbohydrate high fat diet is less than 50 grams per day of carbohydrate and about 75 to 80 percent of energy coming from fat so that's kind of the first piece of like okay so there's a lot of misinformation out there just even about what this diet is and then two most of the purported benefits actually come from social media there's not too many studies that have addressed this issue it's mostly coming from just the spread of people an n of one or just writing a lay article or tweeting something that are promoting um the benefits of um low carbohydrate high fat so she really does a good job of kind of setting the stage and then she breaks down every study that has looked at you know different athletes different interventions and this is where kind of the the nuance comes in looking at the

methods and trying to compare apples to oranges between an observational study um a really rigorous um controlled study and just looking at what did they actually measure how long did they measure so it's like when you start reading it it's really like wow we don't know there's not a lot of consistency between studies and so when you when you look at that it's it's hard to really even say that we know very much about the outcomes um but in her review and i just went through this morning to like and i circled she has a column that says performance benefit and in every single one there is no benefit in performance when the subjects consumed either a self-selected or a short-term or a medium or long-term low carbohydrate high fat diet there was no improvements in performance and to me that's kind of the bottom line because when we're talking about eating a certain way to improve performance for endurance athletes that's what we care about we don't really care about are they better fat oxidators which they are but does that translate into performance and so that's the number one key takeaway from this review article what's what's interesting is is you know i painted like this kind of broad history and we could even go back to the mid 80s when some of the stuff was originally studied

there's this there's this dichotomy where we actually were sports scientists and athletes have looked at it and have tried it and do have anecdotal evidence from these types of nutrition interventions for years but yet as you were just mentioning the actual scientific conclusions are inconsistent and like fewer and farther in between than you would think for something that has received as much attention as it is received right right and one of my favorite quotes from louise is turning controversy into conclusion is not science um you know you when you think about what you learn in the lab and through a research study versus real life application it's not black and white so yeah there are people who have changed their eating patterns and i'm just going to go ahead and say they're probably eating better they're probably paying more attention to what they're eating and most of their improvements come because they maybe could stand to lose some weight and they they improve their body composition and that turns into improved performance but not necessarily for the reasons that they claim that it's the low carbohydrate it's not that it's that they were reduced their energy intake and they improve their performance through that those means so so so the the the bottom line nickel version of this is the answer to the original

question is a low carbohydrate high fat diet the future of elite endurance sports the answer that is no based on this review no yeah and i i think it you know there's been like we'll get into this but louise did a repeat study on her findings first first time there's been a repeat study um and she found the same exact results so as far as we know this is this is not the future of elite endurance sport yeah i like i like the way that you couch that though is with as far as we know because something could change two years five years ten years from now and we know something different or the intervention is tweaked or whatever that makes this whole conclusion different right and that's part of being really um when you're when you are a researcher or into science you're open to changes you're open to things as we progress and we learn more and that makes you a better i guess scientist not that you're like i see one way and one way only right well so we're going to come back to two points right we're going to come back to supernova one and supernova two and then we're also going to come back to the what would it take to change your mind question which we're always open-minded and yeah i think it's i think it's poignant to to to think about those things years down the line where yeah something might actually come along we might think about things differently but before we jump you know before we start to jump to that i think it it's an it's a too simplistic of an answer or maybe it's not but it's a really

simplistic answer just to say no it's not it's not the future at least as we know it today it's not the future but there are a lot of purported mechanisms for a low carbohydrate high fat diet being superior in endurance performance and i think that this i think that this commentary starts to bring to light what all of those purported mechanisms or supposed mechanisms are how they've been tested and then what the results of those tests actually are so maybe we can first kind of move through all of those different this is why it might actually work because that was one of the questions that lorice originally started with back in the mid-2000s is like okay this is how it could actually work let's test for it so what is this what does this review paper say in terms of that yeah so just even taking a step back to define just the two substrates that are used during endurance exercise so carbohydrate and fat we don't use protein as a substrate so carbohydrate and fat are the two fuels that our body uses and it's not like a light switch where we use one or the other we use them varying degrees depending on the intensity the higher the intensity the more carbohydrate the lower the intensity the more fat and there's a crossover point that happens where we start to use exponentially more carbohydrate and at that point is usually around depending on the person 50 to 60 percent

of their max so if you think about race intensity you're usually going to be above that crossover point where you're starting to use more carbohydrate so i think that's an important point to make is you're always using some of both unless you're at really high intensity um exercise which like at your max basically then you're using all carbohydrate so for an ultra you're going to be at a lower intensity so you are going to be using proportionately more fat and the reason that's important is because we have unlimited fat stores in our body and fat yields more energy than carbohydrate and we have such limited stores of carbohydrate that we have to supplement with it and in an ultra when you're taking in exogenous sources of carbohydrate with exogenous meaning coming from outside of the body there's a potential for stomach issues and for absorption and introducing all of those those um factors that can often lead to a dnf and so if we think like hey maybe if we teach the body to use more fat because we have so much available then we won't have to rely on carbohydrate as much so how do we maximize fat oxidation so that's kind of the premise behind why this sounds like a really attractive way to fuel for endurance runners i want to i want to take some time and go over the intensity piece of it

a little bit just so everybody kind of understands so stephanie alluded to this concept called the cross the carbohydrate or the crossover point which where you start to utilize a greater proportion of carbohydrates versus fat uh in your in your energy mixture and that occurs at approximately 50 to 60 percent of vo2 max what does that mean right well for for like an elite marathoner elliot kipchoge or these people that ran the london marathon you know last weekend they might be operating between like 80 and maybe a little bit north of 90 percent of their vo2 max like super intensive it so they're they're way past this this crossover point yeah for an average ultra runner we kind of really don't know a good answer because the range is so big right and i've kind of felt this is an i feel statement that if you have a really good athlete that is running a 50k or a 50 mile they can do about a couple of hours worth maybe two and a half hours worth of work so if you think about the climbs like a five hour race the climbs are going to be about you know two and a half maybe upwards to three hours of that five of that five hour race they're going to be able to do that pretty close to a lactate threshold which can be 80 percent of the vo2 max or something like that still way far to the right of this carbohydrate crossover point even in an ultra and as the distance get long gets longer and longer and longer they might get closer and

closer and closer to that crossover point but if you're running and this is the this is always one of like the fundamental things that i keep coming back to if you're running you're running at a decently high percentage of your vo2 max just to run just to like to have that form that have that form of locomotion so it's not like you're operating at like 10 of your vo2 max or 15 of your vo2 max or anything like that yeah absolutely and and there is such a range and it's going to be variable depending on the race and the individual there's going to be times where you're creeping up towards 80 percent maybe when you're going up a hill or even i'm just thinking like the last 20 miles of a 100 mile race like your effort despite your pace being slowed it's going to be pretty high and so it's really hard for us to say yeah ultra runners are around you know 60 to 70 percent because they might be down to 40 percent when they're walking and they might be up to 80 85 percent when they're pushing really hard so that range is is quite large yeah and that and that's i think that that's a valid point to make is a it's not it's not a steady state effort it's certainly not nearly as steady state as a marathon effort or race walking effort which is commonly studied and b there is going to be a bigger range even with the most elite athletes but with you know everyday athletes that are finishing the ludville trail 100 in 24 hours or 20 hours or whatever they're still going to have a tremendous amount of variability there

but i still don't think it's that low like i don't think this is somebody's going to shoot me down on the statement and i'm fine with that but i think only rarely it gets below like 40 percent of vo2 packs i agree with that statement i mean it you know even if you're not moving that fast you're working hard when you've been out there for hours um and it's you know it relative intensity is more important than absolute yep okay so we've got this theory right where you have an unlimited amount of fuel available in your stored fat and the initial like oh i wonder if we can do this type of moment was okay let's try to tap let's actually like try to tap into that via some form or fashion let's try let's try uh some sort of dietary intervention let's use a low fat approach let's use a ketogenic approach what's the fundamental trade-off of trying to do that right so since it takes a lot more oxygen to break down fat there's a limitation because it it's a slower process and so the the exercise economy which is defined as the amount of energy it takes or the amount of oxygen it takes to perform a given intensity is increased so basically what that means is it's harder to do the same amount of work it's more energetic cost for the body and so that decreases the ability to go at a higher intensity um the the energy cost is just

higher when you're relying more on fat yeah so there's an economy penalty to play and that economy penalty if the breaking two project by nike and the 159 uh project by inos has taught us anything is that in these elite marathons in an elite endurance per an elite endurance sport economy is one of if not the hero metric that we you know put at the very very top of this pyramid it is the beacon of light that everybody's trying to aspire to so much so that we've got shoes that are now considered mechanical doping and you know should they allow pacers and then in what type of formation all of those interventions are designed to reduce running economy or to make running economy better right right um that's certainly true at in in those types of sport at the elite marathon but when we translate it to ultra marathon is that actually as important well it's not as important in terms of like because speed becomes not irrelevant but it's just you know there's there's a lot more room for um for error or for i guess just you know speed doesn't matter as much if you lose a couple minutes you're not going to lose the race where in a marathon you lose a couple seconds you might lose the race so in like the the quick and easy answer is no it's not as important but it actually is when you're talking about being out

there for hours and hours if the energy cost is a little bit higher like that's going to that's going to add up over the miles that you're out okay so the way that they've the way that they've tested this that we've alluded to earlier is they view primarily not exclusively maybe not even primarily but one of the big ones that gets a lot of attention let me put it that way is with elite race walkers which i've always found fascinating because and cool from our perspective because i think that they're that's more analogous than ellie kipchoge trying to run under two hours it's more similar to ultra running 100 and so what one of the studies that have got gotten a lot of attention is the moniker of this is a supernova study and they take a group of elite race walkers and they put them into a high carbohydrate group a low carbohydrate group and a periodized carbohydrate group they run them through that intervention and then they test them at the end of the intervention and that that raised a lot of attention to this study because just like the answer to this question is no some of the original findings to that study is is here yes exercise economy is impaired when you go on to a low carbohydrate diet and that is the mechanism for the performance impairment so then you had two pieces right you mentioned earlier that we care about the performance but now we know why right yeah we we care about the performance why no no and now we know why we know why yeah yeah absolutely which is the economy um to go into that study a little bit more because i think it's worth

um just kind of mentioning this was a really really well designed study um with a lot of variables controlled and some of the other studies are much less rigorous where many times the the athletes are just they self-select into groups based on the habitual eating patterns and i'm kind of referring to the the volex study where they didn't control for diet they just had them come in they're like i'm a low carbohydrate i'm a high carbohydrate they gave them the you know the snack that went with the diet did the test and then said hey look at this greater fat oxidation in the low carbohydrate group this study that looked at the race walkers actually had them in a training camp where everything was controlled their meals were customized for them and and we this is something that we kind of glaze over but it's really hard to design a low carbohydrate diet 75 to 80 fat and have it be compliant and so they had registered dietitians and sports nutritionists creating these individualized meal plans that the athletes got every day they got snacks every day they had training prescribed for them and they were in this camp for five and a half weeks so that's a very different scenario and i think it's important to point that out those methods because that just shows the robustness of this

study and as you said they found that in these three groups there was no performance benefit with the low carbohydrate and i don't know if we want to go here yet but there was a little controversy let's go let's let's let's kind of set it up because okay the bridge that i wanted to make was to a study that came out after louise's louise burke's commentary and the title of it is crisis of crisis of confidence averted impairment of exercise economy and performance and elite race walkers by ketogenic low carbohydrate high fat diet is reproducible a little once again alluding to the fact that when you actually do a study the titles are a little bit more wordy and boring as compared to the provocative ones where it's a little bit of commentary but as the title alludes to this is a repeat of a study that they did earlier so the first one's called supernova this one's called supernova two and essentially they were trying to figure out hey could we could we reproduce these results in the in a group of race walkers that we saw beforehand do it do is there a crisis of confidence meaning were the results of the first study somehow invalid and yes go ahead go ahead stuff yeah yeah and so they basically took all the criticisms and comments from the first study and addressed them and basically repeated the study with even stronger methods and in the second study they included females as well in the first

study they only had male race walkers and basically they found the same exact results and one of the this is what i was alluding to just a minute ago one of the controversies was that after that first study there were a few athletes who had improved performance two to three weeks after this study had concluded that were in some of them were in the low carbohydrate group some of them were in the high carbohydrate group but the the point was these athletes actually improved after the study so potentially there is a role for periodized low carbohydrate high fat so in this second follow-up study they they did the same exact methods had these athletes in the training camp in the three different groups and then they had a seven day or sorry 10 day um just kind of back to high carbohydrate or carbohydrate available diet after they finished the intervention leading into a 20k national championship race walk and to see if potentially that was you know a factor that those in the low carbohydrate group after returning to carbohydrate available would have a stronger performance and they found that was not correct so their their conclusion on that was that periodized ketogenic low carbohydrate high fat returning to carbohydrate available does not improve

performance above just having carbohydrate available during training sessions and so once again the crisis of confidence was averted because you can look at something and say okay maybe there were two or three outliers that skewed the results or maybe we just got lucky with the way we put people into the groups or whatever but when you do it twice and you find pretty much the exact same results and one of the things that i think is actually really is really really interesting on the result side with both with both of these is the magnitude of improvement and the magnitude of getting worse between the groups they were almost exactly the same between those two studies and and it really meets the physiology so i've got the second paper pulled up right now and i'll mention it i'll kind of read directly read directly i'll paraphrase the the paper so i get it correctly the high carbohydrate group improved by 4.8 percent they're talking about the time trial that you were just referencing stephanie the high carbohydrate group improved by 4.8 percent the low carb high fat were slower by 2.3 percent and sorry the the periodized carbohydrate group was better by 2.2 percent so you have two groups getting better and one group getting worse and the delta between the high carbohydrate group which is better by 4.8 percent and the low carbohydrate high fat group which was worse by 2.3 percent is about seven percent

and we know that the economy impairment if you just look at the physiology or really this the just the stoichiometric equations that go into that go into fuel utilization and carbohydrate and fat oxidation it's about eight percent difference between carbohydrate between the oxygen that's required to liberate energy from fat and the fact that the delta between those two groups like gets really close to that and you're able to repeat it it's just so stunning right right there's not much argument you can make after that study case closed you know and it not not case closed but this for right now for at this moment in time this is what we know and that's the best way for us to prescribe using sports nutrition to benefit performance okay so where does it get messy when we try to translate this to into ultra marathon because once again this is race walking it's not ultra running we we we very routinely make logical extensions of research done in other sport groups cycling running triathlon cross country skiing is done a lot and and we try and we try to figure out what how to make sense of that and apply it to a different sport and you have to be really careful when you do that because it's not one-to-one translation if i was coaching race walkers

this would be pretty close to one-to-one translation but we're not working with race walkers we're working with ultra marathon runners so where does it get messy right i mean you introduce so many other variables variables when you get into ultra running and it's hard you know even just taking like a research study and applying it to a real life scenario you know there's a lot of room for some gray area i mean not everyone has a registered dietitian creating the meal plans and making sure that they're compliant and they're getting rest and you know so anytime you you take a study and apply the results to an application in real life you have to be aware of that but even more so taking this sport which is race walking and it's it's definitely you know it's the time to complete the event is so much less than even a 50k and you know we work with people who are 50k 80k 100 mile you know they might be out there for days and so this just becomes really blurry and it's like a really you know two different it's like apples to oranges to some extent but it is the closest science we have because there isn't there isn't a really a way to measure this in ultra running like you can't put someone on the treadmill for three days i mean yeah you wait good luck getting an irb to approve that um i always come back to there's also

training implication because we have our athletes train at these intensities all of the time and if we're looking to elicit the most amount of training adaptation out of an interval session or things like that we're asking our athletes to go hard work hard you know do these intervals do these long runs and things like that they're doing these at intensities that are routinely studied and are very close if not exactly the same as a lot of these race walking studies and so if you want to get the most out of that workout you can absolutely or workouts entire series of workouts you can absolutely apply the findings of this research just to day-to-day training to eke out the most results absolutely and you know it's not like when we think of ultra running we think of like people you know skipping through the mountains and so happy and you know running slow and it's like no no no we actually work high end intensity like we work vo2 max because the more fit you are the better ultra runner you're going to be and so yeah you're absolutely correct like these sports nutrition principles that we know for these intensities definitely carry over for ultra running because you don't just go out and run for five hours every day you do interval sessions but the but the i'll play devil's advocate a little bit so we're not we're not having too much confirmation bias between the two of us the the devil's advocate piece of it is ultra running is at such a low intensity that a you can't as apply as much of this research

as you think you can into certainly into the race scenario which i think there's more validity to that than to the other piece um but but b because it's at such a low because it's at such a low intensity that's what that is what lends itself to be more favorable towards people who are better fat oxidizers right right and i mean you know being able to maximize your fat oxidation is something i would say is important for an ultra runner but it's not necessarily done just through manipulating diet a lot of that is through training adaptations as well and i would say that you know day-to-day diet is very important and you know you don't have to go extremist and like i'm eating this diet but having a well balanced diet that we know supports endurance athletes is important for ultra runners as well yeah and i think a lot of times when we start to look at these studies we get too narrowly focused on the very specific like fuel utilization outcomes of these interventions and not broaden it out to okay what does this diet mean mean as a whole to this person and interestingly enough i wasn't planning on bringing this up but i might as well because it's a really salient point because this latter study the crisis of confidence study that we were just talking about was done so well one of the kind of one of the kind of repercussions of that is they can take pieces of it and create new research based off of it and one of

the pieces that came out is it turns out that people that are on the low car low carbohydrate high fat intervention had poor markers of bone health now that's not to say they're all going to get stress fractures tomorrow that's a little bit of a leap of faith but as a precursor to bony injuries that is certainly something that would that would be concerning and so once again i kind of take it out of the fuel utilization standpoint and say okay what does this mean for their overall health injury susceptibility and things like that right right and i think you really have to look at the individual and get to know them to really find the right diet per se i i always think of diet as the foods that an individual chooses to eat not like a a list of foods prescribed by whatever the title is so finding that that correct diet for the individual really depends on a lot of factors that are outside of just performance 100 okay um before we get into our last question i'm gonna let you think about this for a little bit first off both of these papers are open access i'm gonna have links to them in the show notes they are dense and i've heard a full disclosure it'll take you a while to get to get i've got it'll take you a while to get through them i'm looking at 70 pages of printouts on my desk right now they're not for the faint of heart let's put that way fair statement yes yes okay um are there any other big nuggets of wisdom from either of the two studies that we looked at stuff that's worth bringing up

i just think this goes to show like you know how how much because you know we've heard so much about the low carbohydrate high fat diet and just really looking through these reviews of like the studies that have actually done this are quite there's quite small um cohort of studies so most of the information that we are hearing is through social media and i think that's worth bringing up because it we're just bombarded with it and right now that's how we connect to each other so it's almost like you know daily i see stuff daily um and i think as a consumer of this information it's really important to not just take it for point blank and to think about it like okay where where is this coming from and it's sometimes hard to distinguish but if it's just someone who is just writing an article who read the abstract and doesn't know that this is done in mice or this is done in triathletes or this is like you know not looking at the methods you have to be a little bit careful with the interpretation so what you're saying is the body of anecdote is greater than the body of research absolutely and it's kind of you know most of it is is pseudoscience or false information yeah 100 okay we're gonna get to our last question i've kind of built this up too much i think um but to set it up so we've got this like 14 year history of looking at uh louise burke's commentary starting with fat adaptation for athletic

performance the nail in the coffin the answer to that question was yes and then we move on to the next question re-examining high fat diets for sports performance did we call the nail in the coffin too soon the answer to that was no and then we go to the final article crisis of confidence oh no sorry i was reading the wrong one ketogenic low carbohydrate high fat the future of elite endurance sport question mark the answer to that is no so we've got this like 14 year pattern of looking at this body of research and kind of coming to the same conclusion what would it take i'm gonna answer this question too what would it take to change your mind stuff yeah so i've thought about this a lot and i think the first thing would be a really good randomized controlled study that has pretty rigorous methods and strong statistical analyses and then that it's repeated i think that's the key yeah i mean that's first actually seeing a good study produced that shows actual benefits in performance not just metrics measured in a lab but actual performance that's going to be the first thing where i'm like okay tell me more and then wait for something to be repeated whether it's the same exact methods or another study done by different authors that finds the same conclusions of improved performance that's when i'm really going to be open to it and and i'm not someone who's like carbohydrate like that's my thing and nothing else i'm just i'm invested in performance and what is best for athletes so

i'm very open to having it change i just haven't seen anything with results or conclusions with sound methods that has convinced me so not one but two randomized control trials it's it's interesting that you put and we didn't we should go over this that that you think that it's important that it's randomized which go ahead go ahead yeah and that's you know a lot of times these groups are self-selected because i mean it's easier you're not if you're someone who habitually eats more carbohydrate and you're put into a group where it's low carbohydrate high fat that might impact your perceptions of the outcome of the study and therefore performance and so a lot of times and even in louise's study they were self-selected into groups um it was very well controlled while they did that but oftentimes it's like okay so what do you identify with and that that's the group you're in yeah i think that that makes the results all the more powerful is the fact that they selected they self-selected hey i want to be in this group i want to be in that group i want to be in that group yes which means that they they had a sense the participants these race walkers had a sense that that intervention was going to be superior for them and still there was this very market i mean six percent from tip to tail four percent improvement to two percent to two percent getting worse that is at the olympic level it's the difference

between you not even getting to the trials right right it's a big difference and and within those groups there was pretty even distribution there was 10 subjects in the low carbohydrate high fat eight in the periodized carbohydrate and then eight in the high carbohydrate so it wasn't like it was skewed with a bunch in one or the other yeah so stephanie wants two randomized controlled trials good luck that those are hard studies to pull off i actually so i i agree i agree with that i think that those would both be good to see but i would actually like to see a crossover design to see the individual nature of how these interventions would work so just to just to kind of level set every for everybody that's listening the the type of study that stephanie is referring to is where you take a group of 50 people and you say okay you're in the first group you're in the second group you're in the third group you're in the first group you're in the second group you're in third group you're randomly assigning those 50 people to the interventions that you are doing in a crossover design you're having each individual person do each of the interventions and that tends to tease out the individual variations because you can see okay if we have steph do a high carbohydrate diet she performs like this then we put her on a on a high fat diet and she does that we can compare kind of steph to steph across those two interventions and as you know nutrition is highly individual and i think a lot of what we see

in the anecdote that we were referring to earlier reflects that individuality of how people react not the whole thing but some of it at least and a crossover design would be really interesting from that perspective to see are there a group of people that these people always react better to the high fat stuff or these people always react better to the high carbohydrate stuff i just think it'd be an interesting way to look at that would be very interesting and i think the reason this hasn't been done is because that's a really really hard both of these both of our asks are really hard research study to pull off especially when you're talking about elite endurance athletes they're so picky and for good reason right they're invested in their performance so they're not they're not always open to interventions that may or may not help them improve i'm actually very impressed with this study with the these athletes that they were able to recruit and manipulate like this um because that's not something you see all the time and have such a tightly controlled five and a half week study yeah i mean when they're when their vocation or their profession is kind of on the line it's a different it's a different kettle of fish to get people right but let's just throw this out there that we're both interested in the study so if there's anyone who really would like to fund um a study on elite athletes i think coop and i are kind of in the market um we'd be happy to you know partner up with the lab and put out our first uh randomized controlled crossover study there we go you can

have you can have it stuff i don't want to get my hands that dirty in this stuff we'll report back in about five years five years would be at the at the very lower end of that whole spectrum i'm just thinking about it if you wanted to do if you wanted to do a crossover study it would take at least half a year maybe a whole year because you'd have to wash it out yeah and depending on how many subjects you want i mean to get statistical analysis you're probably going to need 15 to 30 subjects and yeah it's so easy for us females working around the menstrual cycle to control for that we've got yeah we're talking years it'd be it's so easy for us to think about and there's no consequences of us having to do the work i know let's just design this for somebody else oh man okay somebody will take take us up on some uh enterprising graduate student or PhD student is listening to this we'll have to take us up on it um steph that was awesome yeah thank you for your time really appreciate it this was uh we'll have to do this again at some other at some other juncture huh yeah it's fun to kind of go through the literature awesome and there you have it there you go much thanks to stephanie for coming on the podcast today i always appreciate it when i get to talk nutrition with stephanie as you all can tell she is very well versed in this particular area and she's a heck of a coach to boot if you think a coach like stephanie or any one of our cts coaches is the right coach for you maybe you've got a big event lined up

the summer that just scares the crap out of you and you want to get the most fit possible hit me up on social media or go to train right.com i guarantee you we have a coach and a coaching package that is right for you and i am more than happy to discuss this with anybody and get them with the right coach we love working with athletes of all different types and abilities and experience levels that's what we do as a living we're coaches here so if you think that if you think coaching is something in your future go ahead hit me up on any social media platform and we will get the ball rolling appreciate the heck out of everybody listening today and as always we will see you out on the trails you