Episode 450: Fat Oxidation Levers | Dr. Matthew Cook

Dr. Matthew Cook is a Senior Lecturer in Sport and Exercise Science at the University of Worcester. Dr. Cook has worked with a range of athletes including cyclists and runners. He joined the podcast to discuss the topic of fat oxidation as it pertains to endurance training and racing.

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Episode Transcript:

HPO Podcast: Matt & Zach 0 All right. Matt, thank you so much for joining the podcast. I'm excited to dive into some some topics with you around fat oxidation and maybe a little bit of just exercise science in general. Yeah. Brilliant. Yeah. Thank you for having me. Yeah. Um, I'm happy to share with your listeners as well. This is my first podcast, but, uh, I'm, uh. Yeah, excited to kind of be here and, uh, I suppose to share some of my expertise, some of my, uh, experiences in the lab and some of my kind of research findings as well. And hopefully they're kind of useful to your listeners. And, uh, the audiences get something out of it. Yeah, absolutely. I'm I'm honored that I'm the first podcast that you've done. I know it's, uh, it's something where I find it interesting because it's like podcasting in general has grown so much. And it, I guess the internet in general, to sort of gives us this opportunity to jump into some areas that otherwise would maybe be a little harder to access. And, um, I'd love to see that more like professors and PhDs and researchers and stuff are sort of coming out of the classroom a little bit, or coming out of the lab a little bit and jumping on shows like mine to kind of let us kind of dive into your brains for a little bit and see kind of what your what you guys are finding out there. Sure, sure. Yeah. It's some. I think it's probably worth mentioning as well. My background I am an academic. I work in university, and a lot of the people that probably listen to these maybe might be coaches. They might be athletes themselves. I might be lucky enough to get a few other academics, but if there's some nice practical messages that come out of our talks that hopefully is beneficial to people that are listening to maybe implement things that they they're going to do in their own training or coaching as well. Yeah, absolutely. I think there's some of all of that, that tune into this podcast. So, uh, we'll, we'll get the word out. Um, maybe, maybe we should kick things off with a little bit about kind of, uh, what you do, where you work and things like that, if you don't mind just giving us like, a brief introduction as to kind of your, your, your day to day responsibilities. Yeah. So I'm an academic, but I work in a university in the UK called the University of Worcester. Uh, I think Worcester is probably famous for, uh, Worcestershire sauce. Everything. Everyone obviously has a, uh, difficulty in pronouncing that, but so in terms of like kind of where that is in the UK, we're north of Birmingham. Um, so we're north of London, but we are south of Birmingham, so kind of in the, the Midlands of the country. Um, I've worked at this university now for eight and a half years, and I teach sport and exercise science, uh, on kind of undergraduate degrees, master's degrees of different, um, different types. But my, my research interests are kind of exercise physiology, sports nutrition. And I've done quite a lot of work on the effects of blackcurrant and its effects on, uh, exercise physiology responses, uh, metabolic responses during exercise. And we've done some cardiovascular, um, work as well. So that's kind of my, my background. But here at Worcester, I suppose, before I joined Worcester, I was a PhD student and I, uh, I did my PhD at the University of Chichester and uh, again, on that PhD, we spent time, uh, looking at the effects of blackcurrant again on physiological responses and stuff. So, yeah, I've probably spent the best part of. 1011 years now on on blackcurrant and its effects on on physiology. Very cool. And that's definitely something I want to dive into with you at some point during our conversation here today, because that's something I've been using since the start of this year. So it's always cool to see kind of the research and the science behind it and, uh, kind of get an idea of like what possibly is going on. Yeah, it's just fun stuff. Fun stuff for sure. Um, but kind of the overall topic that I want to chat with you about, too is just kind of like fat oxidation in general. Um, and maybe a little more specifically how that pertains to like exercise and exercise performance and things like that. So maybe we kick things off with just a little bit about just what if the listener is just kind of thinking, okay, I'm going out for this run or this ride or this endurance activity, my body is using fuel to power that. Um, what is like the fat oxidation part of that? And why is that maybe relevant for someone who's going out for for a run in the morning or a bike ride or swim or something like that? Yeah, sure. So, uh, I'm going to take this quite broadly. Uh, on metabolism, we we consume three energy substrates carbohydrates, fats and proteins. And we can metabolize all of those for the production of energy. And that energy we can then use for exercise. Now measuring protein metabolism can be done, but it's quite difficult. But also it only produces a very small contribution of energy to our overall metabolism. So we kind of always tend to really focus on the other two. So carbohydrate use and fat use during exercise. And we, we call those um carbohydrate and fat oxidation. Um but essentially when we are at rest we metabolize mostly fat with a very small contribution of carbohydrate to our overall energy expenditure. But if you then go out on a run or cycle or any form of exercise, the your oxidation rate of those substrates is typically tied to the intensity of the exercise. So as you increase the intensity, your carbohydrate utilization tends to increase in a very linear fashion. Pretty much all the while, it will go all the way up until when you can hit your max and watch an uptake, which is also known as your VO2 max. But your your fat oxidation, your fat utilization tends to increase in like almost an inverted U or an N shape, so that at very low intensities of exercise or at rest, there's fat utilization, but it's quite a low level. And then as exercise intensity increases, typically to around moderate intensity, which we would say maybe 55, 65% of your max, that's when it tends to to peak. And then there's a bit of variability in that. Some people are able to get, uh, you know, a higher percentage of their VRT max. Some people are a bit lower, depends on diet, training status, etc. I'm sure we can talk about those in a bit, but, um, Once you're going to hit that peak, it then tends to drop quite quickly so that by the time you're you're at VO2 Max, you're, um, very near VO2 max. Your fat oxidation is pretty much zero. And in an exercise physiology lab we can easily measure this. It's very difficult, um, to kind of measure this in the field. Almost impossible unless you've got any kind of respiratory kit. And the reason we do it with, with respiratory equipment, uh, in an exercise lab, is because you're going to need the amount of oxygen people use and the amount of carbon dioxide they produce and the volume of gas that they breathe in and out of their lungs. And then with a series of equations, you can then work out how much carbohydrate and fat people are using during exercise. I suppose the other, um, piece of information that that people need to know as well is that while we consume those foods, um, in our in our diets, we also store energy. And I'm going to focus on, on fat carbohydrate here. Carbohydrates are stored in muscle and in our liver as glycogen. Essentially, this is, if you were to look at it under a microscope. It's lots of molecules of carbohydrate attached together. And what that does is it provides a store of carbohydrate. And when we, uh, undertake prolonged exercise that store, uh, as glycogen can get broken down to help fuel the activity. Now that that store is typically limited, most people probably around 90 minutes to 2 hours of, you know, moderate to heart exercise. And you're probably starting to deplete your, your glycogen stores. Now, on the other flip side of that is your fat stores. Even for very lean athletes. You typically talk in almost unlimited stores of, uh, fat. And those are the you know, that's the kind of interplay, that's the, um, the balance, I suppose that people strike when you're doing endurance activity in that you don't typically want to run out of muscle glycogen because it's useful for very high, intense efforts thinking like sprint finishes or trying to sustain high speeds or high power outputs versus at lower speeds, where you're maybe using more fats and not going fast enough to maybe win a race. So there's that difficult balancing act that, um, elite athletes and people have all the time. Does that make sense? Are you happy? Yeah, I know that's an excellent foundation to kind of base the conversation off. I'll just ask or maybe confirm in the in the case of just the fat oxidation side of things. You mentioned kind of that U-shaped curve of fat oxidation for listeners, if I understand you correctly, that's absolute fat utilization versus a percentage of your energy needs is where that U-shaped curve is being shaped versus like at rest. The fat oxidation percentage is likely quite high and then is going to possibly go down in a more linear fashion over the course of that aerobic intensity spectrum, whereas your total fat utilization is going to increase and increase increase. Once you hit that 65% VO2 max, give or take, depending on the individual lifestyle factors will start to come down as your body demands more, um, more carbohydrate for the for the intensity being produced. Yeah. Uh, I probably should clarify that. Yeah. So I, I'm saying when you measure it and you record it as an absolute amount, so grams per minute. Um, there are different ways in which you can report it, but milligrams per kilo of fat free mass, etc.. But in our lab we tend to just go with the equations for for grams per gram per minute essentially, rather than, as you point out, that percentage to overall energy expenditure. You can work them out that way as well. But um, it that that's typically when you're doing a fat max intensity protocol, you would like to know your maximal fat oxidation rate. And that rate is provided in absolute terms. So grams per minute. Um, and we say grams per minute. It's typically not many grams. You know, it's it's normally for most individuals should we take a broad sweeping stroke of people who are athletically fit. You're probably looking at 0.5 0.6g per minute. So it's not a massive amount. Uh, per minute. But then when you think about over many minutes of exercise that then that starts to add up. So. Yeah. It's absolute terms. Yeah. Yeah. No that's good. That's a good uh follow up and then. Yeah. And you're, we're talking about essentially 9kg/g. They're from fat. So uh, those minutes pile up to become a portion of whatever your energy expenditure is going to be. And like you said, that can add up. Uh, and it's worth looking at, too, because I think with, uh, well, especially nowadays when we have like a lot more people entering endurance athletes, and then one of the big questions they often ask is, well, how should I fuel these things? Like, what do I need to do? And you know, that ranges greatly from people who are doing next to nothing, to people who are, you know, trying to eat as much as possible and maybe not paying attention to whether it's fats or carbohydrates or not. And, and, and then everything in between. So, um, I always tell people that, like, you can start kind of getting yourself into some ballpark figures by kind of addressing it the way that we've kind of talked about it so far, which is, you know, like the intensity is going to determine heavily that demand. There's going to be a piece of that equation of just what is the duration you're out there for? Because if you're out there for a very short period of time, that's very intense, you're also not likely to dip into that liver or muscle glycogen in a way that could be exhaustive versus like something like a half marathon or a marathon where you very much may you're going to be lower on that intensity spectrum. So your gram per minute utilization of carbohydrates might be lower, but that compounds over a much longer period of time. You can find yourself in trouble. And and and then it gets a little more interesting. So you know in the past what I've done for races choose I'll just go in and get a metabolic test done and just see kind of where my fat oxidation rate is across that, that spectrum of intensity up to VO2 max, and then kind of figure out like, well, based on the race intensity, I'm doing what is, uh, you know, where does that fall from? Like a pace and intensity standpoint. And then I can sort of get an idea of just the ratios of carbs to fat that my body's my body's demanding at the intensity I'll be asking it to perform at. And that gives me a little bit of an idea of like, okay, how much or how much carbohydrate should I be taking in in order to defend that exhausted side of the equation? Yeah. That that that sounds like a a typical approach. Uh, a lot of the people that we get into our exercise physiology lab that are paying for like a lactate threshold or VO2 max tests, typically that combined. Um, when I kind of write those reports up for individuals, I do give a slight insight into their, uh, carbohydrate and fat usage during exercise. It's not a traditional fat max test where the the conditions where you measure your maximal oxidation rate and the intensity of your act or the the intensity of exercise where that occurs that that's typically done under quite uh, strict uh, pre uh visit or pre experimental conditions. Typically you want people kind of 12 hours fasted. So doing it first thing in the morning typically no caffeine which tends to be a problem for a lot of people. Most people are uh are often a little bit upset that you ask them to come into the lab with out a, uh, morning coffee, etc.. Etcetera. Um, you know, no exercise the day before, well rested, etc., etc.. So if you're doing those types of tests to get an idea of your your fixation rate and your fueling strategies, that that's really good if you're an endurance athlete, because it does help feed into that, um, fueling uh, strategy. And, and kind of, as you say, the intensities that you can kind of hold for various energy substrate usage. Um, yeah. Yeah. It's interesting. And, you know, I've been fortunate to have access to some of that stuff. I think it's, uh, it's getting more and more accessible. As you know, universities open up their departments for people to come in and, you know, pay to get that test done. Or now here in the States, we've got a lot more just kind of like private services that offer that sort of a thing to so people can go in and get those tests done and kind of have that blueprint available to them and, and maybe start building out a strategy just a little more specific to them at the individual level. But if someone's not in that position, is there like some population level markers that we can maybe use as a starting point where the one I oftentimes think of as like, I believe like. Based on what we know, if someone is like at their aerobic threshold, someone on like say a moderate carbohydrate diet or around, there is probably going to be about a 5050 split between fats and carbohydrates. As far as I'm aware that it is quite variable. However, if you are, you know, let's say you you were to use a three zone model below, between and above lactate threshold. You would assume that if you are below lactate threshold, the vast majority of your energy is coming from probably fats. It's that between point where you probably start to see that shift, and then above, uh, your lactate threshold, uh, or above lactate threshold two, you would typically start to probably transition into a high carbohydrate usage. Now again, I, I'm using scientific terms there. But if you've got access to a lactate analyzer and they are maybe a bit more portable, you can buy, um, relatively cheap units, take them to a, um, you know, basic gym or take them trackside, etc. and then measure your pace at different speeds. That might then give you an indication it won't give you the absolute terms in grams a minute. But it certainly gives you an idea of, you know, paces and then probably a flavor of, of where those different energy substrates might be. Mhm. Yeah. No that's that's great. And I kind of like looking at like a three zone chart there just for most simplicity's sake for people who are like trying to wrap their heads around this for the first time. And it's the other way I sometimes will look at that is if we take those, those thresholds, um, and we look at those as the crossover points between me are easy into moderate and martyr into hard along the aerobic intensity spectrum. I think people can kind of appreciate the sensation they get when the run starts going from just like, I feel like I could do this forever to, okay, this is still sustainable, but I'm focusing a lot more or this is sustainable, but I focus a lot more. It's like, okay, now I have to focus pretty hard to maintain this. If I go any faster, things maybe start getting shaky. And, you know, people tend to, you know, the body is good at sending signals when you start getting into those areas. And, uh, as a coach, I always like to kind of teach people about, like using all the other tools that maybe feel a little more objective, like heart rate or feel tests that determine kind of things like paces for certain durations and things like that, or if they have it, metabolic heart testing and things like that, to kind of give them a something to pin those sensations onto and then allow, allow them to kind of learn their perceived effort a little bit more of a fine, finely tuned way. Um, but then it kind of gets into the stuff that we're talking about, too. It's like, what does that mean from a fueling standpoint? So it sounds like what you're saying is, like, when we're in that easy category, we can be pretty, we can assume pretty safely that the majority of the metabolism is coming from fat. If we skip over that middle section and go into that, that third zone, we can be pretty certain it's going to be a majority carbohydrate. It's that spot in the middle where there's a lot of individual variability. If you want to make a broad brushstroke statement, I would suggest for, for. For the vast majority of people that will be fine. Yeah. At least from a point of I know nothing to. Now I know something. Yeah. That's fine, that's fine. You can always dig deeper, though. Yeah, yeah. I mean, in terms of variability, you know, if you were to come exercise for the first time or so, sorry, if you were to come at training for the first time where you want to, uh, improve in a sport or get ready for a specific event, then then that approach might work. But as you become more highly trained, a a training response that you see is that people tend to get better at oxidizing fat so that their their fat oxidation rate and potentially the intensity at where their maximal fat oxidation rate occurs can both increase. Uh, diet is another one that can bring about certain changes very quickly. But, um, for, for for people who are kind of on a fitness journey or, or undertaking structured training, those numbers can change, uh, over time. So even if you take a measurement. That's great. But we often find that doing repeated measures, let's say, every 2 or 3 months, can help you monitor your training as well, rather than just taking a single snapshot in time and and from a kind of coaching viewpoint that then becomes very important, um, to to ensure that the training is, is working. Mhm. Now that's an excellent point. And it also kind of lends us towards kind of like the kind of the meat of the topic at hand that I want to chat with you about, which is just kind of fat oxidation rates and how we manipulate those or how they change given kind of lifestyle factors and things like that. So like, I think that's a great spot to start with. Like, yeah, let's say someone was deciding to start going on a journey to train for a marathon, an ultramarathon, a triathlon or something like that. And they went in and got that test done at the early stage, and they got that baseline data. That is all going to be at least as it pertains to like the fat oxidation rate side of things, going to be a moving target that they now have, like their initial starting point. And they can use that as like an assessment of like, okay, here's where I started. I'm going to put these different practices, whether it be the training or the nutrition into place. Then maybe I go back and like you said, test three months down the road and see, okay, what did that do. What did that training input? The lifestyle nutrition stuff that I did do to influence that. One way or the other. And I think that kind of leads us into kind of the topic of like, what are the different things that do change that? And maybe if we can put a little bit of weight onto the ones that are going to move the needle more versus less, and then maybe broadly speaking, what are the opportunity costs for that? Because I like to look at a lot of these things as opportunities, especially when it comes to the nutrition side of this. It's like, yeah, I see that as like the really big lever in terms of like, I really want to jack my fat oxidation rates up. I can just drop the carbohydrate down and replace it with fat, and my body is going to jack the fat oxidation rates way up. But then what's the opportunity cost there? Is that going to give me a scenario where, sure, I'm a fat burning machine, but now when I go out and do short intervals, I'm going to be operating at X percentage lower capacity than I would otherwise. So is my trade off of improved fat oxidation beneficial to the degree that it can make up for that performance reduction? I may experience later on in the intensity versus, um, just being a little more gradual with that approach and trying to sort of get a little bit of best of both worlds, perhaps improve the fat oxidation rates, but also maintain the high end performance side of things, too. So, um, maybe we jump into those things, if you don't mind. Yeah. I'm happy to do so that there's quite a few questions and directions. I suppose that can go. Yeah, I put a lot out on the table there. Yeah. Um, I'm happy to start with, you know, this idea of, as you say, increasing foundation. Does that have an effect on performance? And you can dig into the literature and you can have a look at, you know, some studies will show an effect. Some studies don't. I suppose that is the the nature of sport and exercise science research, again, not just in variability of individuals. There's variability in results. And and we're not always blessed with having availability in elite athletes. There's a few papers that I know of where they've changed diets in uh different um so they've changed diets out of elite athletes and had a look at the outcomes for things like race performance, specifically race walking and, um, and their vaccination rate. And it's not surprising if you give a high fat diet for a period of a few days, you tend to see a very quick change in fat observation rate, so that that tends to go up. But that can be at the expense, especially in elite athletes where their, um, their performance is then potentially affected. They've often then got a higher oxygen cost to the activity. Their heart rates can be a little bit higher during the activity as well. And what we call their rating of perceived exertion, their RPE can also be high. And we're talking about elite athletes here. And there's one paper I specifically think of. I roll it out every year to my undergraduate sports nutrition students. And it was a paper that essentially tried different diets. In elite racewalkers, and they showed that the high fat diet, as I said, had all those, uh, responses. Um, but the the athletes performance was, was decreased as a, as I said. But on the high carbohydrate diet, they, they kind of improved over a training program to, to the amount that they would kind of typically expect. The one thing I always take from that paper is I, um, I get the students to read actually how fast people are racewalking. Yeah, yeah. And you look at it and think that that's not possible. Now, you know, I'm going to use kilometers. Now I'm not sure what it is in miles an hour, but, you know, racewalkers I think they're walking at around about 16km an hour, which is about, I think, in the United States that we're about ten miles an hour. You know, try walking at that speed. It's impressive. Yeah. So, you know, part of that is biomechanics and technique and, uh, and lots and lots of training. But you know that even though they are still walking, they are walking at an incredible speed. And, you know, they're still where they're, they're they're obviously high performance athletes. So training and diet have a big influence, I suppose on the overall topic or the overall, um, question that we initially asked, you know, what has the biggest bang for your buck? Well, your dietary intake will have the quickest changes. So if you eat a high fat diet for a few days, that tends to increase fat oxidation quite quickly. Or even if you undertake training in a fasted state. And this was um, some. Again, nice research in sport and exercise science where people undertake training in a fasted state, so you train low. And what that does is it helps bring about training adaptations for endurance performance by increasing mitochondrial biogenesis. So this is the the generation of new mitochondria inside of muscles. Now to help people understand what a mitochondria is, that's essentially a little organelle or a little organ, if you like, inside of a muscle where we metabolize glucose or carbohydrates and fats. And by doing endurance training, you increase your number of those. But they were able to show that by changing your diet or changing your food intake in and around training sessions, you can increase or help to upregulate those processes. Now, it's important that they didn't do them all the time. They were part of a, I suppose, a training program, but you would typically see if you were to go out on a training session in a fasted state, your fat oxidation would typically be higher because you likely got less availability or lower carbohydrate stores available anyway. So that's what you can. That's kind of what people, um, or elite athletes endurance athletes will undertake. And they're kind of called this carbohydrate periodization, whereby then when they undertake a performance event, let's say a tour de France stage or a marathon, they will compete in a state of high carbohydrate availability so that they are getting all the adaptations from, uh, that train low, uh, situation. But then when they're competing is with high carbohydrate. Another thing that is classically known to very acutely affect fat oxidation. Uh, is caffeine. Uh, and that's, you know, that that also kind of relates to why I said earlier today when we get people in the lab, if you're doing a fat Max test, we ask you not to consume caffeine, please. But caffeine is known to increase lipolysis. And lipolysis is the breakdown of fat of stored fats. So that then leads to an increase in fat oxidation rate. So essentially, if you were to go out in a fasted training state with caffeine, the caffeine might put you up a little bit. You might get a slight benefit then from the consumption of that caffeine, but you would be in a fasted state with a slightly higher fat station rate. Uh, I get that's probably quite a long answer to your question, but is it kind of go along the lines of what you wanted? Yeah, no, I think it does. I think like the way I Oftentimes try to summarize. Some of this is if we look for the big levers of improving fat oxidation, rate, their trade off to pulling that big lever heavily is oftentimes going to come at some sort of expense to performance at at least at at least in some scenarios, at least we're looking at like Olympic distance for sure. Or like the study you referenced with the racewalkers, I would 100% agree. Like the biggest like PR issue with that study was the fact that it said racewalkers on it. But I actually had Evan Dunphy on the podcast, who was one of the participants in that study, and just unpacked his training protocol and the paces and the intensities that they're hitting. And it's insane. Like he does workouts, walking where he gets his heart rate up into the one 80s. So it's like, you know, I'm doing like straight up VO2 max, short intervals running to get my heart rate up that high. So it's like from an intensity standpoint like he's these these individuals are definitely like. You know, they're not just like, you know, walking around the block, I guess is maybe what the perception would be when, um, when someone sees the title of that. But, uh, it the way I think about it is like if we, if we want to pull some of those bigger levers, we just have a greater risk of there being an opportunity cost somewhere versus some of these smaller levers that maybe don't look like they're going to be like these big needle movers on fat oxidation rates. They tend to have less trade offs when it comes to things like how our body is going to access and utilize carbohydrates. Um, so then maybe do we look at it as like how many of these littler or smaller levers can we kind of pull and sort of create an environment of good enough fat oxidation rates, but not at the expense of our bodies utilization of carbohydrate? And maybe that would include like manipulation of when you're eating your carbohydrates, like what you mentioned in terms of going out for like a fasted run versus a fed run and things like that, and and being strategic with it where it's like, hey, I'm doing an easy run that's going to be below the aerobic threshold. Uh, maybe I don't need carbohydrate supplementation in order to execute the quality that I'm looking for out of that session, versus I'm heading to the track and doing, you know, intervals. Therefore, maybe that's when I avoid doing my fasted training sessions for because that has a higher quality consequence if I don't execute properly. And it's just a more difficult session to execute. So, um, is is that kind of the direction that you're thinking that this is going to some degree? Uh, I would say so. I mean, we we're discussing all these points with very much a, uh, a viewpoint from an endurance athlete. Now, if you're an athlete that undertakes a team sport soccer, football, um, hockey, rugby, etc., you're going to need endurance components from, from aerobic pathways and anaerobic pathways. And you're going to need some strength components. So to try and bring about, you know, um, changes in those individuals. What you're trying to do is, is concurrent training. You're developing, uh, adaptations to their sport that relate to both strength and aerobic developments as well. And sport and exercise science and sports nutrition always tends to gravitate. I feel back towards endurance sports because they are so much more easy to categorize in terms of performance change. Do a time trial. Please complete this distance in the least possible time. There is a team sport you might have had, uh, you know, the best game of your life, but you might not have one as a team. So, you know, sports nutrition always, as I said, tends to. And sports science tends to gravitate back to these endurance type sports, which is kind of what this glycogen sparing fat oxidation tends to relate very well to because it's much easier to to relate to. Mhm. Yeah. And that makes sense. There's definitely going to be some variance from, from sports to sports and things like that. And, and to my knowledge like when we look at the research the there's maybe some evidence that like even ketogenic diets would be potentially beneficial in certain sports like gymnastics where they're doing very explosive things, but they're for very brief periods of time. Um, and then there's also like a power weight ratio component there that was is maybe influenced by that. But um, but yeah, I mean that just is for, for any for no other reason other than to share like, yeah, we're I'm, I'm obviously biased towards endurance sport and and the research seems like it is as well. But there is a lot more to be considered if someone is listening to this and they're thinking, hey, um, is this just a plug and play for what I'm doing out on the soccer field or, um, in a rugby scenario or something like that? It's difficult if you aren't doing, you know, team sports. As I said, there's that concurrent type training approach whereby you want you'll be doing strength conditioning work. You want strength adaptations, you want strength, power and speed, but you also need some aerobic developments as well. Now, if you were to go out and do, let's say you were a team sport athlete and you go out and do these fasted training sessions and stuff that they're not typically associated with those types of sports and those types of training sessions. It is more your endurance athletes that we look at and where those studies, as I've said, tend to relate to, um, and, and what you the challenges you've always got as a team sport athlete is that essentially you're trying to develop two different things strength, power and speed. Alongside aerobic developments are different pathways. They're different, um, adaptations. So you've got to do two different types of training essentially to, to develop, you know, beneficial fitness gains for those sports. Whereas endurance athletes, it's very easy to measure changes in, in that sport. And typically the vast majority of the training there will be some conditioning, but the vast majority is is undertaking the sport that you are competing in. Whether that be cycling, running or rowing. Mhm. Awesome. Yeah. The, the other kind of thing I wanted to just ask you about a little bit too is like when it comes to if we kind of just go back to endurance sport, I think even within this we have like quite a bit of variability, especially as like ultramarathons are getting more popular and then like the multi-day stuff is starting to grow to where now we have like quite a bit more attention on these races that sometimes take 2 or 3 days, or I just had this guy on the podcast recently, Phil Gore, who set the world record for this Last Man Standing type competition where he made it up to like within an hour of the fifth day. So it's like, you know, when we when we even in endurance sport, we've got this sort of like lumping of um, of, uh, wide ranges of like, you know, the you could go to Olympic distance stuff all the way up to these multi-day ultras. And, you know, for that I find interesting because I think to some degree, we're still in that same spot where you said where it's like. The the training inputs are aren't drastically different. Maybe if you get up to like some of these really long, like through hiking type projects and stuff like that, it could be different. But generally speaking, even with multi-day ultramarathon runners, I think there's a big benefit of them spending a good portion of training, just developing themselves as kind of as a runner, and then all the same kind of priorities and inputs are going to be there and then maybe spend like a block of time getting more specific to their event as a whole, which is going to be where the wide variety is between, say, like the pace someone's doing for A5K, ten K marathon or a 24 hour multi-day ultramarathon or something like that. Um, but where I think it gets a little bit interesting then is like on like competition day fueling strategies, because that's where you're going to have some of that variance, where now all of a sudden we've got a scenario where the person's intensity is so low, they may find themselves in that category of intensity, where fat oxidation is is quite a bit higher, or the majority of the metabolism versus someone running a shorter endurance race where they're in that other end of the spectrum from the aerobic intensity side of things. So they're that's where the conversation sometimes goes when it comes to fueling. So it's like you have this like questionable. How many grams per hour should I be taking in during during a race of carbohydrate. And that's where I think it gets a little bit more interesting from, uh, from an intensity standpoint, from a race, from the race duration that they plan on going and then the workload that they're going to be doing on a per hourly basis. Because, uh, once you get into the longer stuff, you have to deal with potential digestive issues as being a limiter as well. Yeah, absolutely. Um, I, we kind of talked about earlier in the, the podcast, the intensity is very closely related to the oxidation rate of your carbohydrate. And uh, as I mentioned as well, you've got a very finite store of your carbohydrate stores. If you were to go out at a particularly high intensity, 7,080% of your VO2 max, most individuals could probably run out of stored carbohydrate within two hours. And that that would be glycogen depletion. So essentially you then got no fuel stores to help with any kind of high intensity effort, parts of any race. So that's where, as you say, fueling strategies become crucial. Now, if you look at multi-stage events, which are typically very high intensity, let's take is on at the moment the tour de France. Those guys are can some of them are consuming well over 100g of carbohydrate an hour. But that's not surprising when you actually look at the power outputs that some of these guys are producing. And they're up at three, 400W for an hour of cycling power. Now that is a huge energy expenditure. And to sustain that high intensity of activity, they need a lot of carbohydrate. And it is an ultra endurance event, but it's in a much higher intensity than, let's say, some of the running events that you mentioned, where you've got multiple days or you've got to do maybe a hundred miles. You've got that, uh, um, if you're running at a slightly lower intensity, then hopefully you're, you're keeping back, you're sparing some of those glycogen stores. But fueling strategies will become important. Now, if you are starting to consume carbohydrate 2 or 3 hours into the event, I would suggest that's probably too late. All the advice I tend to give people when I work in, um, sports nutrition is you should start kind of throw out. If you start your, you're feeding three, four hours into a 6 or 7 hour event, that's probably a bit late and you won't be able to turn the tide on that. But, um, what you're, you're looking to do is obviously delay fatigue. Essentially you're by the consumption of of carbohydrate or fueling throughout. Now, the amount of fuel you'll need that is dependent on the individual, the sport, the intensity, and also, as you say, what you can tolerate. Now, if you're going to try and stick 100g of carbohydrate in per hour, most individuals will really struggle with that. And they need to actually undertake a process of training the digestive system so you don't end up with gut issues. So you get um, uh, yeah, you get distress essentially by consuming that much carbohydrate. So people, you know, elite athletes will undertake training, as it were, as it were, to make sure that they can process those huge amounts of carbohydrate. Now, for us who are not elite athletes, I would always suggest that you make sure you've tried your nutritional strategy in training before you ever go and do it in a race, because you don't want gastrointestinal distress, you know, a third or halfway into your event. And and that fueling strategy. Now stick with it. If you've got that, the data, if you've got the guidance, if you know that you're going to be getting through one gram of carbohydrate per minute, well, that's obviously 60g in an hour. Well then that might give you a really good idea of how much you should be consuming across the hour. And one gram a minute of carbohydrate is not is not a. That's probably a sensible amount of that. People would probably, um, metabolize. If you go back to that fat max curve, we talked about fat oxidation rate. As I say, carbohydrate oxidation rate is linked to intensity. And depending on the intensity you're running or cycling or or any activity, you can have people oxidizing two and a half, three, four grams of carbohydrate a minute. And and you suddenly start to see, well, the this 90 minute store of glycogen. Yeah. You can eat into that and 90 minutes is. You know they're very achievable. To to to deplete that. Yeah. So yeah that was a lot of great stuff there. And I think it just yeah it references like being very aware of the task at hand and then like your workload rate where we look at the tour de France, which is one of my favorite examples here, because it's like you said, it's got that blend of ultramarathon in it because it's, it's was it 30 days? It's like, you know, they're out there doing and they got like a couple days in there that they're not doing a race. But it's like the energy, the energy output for those guys are like somewhere in the neighborhood of like 6000 calories a day during the competition. And there's because it's like spaced up in, like what ends up just being like a gigantic interval session over multiple weeks. You have that scenario where you can maintain way higher power outputs, but for longer durations of time, just like you'd be able to do if you did a short interval session, you could tolerate the intensity that for a higher amount of volume than if you just tried to do all that work in a straight shot. So that changes the metabolism and it also changes. The other thing I find interesting about is some of those stages are long enough to where it's like, I wonder with like some of those really high fueling strategies where these guys are hitting up to like 150g per hour, how much benefit they're getting from they're getting off that bike at the end of that stage with compared to what maybe we would have seen from fueling in that cohort historically, they have a whole meal in their stomach already getting processed and ready for that next day. And when you have that really tight window from one day to the next, and then compounding that day after day, that it's going to add up to be like a consequential, uh, piece of the puzzle, too. So a lot of moving parts with like the tour de France and things like that. But yeah. And then when we bring it back down to what you were saying, where it's like now we have maybe a single day ultramarathon that's done at a low intensity, but still, you know, 24 hours in duration potentially. Um, I think like looking at workload is important because you take the person, say we take a 100 mile ultramarathon race, the person who wins that race is going to finish roughly twice as fast as the last person who crosses the finish line within the cutoff. And when you look at that, it's like they both covered 100 miles. They probably both had a similar amount of energy expenditure over the course of that 100 miles, but one person had half the time to account for that energy expenditure, whereas the other person had two x at the time. So when you get the front of the pack going 100, 110, maybe 120 plus grams of carbohydrate per hour, what does that mean for someone who's middle to the back of the pack? And like you said, maybe that's going to be getting you a little bit closer to that, like one gram per minute versus two three grams per minute. I think it's also important to recognize as well that when those athletes are consuming 100, 100 plus grams of carbohydrate per hour, I'm I'm guessing you've probably covered this in your podcast before, but they will not just be consuming carbohydrate from what we call one source. It'll be carbohydrates where you you utilize multiple transporters within the digestive system. So typically things like glucose and then fructose, they tend to be absorbed in a 2 to 1 ratio. So you can get up to, you know, 90 maybe 100g of carbohydrate consumption per hour. By combining both of those in that kind of 2 to 1 ratio, glucose to fructose, and that that's what you will typically find that those athletes are doing versus if you need a lot less per hour, if you're maybe 30, 40, 60g an hour. There is questions as to whether you would need multiple transporter carbohydrates in that event where you might just get away with something like glucose. And one of my favorite. I'm going to slightly digress, but one of my favorite activities to do is get my undergraduate students to make their own sports drinks. And we ended up, you know, we've we've got, you know, bags of dextrose, we've got fructose, maltodextrin, whatever. And we, we get them to actually weigh it out and then, you know, mix it with water and they can try try it. Now typically we do it on flavored. So it's very very sweet water. Or you can sometimes put a bit of fruit squash in there. But they get the sense then of actually what, what it's like to try and consume that amount of carbohydrate. Oh, and then you have to exercise it. Well, that then that's a challenge. So, um, yeah, it's it's a nice experience that the students, I think tend to remember. Um, and also it gives you an idea as well. And actually when you measure out, let's say 60g of carbohydrate and you put it on a set of scales, it's actually quite a surprising amount. And then when you think, well, some people are consuming double that. It's very surprising. Yeah. Yeah. It gets it gets into the the logistics and then the digestion of the whole process when you start looking at it into those, those higher numbers for sure. Um, one thing I wanted to kind of follow up on too, because you mentioned I think is really an interesting topic. Uh, maybe a little more important for the longer duration ultramarathon style events. But when it comes to like the fueling strategy, you mentioned that like waiting too long, like 3 or 4 hours and is probably too late, you've maybe gotten yourself into a little bit of a hole that's going to be difficult, if not impossible, to dig out of. Is there any evidence that that you should delay carbohydrate consumption, say, like for breakfast before an event like that, and maybe in the early stages of the race to potentially start off with higher fat oxidation rates and possibly maintain them and then start that fueling process maybe 30, 40 minutes into the race versus kind of at the start line or having like a really carbohydrate dense breakfast, assuming we're doing a morning start here. Yeah. Uh uh, the short answer is, I don't know. However, it is important to potentially recognize that while I say you've got fat and carbohydrate metabolism when you're at rest, 85, 90, 95% of your energy is coming from fat. But as soon as you start exercising, as I said, there's an increase almost linearly in carbohydrate use during during exercise. So I would suggest that, you know, even if you're, um, delaying it by, you know, 30 minutes, you're already using carbohydrate source, uh, as soon as you started exercising. Even if you've got a higher oxidation rate, there's still some use of carbohydrate. So you know that that fueling strategy, you know, if it got delayed slightly, then that's fine, I suppose. Maybe there is a caveat to that. If people wake up in the morning, they're nervous, anxious, etc., and you don't want a particularly heavy breakfast then then maybe, you know, if you try to avoid, you know, avoiding something that's got lots of fiber in it, that's difficult to digest before you start the event. That would be probably the advice I would give that easy to digest high carbohydrate foods. Things like fruit juice. Might be something to consider to just get some carbs on board before you start that ultra event. But you know, I accept that everybody's got different kind of race day routines, strategies and things that work for them. So yeah, it's ultimately probably down to the individual as well. Sure. Yeah. And yeah, and I'm sure also just that probably just like all this stuff plays into the, the demands of the individual within that event to where probably a higher risk for someone pushing the front of the pack that are going to be getting up to that 90 plus gram intake need to be starting with any sort of potential, uh, reduction in that versus a person who can kind of stay maybe a little bit on that lower side or closer to that gram per minute side of things. Uh, with that too. Um, yeah. The, the maybe it's a good time to kind of jump into some of the other stuff around fat oxidation rates and how those maybe are impacted from both, like dietary or supplementary type processes. We talked about caffeine a little bit there earlier in terms of that being something that will increase fat oxidation rates, is is that something where if a person is like, all right, I'm going to leverage caffeine in my event for the reduction in perceived effort, can they kind of follow the protocols that are in place for that and just assume all right, I'm also going to kind of get a free extra there with improved fat oxidation rates. Or is there like a separate protocol that maybe maximizes that that needs to be considered? I think there's quite a lot to work through there again. Um, I think it goes back to the point I made earlier. If you're going to do something on race day, practice it. Make sure you try it in training first. Don't don't try it for the very first time on race day. Um, yeah. Caffeine is a classic aid in sports nutrition. It's one of your big three carbohydrate caffeine and creatine and caffeine known to increase endurance and, um, sprint power events. Um, but also has effects, you know, psychologically and metabolically as well. So as I said, it does increase fat oxidation use. Um, if you are naive to consumption of caffeine. So when I say naive, you're, you're somebody that really doesn't typically consume it at all. I wouldn't, as I said, do this for the very first time on race day. And and also be careful, you might not be the type of person that would benefit from the consumption of caffeine, because you use some of the gels or caffeine supplements that you can buy. Do contain quite a lot of caffeine. Um, but if you're an individual that consumes it, you know, a low amount per day or, um, you know, you you would probably see a benefit. Although, you know, I know it's not the topic of this podcast that there is, you know, data out there to suggest those that respond really well somewhat. And then a low, uh, no responders at all to caffeine and that that's an entirely different topic or conversation. You know responders and non responders to supplements. Um, I think part of your question as well is also, you know, what other supplements or processes can people do to increase validation. And I'm happy at this point to talk about some of the work that I did on my PhD. Yeah. Uh, and I still research on today. And that's why we've given people doses of blackcurrant. Over a period of seven days. And then we measure in the exercise physiology lab their fat oxidation during a variety of different activities. So we've done, uh, treadmill walking. We've done cycling at different intensities. And we're able to show that the consumption of a concentrated blackcurrant extract is able to increase people's fat oxidation rate. Now again, that that the finding is quite variable, a bit like caffeine or any nutritional supplement. Some people respond a lot. Some people not so much. But I can think of about 16, potentially 17 studies now that, uh, have investigated the effect of blackcurrant on fat and carbohydrate use during exercise. And there's about. Uh, eight nine of those studies that show, uh, an increase in fat oxidation rate from, from the consumption of blackcurrant. Now, some of the kind of consistent findings that we've shown are that, um, and I know that the, um, the companies support your podcasts Korans so that they're a black currant company that, um, provide and, um, New Zealand blackcurrant in the form of capsules. And we've shown that if you take that, as I've said, for, for seven days before exercise, that tends to increase your fat oxidation rate. And we've done a little bit of work on dose response as well, seeing because, uh, athletes love to do this. Oh, more must be better. So therefore they take lots more than they potentially need. Um, we've done a little bit of dose response work, and we've tended to show that the consumption of two capsules of blackcurrant, which contains around about 200mg of anthocyanins. And I'll come on to what those are in a minute if, um, if we've got time. But that that tends to be the kind of active ingredient that we, we think is having this effect, um, on increasing station via blackcurrant. Yeah, that's interesting because I think it's like anytime we get into the world of supplementation, we have to probably share with people. It's like the research on a lot of supplements is what it is. But then you also have the marketing side of it too, where it's like, okay, well, this product showed in this study to do this, therefore I'm going to put that in my product. And then you have to get to the dosing of it. And whether they actually used a substantial enough amount to actually do what the research showed, I think we see this with like exogenous ketones and things like that to where, you know, the dose is very much going to be going to be important when it comes to the results that we see in any of the research, positive or negative. Uh, but yeah, with um, with a, with a blackcurrant, it's uh, a question I had about that is like we have like this potential increase in fat oxidation rate from taking that. Is there, is there like a, a time frame in which, like that those two capsules are going to be beneficial before you would have to sort of re-up in order to kind of maintain those benefits. I'm thinking like outside of the realm of I'm going to do a workout this morning. In that scenario, I probably take two and then be done with it versus now I'm out on a race that I'm going to be out there all day. Do I take more after, say like four hours, five hours or something like that? Again, a really nice, interesting question, and I suppose there's no answer to it. Well, the the answer in sports nutrition all seems to be in science is it always depends. Um, now you know blackcurrant is it is a berry fruit. I suppose at this point it's probably worthwhile actually explaining what that current is for people who who are listening, who might not know. Um, blackcurrant is a berry. Um, in the United States, you're probably very familiar with blueberries. Um, but but blackcurrant is is not as as prevalent in the United States. And that's because back in the 1900s, there was a federal ban on the, um, the growing of blackcurrant brushes because it had a fungus that attacked a certain type of tree that would then potentially affect, um, the United States wood availability. However, that ban in certain states and stuff, I believe is, is starting to be lifted. But the the key kind of part of the blackcurrant is it's a bit like blueberries. They they've got active ingredients in them that we're really interested in. And those are the polyphenols. And those are the molecules that provide anti-inflammatory. Antioxidant properties. But they are the molecules that give out our fruits and vegetables, typically those that vast variety of colors that we typically see. So, you know, blueberries, strawberries, blackberries they are all high in polyphenols. Another one then in blackcurrant that was specifically interested in is anthocyanins. And it's important to recognize that blueberries, blackcurrant, strawberries they all have anthocyanins in them. But there is different types of anthocyanins and there's different amounts. So blackcurrant has a very high concentration of anthocyanins in them. And all the research work that we've done has used blackcurrants from New Zealand. So um, I suppose if you speak to anybody that grows grapes for making wine, they'll probably tell you where those grapes are grown influences, the, uh, the taste, the flavor of the wine. Now, if in our example, we, as I've said, have used blackcurrants in New Zealand, and that's because, uh, New Zealand is exposed to very high levels of ultraviolet radiation from the sun. So essentially the anthocyanins are almost, uh, the solar protection, if you like, the, the sun cream for the blackcurrants. So they've got a high concentration of anthocyanins in them. Um, and that's what we've used in all our research work. Now kind of relating to your question about, you know, do take it and then take it again, or what are the kind of time course changes. Polyphenols in general have what's known as a general, a very poor bioavailability. To make the numbers easy. Let's say you consumed 100mg. You would not see all 100mg appear in the blood. You would see a lot of different metabolites. All of those metabolites would never necessarily always add up to the number 100. Some of it seems to disappear and go elsewhere. We don't quite know where, but it's those metabolites that we think are the, um, the causal reason why we tend to see these physiological responses. So those metabolites, they're only really present in the blood for sometimes a few hours. There are some papers that show that you might find the odd metabolite still around 12 or 24 hours later, but most of it tends to be gone quite quickly. And that probably relates to a lot of our dosing and duration response work. A lot of our work has been very applied in nature, so we've looked at different durations of intake, different doses of intake. Um, I've already talked a bit about dose, but the duration stuff, we've shown that people seem to need to take it for a few days to start seeing these, these beneficial effects. And if you say you've, you know, you've taken it just before a training session. And that was a very acute dose and you only took it one time. You may not want to say. See the benefits. You may not get the associated benefits that we've observed. We have shown an increase in exercise performance in a variety of different type, um, modalities, whether that be cycling or running. But again, they were all dosed for seven days. Um, and and the oxidation uh effects again uh, duration response papers have shown that again, you need to take it for seven days to see those benefits. It's not like caffeine where you can just stick it in. 90 minutes later you get the benefits. It seems to be something you need to take for a few days to to get that benefit. Now, whether that relates to the bioavailability of those polyphenols, some sort of accumulation. I don't have a good answer. We don't know. But it's it's, I think, an interesting future area of research that that will probably start to unpick that. Um, and you know what? What are the kind of causal reasons for why we see changes in station from blackcurrant? Why does it need to be seven days? Those are are very simple questions. But I get the sense the answer to those is going to be quite complex. Um, and, and we'll need a few studies to, to determine those. Yeah. No, that's that's great to hear. Kind of because like, with all this stuff, when we have something that's relatively new and promising, it's like we we have the answers to certain things and then a bunch of questions that we want to have the answer to that we have to wait for and or, you know, to a degree, we've got we've got evidence, I should say, versus answers. And the thing that so like based on kind of like what you've seen, it sounds like if someone is looking to implement that protocol there, they're better to worry about just getting on that seven day trajectory towards whatever event they want to manipulate with that input, versus worrying about reintroduction during the event so much. Um, maybe there's something there, but we don't have the answers to that yet. But we do know seven days seems to be a good a good protocol. So if your key workout or your key races seven days away, start seven start, start today and then do the seven days leading in. Yeah. I think it's also important to recognise as well that the blackcurrant supplement I've used in my research, it has been a spray dried powder if you like and it's encapsulated. Now the reason that's important. People eat fruits and vegetables as part of their diet, and polyphenols will be in those fruits and vegetables. But to get the kind of doses of anthocyanins that we're using, you almost need to eat an abnormal amount or a silly portion size, if you like, of blackcurrant, and that's going to come with it. Associated problems with things like fiber, potentially flavor of of the actual product and, and or availability of actually being able to, you know, buy that amount. Now, like, you know, supplements tend to work really well for that, whereby you can have a consistent dose, um, you can consume at any time of the year. Blackcurrants being a berry fruit, are known to grow in the, uh, the summer and late summer, especially in the UK and, you know, in, in January, for example, when it's winter months, you wouldn't be able to pick blackcurrants, so you wouldn't be able to eat them naturally. But if you're consuming it from a supplement type source, well, you then can get that. The dose of anthocyanins. As you say, you can dose it in the run up to races for the week or so before your event. Um, and you could do that any time of the year so that that's a benefit, uh, as a consumer to, to consuming or to taking blackcurrant supplements. Um, yeah, that's a great point. I think that that is the value of the concentrates that you can get from some of this stuff is, um, you know, fibre being something where there's, there's definitely benefits to fibre, but the threshold is such that if you go too heavy in it, you know, especially when we're talking about sport competition and things like that, you end up creating a bigger problem than potentially the solution you're going to make up for it with. Um, so yeah, we want to be mindful of that sort of stuff. Do, do you know by offhand like how much like maybe in weight, how many black currant berries would be required to get up to 200 anthocyanins if they were to just try to eat that much? And I think it depends on the variety where they grow and the sunlight stuff. You're saying to the concentration may vary? Yeah. The number I had in my my brain was about equivalent to about 80 blackcurrants. Okay. And I remember a time in my PhD, you know, I took garden peas. Frozen garden peas. They're similar size. And I ended up counting out 80, 80 of these things just to see what that would look like in terms of, like a portion size. And then when you say, well, that that's kind of potentially one capsule. So when you start doing two or 3 or 4 capsules in some of these studies, you look at that. I know I use garden peas, but it gives you an idea of the volume. It would be a lot of fruit to consume in one go, let alone over a period of a few days. And and that, I suppose, is, you know, the benefit, as we say, of, of concentrated versions of Of supplements. You only have to look at things like the beetroot juice research. If you had to try and consume the equivalent number of beetroot to get the the nitrate dose, you'd be consuming a lot of beetroot. Yeah. And that that comes with it again. Other challenges and the same would be true from blackcurrant. It's difficult to consume that amount. It is possible I presume you know with a bit of food processing if it's spray dried or freeze dried powders or even turned to juice, that then makes the consumption of those a lot easier for the individual. But we've all used blackcurrant capsules. Um, easy to consume, no taste. And, um, a lot of the work that we've done has been able to use placebos as well. So because they're in capsules, it's men sourcing and getting the same shot um, shape colour size. Placebo capsules being very easy. So that's um. That's what we've done in our work. Typically, yeah. Well, it's also interesting too because there's like there's other like friction points when it comes to looking at like just building it into your diet versus something as simple as taking a capsule or something like that to where one you have the bioavailability of whatever you're trying to get with that amount of fiber along for the ride it, you know, it's likely that you may reduce that in terms of like the it may not be something where you're getting the same viability as you increase that amount of fiber with it. Uh, the other thing I find really interesting about this topic in general is just I had, uh, doctor Mark Bubbs on for a series of episodes that's yet to be released, but one topic that came up was like, he works with a lot of professional athletes like, you know, NBA basketball players and, um, just like top tier athletes, where you would imagine, like everything is dialed. And he said, like when they get traveling and they have all these other things going on, like, you'd be surprised how easy it is for them to like, just start to like, make compromises on things. So the more friction you add to the process, the less sustainable people tend to be. So like if I'm sitting there and picking up, juicing, blending, pulverizing, whatever, like like tons and tons of black currants versus the pretty easy process of taking into capsules, I'm probably making less mistakes along the way in terms of just kind of not doing it because I run out of time, or I'm traveling and I don't have access to the blender the way I do at home and all these other things. I kind of go into it. So there's a lot to be considered with that, I suppose. It reminds me what you described there. It reminds me of that. Almost like a catch phrase. And I think I've seen this as a title of a paper as well, but it's, you know, a food first approach, but not food only. So, you know, you need to use supplements as and where you, uh, you can where there's evidence base to suggest that they work where they, you know, whether that's, you know, the timing total and type of those supplements, you know, in relation to, to performance and stuff to bring about the, uh, the outcome from whatever supplement it is that you want. And I suppose it's important as well that whatever supplement you are putting in place to whatever regime, whether that, as you say, is very tightly controlled, dialed in, there needs to be evidence that that supplement works. So essentially, you know, that that that's really kind of an important message, I suppose with athletes, you don't want to necessarily give them something that's going to be ugly and have a negative response on performance, recovery or health. It's got to be organic in some regard. Um, uh, with that regard, on on blackcurrant, I know we've focused a lot on, uh, fat oxidation, but we have seen other changes as well. I've mentioned a few studies that have looked at exercise performance. But we've also, um, done a bit of work on cardiovascular changes. So having a look at things like cardiac output or femoral artery diameter. So we were able to get people on a rig, get into an isometric contraction and then measure femoral artery diameter. So I suppose the message might be that it it's similar to beetroot in that it helps to increase blood flow and blood flow. What might be one of the associated mechanisms that are causing an increase in fat oxidation from from taking the blackcurrant. It's a possible mechanism, but there are probably others as well, due to some of the in the uptake of of metabolites and stuff downstream. So it it's not just a one physiological response supplement. We've seen, um, quite a few different physiological responses. Everything from um we've touched on it here as well. But, you know, gut issues and gut distress, uh, especially in the heat. Athletes tend to get a few more issues with gut distress, we've shown, or other research groups have shown that taking blackcurrant helps to reduce gut stress, and there's even been some work on recovery as well. If you think of a lot of the recovery supplements, your classic one is protein, but there is even some of the, you know, vitamin supplements, etc. people take to try and help with some of the oxidative damage that has occurred in exercise, and that that relates very much again, to some of the antioxidant mechanisms that you get from from blackcurrant. So we I think it's a really exciting time for blackcurrant research because it very much relates to this podcast where we've got changes in substrate use during exercise, but we've got cardiovascular changes. We've got some studies showing changes in exercise performance, but all of those studies have typically been done in young, fit, healthy individuals. There are some people that are known to struggle with things I've found. If you think of people who might be overweight or have obesity, people who've got type two diabetes, they're known to have altered fat oxidation. Insofar as it's not a benefit. It's not in a good place. It's not in a good state. I'd love to know what happens if you can give this supplement that's been shown to work in exercise with with young, fit, healthy individuals into those populations as well, and kind of take it into a kind of more clinical findings. Um, I think that could be quite an exciting future direction. Yeah. No, absolutely. It's yeah, there's a lot of moving parts with, with, uh, with the blackcurrants from, from my assessment. I think just looking at it, it was one of the reasons why I got curious about using it, because it's like there are a lot of supplements on the market, and eventually you have to kind of like ask yourself, what's the cost benefit of any of these things. So, you know, a lot of times when I consider whether I'm going to take one or not. Um, I'm looking at, well, is there. Is there one very small thing this is doing? Are there multiple things that are all directionally important for what I'm trying to do? So like some of your research and just the research in general around it, that kind of pointed to things like increased fat oxidation, increased blood flow, digestive things. These are these are three like relatively important contributors towards the things I'm going to experience on race day and then in training and things like that. So I thought, hey, this is probably something that's worth exploring a little bit more. Um, I did want to follow up though, on the on the digestive side of things is do we what do we know about the the driver there is that potentially the blood flow to just if you have better blood flow going into the digestive system, it's it's easing that process. Is there something else that we think is specific with blackcurrants that is helping with that process from just like an integrity standpoint in digestion or. Yeah. So this was not my research paper, but it was one of my research collaborators papers. Uh, I'm also not, uh, an expert in, in the gut, but as I understand it, especially in warm environments, athletes get a condition called a leaky gut. And essentially, it means that things start passing over the digestive, um, membranes in the gut a little bit more easily. And then that can lead to, uh, gastrointestinal distress, potentially at either end. And I don't know the underpinning mechanism, but the study that, uh, that I know of was, was taking people, um, through a protocol in a heat chamber and that it was that they were exposed to hot conditions with them without blackcurrant and measuring of gastrointestinal distress symptoms. And they showed that, that the blackcurrant reduced those symptoms. Um, as I said, again, I don't know that the mechanisms, but I suspect they are all interrelated, whether it's anti-inflammatory, antioxidant, uh, partial blood flow potential, upregulation of certain genes, etc. um, might, might all be contributing factors. Yeah. It's funny. It's like it seems like, um, as nice as it would be if there was, if there was just one major contributing factor to any of this stuff, it tends to often be multiple things. Or if there aren't multiple things all contributing, then the signal isn't great enough to be very important. So which just makes it more hard for you to kind of answer some of the questions that guys like. I have it. You know what, though? I think it makes it a very exciting time though for that research. You you've got a supplement that's relatively new. I mean, we started our work ten years ago and just over ten years ago actually now. But we you know, we started with some, you know, very basic exercise physiology studies. We looked at, you know, changes in the lactate curve. And again we showed that blackcurrant had a change in the lactate curve. That then led us to questions around substrate utilization. If there's changes in substrate utilization does that then have effects on exercise or endurance performance. So that's kind of our next natural steps. And then you start questioning and you get. You dive into the literature and you have a look at some of the other known physiological responses from polyphenols. So we then start looking at things like blood flow. And then it takes you off in so many different directions. And there are so many different, uh, studies that have been done now in, in different circumstances. As I said, Exxon's performance, um, some support in recovery, some. Um, looking at substrate utilization and and now actually when we look at 10 or 11 years down the line, we've now started to build up quite a body of literature. Um, some there's quite a few papers on, on, as I've said, substrate utilization. I definitely know of about 1516. A lot of those are in cohorts. Some are case studies. Um, but the future, I think, is going to be very exciting for, um, black currant and or anthocyanin research, because another simple question could be, well. You know, blueberries, cherries, strawberries these have all got anthocyanins. They've got different profiles of anthocyanins and different amounts. Can you get different physiological responses from taking different berries? Is there an optimal dose of each one to bring about different physiological responses? I don't know. I'm speculating, but I think it makes quite an exciting opportunity in the future for different directions. But but all I can talk about is really what we found now. Mhm. Yeah. No it's exciting. It'll be fun to see what, what comes out of all of it. When, when we continue to answer some of those questions. But um, Matt, I want to be sensitive of your time and the generosity you've given with explaining some of this stuff to me and diving into Fat ox and blackcurrants and all this sort of stuff. Um, but before I let you go, I did want to give you a chance to. If you have something else you want to chat about, or if not, where people can kind of find you, check into your research. If you have any websites or anything like that where people can kind of dive into that stuff. Yeah. No. Um, I'm available on the all, uh, the normal platforms. So ResearchGate, LinkedIn. You can you can find my profile quite easily from my, my university if you type. Matthew Cooke, University of Worcester, UK. Uh, you'll find my profile. It's got a list of all my, my publications. Uh, and, and on that that profile page of my university. It's also my, my contact details. And if there are academics out there listening or other people who are also interested, want advice, etc., who might be athletes, use my contact details, reach out. I'm happy to collaborate where, you know, there might be interesting case studies or, um, advice that I could give. Or even if you've got, uh, testimonials where you've taken something and it it shows to have worked. Um, you know, I love to hear those because it it's nice to get my findings outside of a research environment into an applied environment. So yeah, that that's where you can find me, uh, online, as it were. And uh, and my research and if people are desperate to read a paper, I'm happy to share those. Um, just reach out and I'm, I'm happy to share my, my work, but, uh. Yeah. Thank you also for having me. As I said, it was my first podcast. But, uh, hopefully, you know, the messages have been useful to the listeners and, uh, and getting the message out there as well about some of the work we're doing on Black Heron. Awesome. Yeah. No, my pleasure having you on. It was great. You sounded like a seasoned veteran to me. So, uh, props on that. Um, but I'll definitely I'll, I'll link that stuff to the show notes, too. So if listeners want to head over to some of that stuff, you can find links directly to it in the show notes and, uh, hopefully further the conversation for, for those who are interested. Great. Yeah. Thank you. Thank you for having me. Yeah, absolutely. Take care. Yeah. Cheers. Bye.