#43: Hydration Strategies, Sweat Rates and Cramping with Andy Blow

Really understanding that although there's, there is plenty of general rules when it comes to hydration, there are also some specifics where if you're doing stuff which is longer, if you're doing stuff which is hotter, you need to understand your physiology in order to get things really right for you and invest, invest the time in that investigation to get the best out of yourself.

Welcome to another episode of The Extra Mileage Show. My name is Floris Gierman, and on this podcast I speak with different experts, different athletes in the endurance sport space. We talk about ways to become a stronger, healthier, and happier athlete. And on today's podcast, I'm taking a deep dive into the topic of hydration with Andy Blow. He is a world-renowned expert in this field of hydration. He knows a tremendous amount about sweating, about hydration, about dehydration, and about cramping. And I think these are topics that many of you listening are quite familiar with. Andy He's also the co-founder of Precision Hydration, and this is a company that really dives into exactly figuring out your hydration needs specifically for you as a person, specifically for your training and racing conditions. Andy previously worked as a team sports scientist for the Benetton and the Renault Formula 1 teams, and he's an advisor to the Porsche Human Performance Center. Andy is an entrepreneur and he's a father of two young kids just like myself. That's something we just figured out that probably explains some of the restless nights that we both experience from time to time. In this conversation, we take a deep dive into hydration, into sweating, cramping, what unique specific approach personalized to take for your hydration needs, and much, much more. Andy was kind enough to set up a 15% discount code for anyone who wants to check out Precision Hydration, and you can go to their website and use the code Extramilest. So, um, yeah, check it out. Before we dive in, I would like to share that we offer two specific running coaching programs developed by me, Floris Gierman, and more information can be found at extramileus.com/training. There are many different ways that you can go about your training, and some athletes just like some additional guidance and structure to that training approach. And this is exactly where these training programs come in. They come with different base building schedules, anywhere from 2 to 10+ hours per week, and with race-specific schedules for beginners, for intermediate, and advanced runners. Reaching your running goals often comes down to the right race strategy for race day, the right mindset, nutritional approach, stress management, and so much more. And that is what these programs are all about. And especially in these uncertain times when often training schedules change and race plans change, these schedules are very flexible and totally make you feel in control of your own training. More information about these programs can be found at 5ktohalfmarathon.com or marathonprprogram.com. And these come with lifetime access, so you purchase it once as an investment and then you can keep using it over and over again. If you have any questions at all about these programs, just shoot me an email. Without further ado, I hope you enjoy my conversation with Andy Blow. Andy, I'm excited to take a deep dive with you in the world of hydration. It's great to have you here on the Extra Mileage Show. Welcome.

Good to be here, Flo. How you doing?

Doing good, doing good. Many of the listeners have some type of experience with challenges in their race performance and in some of their training, whether it is bonking, cramping, hitting the wall, overheating. When doing the research for this conversation, I listened to a few other podcasts and I did some more of background reading on you, and I definitely noticed that you have had certain challenges as well. You've even ended up in the medical tent a few times. Can you talk a bit more about your athletic background and how you got into the world of nutrition— oh, sorry, hydration?

Yeah, for sure. You, you've, you've hit all the nails on the head there, because if it's like bonking or cramping or dehydration or hyponatremia, I've, I've done most of them in, in my career for sure. Um, learned a lot of things the hard way. You know, in as an endurance athlete, which is sometimes the best way, but sometimes it's nice to now be able to help people shortcut that and not, not do anything quite as bad. But yeah, the, the sort of what, what I learned about hydration came out of a big personal frustration with not being able to complete long hot events at the, at the level that, that I, I knew I could. It was mainly triathlons for me, but I also did a lot of long-distance running, a lot of cycling events, and, um, yeah, always temperature was cold, I was great. If it got hot and if it got humid, I'd fall apart. And it was, it was years of trial and error to unpick the puzzle.

Yeah. And, and, and then eventually, I think it was even that you had, you were training often in the UK, but then making it out to Kona, for example, for the World Champion Ironman, and there you start experiencing trouble as well. Is that right?

Yeah, that was one of the, that was one of the ones that really was a big disappointment for me because as a youngster, as a triathlete growing up in the '90s, watching Dave Scott, Mark Allen, and all these other great triathletes in Kona, that was what I wanted to do at some point. And I qualified eventually and then got to go and had a horrible experience like competing in that race. And so there was an element of overtraining going into the race for sure, But a big part of it was hydration, and I was just, I got my intake all wrong, as I'd done a lot of times in the heat, because I was a guy, I sweat a lot, I have a big sweat rate, I'm not particularly big, I weigh about, when I was racing, just under 70 kilos, so like 145, 150 pounds, but I can sweat 2 liters an hour quite easily. So I always knew I kind of had to drink quite a lot of fluid to compensate. But understanding the electrolyte balance side of the equation was, it was really difficult for me to, to get my head around. And as it turned out, a friend of mine who was a doctor noticed the problems I was having with cramping, with hyponatremia, which is, which can be signs of heavy, heavy electrolyte loss. And eventually I basically had a sweat test done, which is where they take a sweat sample and measure the sodium content. Mine was really high. So coupled with a high sweat rate and long events, I was just not adequately replacing what I was losing. That was kind of when the light bulb went on. Because after that, once I got my head around that, I could experiment in the right zone and start to perform in the heat. It was a big change.

In what sort of way did that experimentation go? I'm super excited about this, by the way. We're going to dive deep into the sweat test you mentioned earlier and several of these other topics, but many questions already come up here. In what sort of way did you start testing and experimenting with that?

Well, the, the guy that helped me sort of identify this problem was a surgeon called Dr. Raj Jutley, and he's a heart surgeon. I got to know him professionally through working with motor racing drivers because at the time I was also, as well as being a triathlete, I was working with motor racing teams doing fitness training for the drivers. And we got chatting about this, and, and obviously as a heart surgeon he has a really deep understanding of the cardiovascular system and also of electrolytes and blood volume. And he said to me, look, all the problems that you're exhibiting look like they're from this loss of salt rather than just out-and-out loss of fluid. So his advice to me was to really turn up the dial on the amount of salt or the amount of sodium that I was taking in whilst not necessarily increasing the amount of fluid because I was taking on so much I was washing my body out. And so he essentially gave me some numbers which at the time was between around just over 1,000 milligrams of sodium per hour to take in events, which if you read the common literature, there's a lot of different ranges out there, but a lot of the recommendations are quite a bit lower than that for the average person. And his advice was like, turn the dial up and see what happens. So that's what I did. And it was like that. It was fantastic. For me, it was the answer, you know, and, and that made me quite evangelical about that for quite some time.

Yeah, no, I can imagine it really is like once you come across something like that, that can make that much of a difference just by your hydration and your salt intake. I can imagine that. Yeah, you want to almost go out there and tell more people about it in a way. So, so let's take a step back for a little bit because you mentioned you're a heavy sweater. What are some of like, I know there's many variables involved between heat and between gender and that can be like body size, whatnot, like, if you could still kind of give some ranges of what, what would a light sweater look like, what would a moderate, and what would a heavy sweater look like, both in like how much fluid they're losing but also how much salt they're losing?

Yeah, well, it's a really good place to start because understanding the magnitude of fluid loss and understanding the magnitude of electrolyte loss is, you know, a great angle to come at hydration. Problems from, because below a certain level, when you start exercising, as long as you're pretty well hydrated, you can lose quite a bit of sodium, quite a bit of fluid without experiencing problems. And it's that everyone's thresholds are different, but there becomes a certain point where a level of drop-off becomes problematic. And when we talk about like sweat rates and sodium composition in sweat, there's big, big variances between people. So the extreme ends, when you've got someone who's working really hard in a hot environment, and they're doing a run or a bike ride or something, and their metabolic rate's really high, then a low sweat rate would be, let's say, 500 milliliters per hour. So 16 ounces of sweat an hour might be low for when you're working hard. Obviously, if you're not working hard, your sweat rate can be virtually zero. What we're interested in is when people are pushing it. But then you take someone else who's working really, really hard, who's maybe a bit physically bigger, has more muscle mass, and just has a higher sweat rate. We can easily see sweat rates in endurance athletes of 2, 2.5 liters an hour. And in big athletes, like I've worked with NBA players and NFL football players who lose 3 liters or more per hour. Wow. So that range is massive. An average, if, you know, averages are always a bit odd to talk about because people get obsessed with what's in the middle, but But if we do talk about averages for a minute, it's probably about 1, 1.2 liters an hour for an endurance athlete working quite hard. But, you know, you could be half that, you could be 2 or 3 times that. And then with sodium loss, sodium in sweat is— you get— you have a lot of sodium in sweat because sweat comes from your blood plasma and your blood is very salty. And blood has 3,600 milligrams of sodium in every liter. So it's super salty. Sweat can be as dilute as 200 milligrams of sodium per liter, so that, that's really light sweat. And really salty sweat could be 2,000 milligrams per liter or more, so kind of a tenfold difference. And I was about— whenever I get measured, and I'm probably the most sweat-tested person in the world now because of what we do for a living, but my levels are usually about 1,800 mg per liter, and the average there is 900, 950 mg per liter. So I'm kind of like 2 times the average.

Yeah, yeah. So if I understand it right, like, if you— hi— if you get dehydrated during exercise, like, your blood gets thicker and the total blood volume is reduced. Is it correct to assume then that this increases your heart rate during exercise as well?

Yeah, it's a big factor. The cardiovascular drift, it's called, when you get— when you're exercising in the heat, runners will see it classically. If you run on a treadmill, especially at very controlled speed for an hour, your heart rate will just drift upwards throughout that time as you get hot, because your body— your blood has to— your heart has to work harder to pump blood to the extremities to cool you down. At the same time, if you're not drinking a lot, where your blood volume is contracting, so you kind of get that increase in heart rate. And later on, you probably get that increase in perception of effort because of this cardiovascular drift. So it's fundamentally the problem with— when you boil it down, that is the problem with dehydration for endurance athletes, is contracting blood volume.

It has been interesting. I saw a few graphs through like the Road Runner, like RCA, and it showed actual like an athlete over time when they were or were not drinking, and they were, they were looking at body temperature. And you see it quite similar at the beginning, like 30 minutes in, 45, you start seeing that line go wider and wider. And then like an hour and a half in, 2 hours in, it's like a 2-degree Celsius body temperature almost between drinking and not drinking, which I thought was, was quite fascinating right there. So, so there's, there's a few thought processes about hydration and that has changed significantly over the years as well. Between the early years saying like, don't hydrate during a marathon to like, drink as much as you can. And then there's drink into thirst? Like, what are your thought processes? Obviously you've, you've taken a deep dive into hydration for many years now. What, what are your thoughts here?

Well, yeah, you, you've identified that sort of like extreme paradigm shift that happened between athletes. You used to be advised, if you're doing a marathon or anything, don't drink at all because it— you can't digest it, it will influence your performance. And then, yeah, in the, in the '80s, the '90s in particular, the early 2000s when I was competing, it it was very much so presented as, oh, dehydration is what's gonna get you, so you need to drink. And there was no kind of upper limit on that, it was just like, drink as much as you can. And a lot of athletes did that and found that it's quite problematic in its own right. But then, yeah, we've started to shift more towards the middle ground. There's quite this in vogue statement at the moment, it's like, drink to thirst, so listen to your body. And on one hand, I'm quite an advocate for that because I do think that endurance athletes, when you get to know your body and you get to listen to the cues that are presenting to you, drinking when you're thirsty can be a sensible approach. You know, you can, you can certainly monitor, and you won't— you definitely won't sort of go get horribly hampered by dehydration if you drink when you're thirsty. Whether you'll optimize your performance though is another, another matter, because when your sweat rate's really high for a compressed amount of time, it is possible to get relatively rapidly dehydrated You know, and when you're racing and it's stressful and you've got other things to think about, like monitoring thirst as the only symptom is not always so good. So I think this is kind of what we try and work on with athletes is like a blended approach. Sometimes there'll be situations where we, we weigh everything up and, you know, Flo, if you're going to run half marathon in the winter, cool weather, you don't need a hydration plan for that. You know, you, you hydrate before, you might take a drink, a cup from an aid station on the way if, if you need it, but, and then you rehydrate after. But if you're going up and doing a 50K ultra in the heat of summer, I think you need more of a plan, you know. And, and it's not a plan that you stick to rigidly, but we talk a lot about guardrails. So we would talk about like you understanding roughly what is your sweat rate, roughly how much sodium you're losing, and then Putting in place some parameters like, okay, each hour I want to hit roughly one bottle with X amount of sodium in it, or one bottle of this and one bottle of water, or whatever it is, so that you at least— you might change that plan on the fly based on how you're feeling, because if you are thirsty you might drink more. If you feel real bloated and you're peeing a lot, you might drink less. But you kind of have some kind of guardrails, because otherwise, if you just leave it to chance on the day, for a lot of athletes, that's, that's not going to work in a long event.

Yeah.

Yeah.

So, so, so many questions spin off of this, and I want to, I want to even figure out where to, where to step back to from here, because I do think it's good actually for the audience listening to, to hear a bit more about, all right, you as an athlete went through all of these different challenges in your own journey, and from there on you decided to start Precision Hydration. Can you, can you talk a bit more about how you educated yourself on, on the field of hydration? You have a degree, um, in this field as well, in sports science. Um, like, how did that whole journey go and what are some of your, your key learnings along the way there?

Yeah, that is interesting because when I started looking into this, I couldn't find out a lot of information beyond the very generic information that was out there about how to hydrate for endurance. At the time, as I said, late '90s, early 2000s, a lot of it was just about drinking more. It was very focused on the volume of fluid that you got in compared to how much body weight you were losing. Once I got talking to Dr. Juttley and he put me down this route of looking at sodium loss in particular, what I did find was on the internet, I found in the dial-up days when I had to sit listening to the modem clicking away, I'd go into ultra running chat rooms. Was the place. Yeah, those. And there were these guys that were running when it was in more of a niche sport, people running 100 milers and 100Ks and things like that. And they were bumping up against this problem of extreme electrolyte loss as well. And I was reading the stuff they were writing and it was resonating with me, and I was trying it and it was working along with the sweat test. And I thought at that point I was working as a sports scientist, I was coaching some athletes, I was working in a lab, and I thought we should add this sweat test. So the sweat composition test should be a test that we do in the lab, which was kind of the first step down the Precision Hydration road. And at that point, I viewed it as maybe just a little service from our lab, something to test athletes and educate them on what I'd learned, because I felt that that might— whilst it wasn't going to unlock the key to performance for everyone, it certainly could be for some people. But the deeper we got into it, the more people we tested, we thought this is really quite impactful in lots of different scenarios. And so PH kind of grew out of that. It started off as a niche consultancy for hydration, and then we've, we've expanded that. And, and eventually, as well as offering sweat testing now, we also have a range of products. So, you know, because We were advising people how much sodium to take in, but there wasn't, and still isn't really outside of our range, a really good market of products that come in different strengths for different purposes. Everyone focuses in sports drinks, everyone focuses on, you know, content, carbohydrate content or electrolyte content and flavor and kind of generic claims of performance without trying to fit them to an individual. So that was That was where Precision Hydration became, I think, a bit of a different concept. And, and our journey for the last 10 years or so when we've been growing the business has been primarily focused on like education first for athletes. And if the education is useful, then we have a toolkit of tests and products and things that can follow on in order to, you know, facilitate actual trial and error in the field. Yeah.

From an educational perspective, you guys are killing it, man. Absolutely. Like, seriously, on your website alone, you already have 90 articles plus about hydration, deep dives, and then, like, your Training Peak course about hydration. Really good. I can highly recommend it. Talk to me a bit more about the sweat test that you guys have on your website and, like, for ways for athletes listening, just figuring out what is their optimal, like, approach to it., hydration?

Yeah, we've— so we started out with this physical sweat test, which we still do, which is now called the advanced sweat test. And what that is, that is one where we put electrodes on your arm, we stimulate the sweat glands, collect some sweat, and analyze it. And that's kind of the gold standard because that allows us to really actually measure what's in your sweat and advise you on how that might impact your hydration strategy directly. But what we also recognize is that although a lot of keen athletes will go somewhere to have a sweat test, that's quite a difficult thing to do. You have to physically be near a center, you have to pay some money and go and do it. So we developed an algorithm behind a questionnaire on our website where you can answer some questions about the duration of the type of sport you're doing, the duration of the activity. It asks you questions about historically, have you had cramps? Have you seen white salt marks on your skin? Do you think you lose a lot of salt in your sweat or not? Because surprisingly, when we've analyzed the results,— when we test someone's sweat, if they do lose high amounts, quite often if they're an experienced athlete, they intuitively know it. And if you can tease that information out in the right questions, then you can at least put them in the right ballpark. Because one of the ironies, I guess, is that we are precision hydration, but the level of precision required to get your hydration right is not— we always say it's not like hitting a bullseye. It's like hitting a barn door. You just have to get it about right. And when, when it goes wrong for people is when they've really missed the target by a long way. So we try to get you into— if it was a t-shirt, we try and get you into a small, a medium, a large, or an extra large, not into a tailor-made outfit, you know. And that's what the questionnaire-based test does.

So it's a great place for people to start. Yeah. Well, and the challenging part sometimes with all of this too, is there are so many different variables involved, right? Like, not just from a personal perspective, but even from a race, like whether you're racing in, in colder weather or hotter weather, whether you're racing for 2 hours or 10 hours or more. Like, there's a lot of different variables involved. I want to talk a little bit more. So if people listening here would want to dial in their nutrition, I'll make sure to obviously link to your sweat test. Um, I've also heard you talk about some things you can do with a weight scale, standing on it, measuring, going out, uh, measuring afterwards again. Can you talk a little bit more about that part too?

Yeah, that's, that's like what a lot of people would know as the classic sweat test, like the sweat rate test. And the, the way that works is for every, um, liter of sweat you lose, about 32 ounces, you lose 1 kilogram of body weight or 2.2 pounds of body weight. Because that's, it's a rough guide and it's not an exact science, but basically if you go out for a run and you lose like 2 kilos, 4.4 pounds, you know that you've lost about 2 liters of sweat, roughly speaking. And so by weighing yourself before and after key training sessions, you can start to build up a bit of a database in your head or even an actual database on a spreadsheet of how much sweat you lose. And so we've got a blog on our site where people can download a free Excel spreadsheet, pre-formatted, so you can put in your weight before and after training sessions. You can even put in the amount that you've drunk in case you've had a drink during the session, 'cause that will then correct for that number. And it spits out a sweat rate in different conditions. And I've heard this, the idea of sweat rate testing is sort of a bit controversial in sports science, because there's people that advocate quite hard for it,, and there's people that attack it as being unnecessary and, you know, kind of over-engineered or a waste of time because you don't really learn so much from it. But I always think that it shouldn't be viewed as like an absolute number, an absolute tool that we— we're not using this for a high level of intricacy. We're using this to do it. If you do this a lot of times, you start to build up a picture. If you're a guy who loses about 1 or 2 kilos in an hour run, or are you 3 or 4, which would be on the heavy side, or are you less than 1? And if— because if you do it in lots of conditions, you, you just get better at figuring out what that level of loss is. You can then compare it to thinking back, how did I perform? Yeah, I didn't feel so great after that one. It took me ages to recover. Try drinking a bit more, or a bit less in fact, and seeing how that— and it's another variable to play around with. And what you said before, you know, about complexity is so true because whilst the big variables here are obvious, like the amount that you sweat, the amount of salt that you lose, the duration of activity, the variables involved in that equation when you zoom out are massive because the environment's always different, the pace is always different, the clothing might be different, the actual hydration status, the amount of fluid and sodium you've got on board in your body when you start is often different. And when you're dealing with any systems or any situations that are highly, highly complex, it's impossible to measure every variable and nail it down and have an exact prescription. So what you end up doing is— but that doesn't mean you just then don't try and measure anything and throw it out. You use these best guesses by doing a little bit of data collection. And then I use this phrase a lot. It is trial and error. Then. But it's trial and error around the set point, you know. Like, I'm sure for, for running, a huge one that's, that's quite similar for this is pace judgment. Because you can do all these formulas to calculate, I've run 5K in this time and I should be able to run 10 miles or half marathon this time. But you have to go out, you have to try this in training, like measuring your pace, seeing how you feel, and dialing it in. And one day, you know, I ran, I ran exactly the same route the last two mornings here for training And my average pace on yesterday's run, I think, was like 4:34 per kilometer. And the average pace today was like 4:15 per kilometer. But I felt better, you know, like I was running harder yesterday.

And it's just day-to-day variance. Yeah, it is. Like, we often talk about a MAF test where you run on a, on a track for— you warm up for 15 minutes and you run at the same heart rate and you look what your mile split is and what the drop-off per mile is. And even there you can do it 2 days in a row. And although the conditions might be the same with the wind and temperatures and all that, like you can sometimes notice a difference right there, 20 seconds, 30 seconds. It's, it's sometimes unexplainable too, whether it is sleep or some of the stress levels in the back of your mind. That's just so many different variables involved there too.

You know about that with the— you've got, you've got kids as well. I've got, I've got kids. My kids got me up at 5 o'clock, 5 AM this morning, you know, and that's not, that's not a great way to start when you want to get, get out, get out for a run. But maybe that's a little bit why my performance today was a bit more, you know, it felt worse. But yeah, you don't know. And, and I think that's with hydration, people have often— where, where the industry has gone wrong in, in the past is to try to be, to try to be overly prescriptive. And then what's happened is people have kicked back against that and said, oh, you should just listen to your body and just go with thirst, it's all natural. And yeah, as a sort of antidote to this excess prescription. And, and somewhere in the middle of that is a good blend of, yeah, we're going to listen to our body and we're going to be instinctive and all this, but it doesn't mean we don't have to have a bit of a plan and a bit of a framework to work within because there's no harm in having these kind of rough guidelines and understanding. And, you know, we often extend it out further than hydration and say, look, for any endurance athlete who's doing a long event, there's kind of 3 things you should really, really know. Apart from— there's a 4th one, which is how fast you can go. So your pacing is really important. But the 3 things is like, look, how many calories or how much carbohydrate would I need per hour really to, to keep going through this? At the pace I want to go? How much fluid, you know, in liters per hour or milliliters per hour? And if it's hot or if I lose a lot of sweat and salt, how much salt? And if you can get those 3 things, excuse me, about right, and you get your pacing about right, there's not a lot else that can really, really upset you, you know. And so when you strip away all of the BS that's out there, you know, those things. Yes, there's always other things going on. You can pull a muscle, twist an ankle, your shoe can fall apart, whatever. But, but you get your pacing right, that's huge. That's probably the number one performance determinant in endurance sport. Then you get your calories, your fluids, and your salts right, you're gonna have a great day. And, and yeah, that's, that's the thing. A lot of what our— that's what over the years, that's a big part of what our messaging has become. Is like focusing on, and we're really zeroing in on helping people get that fluid electrolyte piece right.

Yeah. So, so stepping back for, for a bit here, let's say you're working with an athlete and you would have to determine like what is the optimal race day hydration strategy. So, so what high level would that look like pre-race, mid-race, and post-race?

Yeah, we talk a lot pre-race about, about just normal hydration in the days building up, making sure that you're not overdoing the hydration because there's a big temptation to be sat with your big water bottle like sipping away the whole time. You probably do want to be prudent and take on a little bit of extra water in the days leading up, especially if you're traveling to the event and all those sort of things, but you don't have to go crazy because that's a big that's a big problem for athletes, over-consuming water and diluting their bodies beforehand. If it's a big race, a hard race, or a hot race, or you're someone who suffers with hydration, one thing that I always do and we encourage athletes to do is to preload with a strong electrolyte drink in the hours before. So rather than just drinking water, you'd have like 16 ounces, 500 milliliters of a very, very strong electrolyte drink. We have one that's 1,500 milligrams per liter, which is is kind of a good strength for that. Yeah, there you go. Yeah, right on cue. And that's kind of like 3 times stronger than a regular sports drink, so it, it helps your body to— the sodium goes into the bloodstream, helps you hold on to a bit more of it, so you're not just one of those people in the queue for the, for the Portaloos at the start. So that's, that's generally a pretty standard buildup. To get you to the line optimally hydrated, not having overdone it, but also not having underdone it. Once the race gets underway, that's where it kind of all blows apart, and, you know, take 10 people and there'll be 10 different approaches. But the one thing that is true for everyone is we're not ever trying to meet people's needs like for like. So if you sweat, if we calculate you're going to sweat about 2 litres per hour and 1,000 milligrams of sodium, we're not trying to put 2 litres of fluid and 1,000 milligrams of sodium back in. There's an upper limit to what your system can absorb, and it will vary even for the same person. It will vary based on pace and on the mode of exercise. So we all know it's a lot easier to drink more on the bike than it is running, both for logistical reasons and for the fact that you're not sort of bouncing around. So you might accept a low— a more of a degree of dehydration when you're running than when you're cycling, for instance. And, and really what it comes down to is then, okay, does— so if we're not replacing 100%, at the lower end we could be replacing zero, because if the event's short enough or the conditions are cool enough that we don't need to drink, then ideally we won't. You'll often see top runners not taking a drink at all, even during a half marathon. Very rarely in the old days— now this wouldn't be recommended now, but people did used to run marathons marathons on no drinks and no food. I have heard similar stories. Yeah, yeah. And, and some decent times, some impressive times. I don't think— I think that's more of a demonstrating what's possible rather than what's optimal. But, you know, we would always say, but half marathon for faster runners could well be a distance where you don't consume anything. But then once we get into this zone of, okay, well, like, how long's the race? How long are you gonna be out there? What's What's your pace like? That's where it gets a bit interesting as to at what point do we need to start to replace some element of what we're losing. And essentially we just try and build it out from there and then put a bit of, a bit of science goes into that, quite a lot of science and measurement, but also a good amount of intuition and practice. Because we know that, for instance, most people are going to struggle to absorb more than 1 liter per hour. We do have a few athletes that can drink a bit more, especially on the bike, but I don't know many marathon runners who can drink a liter an hour. You know, that's a lot of drinking. Yeah, it's a lot to take in. And so it tends to be sort of, you know, a little bit case by case. We, we look at what the, the upper and lower limits are. And if— and really, for, for moderate distances, you know, up to marathon, that kind of thing, you're looking to take in the minimum you can to a degree. To get you to the finish line in great shape. When you get into ultra distance territory, you're often drinking a bit more early on in order to mitigate the drop-off that's gonna happen later. And then again, but you've got so many more variables into that because ultras often start in the morning, you go through, it's cold, you then go through the heat of the day and then you go back into the cool again, so sweat rates vary and just trying to compute that, a lot of the time you spend like iterating on past experience and just sort of, as I say, getting these guardrails in place though is the key. So it's understanding that, okay, Flo, you generally perform well on 500 to 700 mils an hour, and then you can start to think in this event, well, I've only had 300 mils in the last hour, that's probably why I'm getting a bit thirsty, I need to up it in the next hour to get back on track, or vice versa.

Yeah, and, and to be straight up, for me it is all often been a lot of guesswork. And like you were talking about earlier too, like a lot— like, yeah, right now you've mentioned a few different tests that you can do, but indeed, like, the trial and error gets you to fine-tune it for your specific situation. And not every race is alike as well. The one part that has worked for me in the past is taking some salt tablets throughout a race indeed, and not waiting until the latest stages of the race either. Even there, starting to consume it somewhat towards the earlier stages, because once you start noticing some of these signs, and, and this is kind of to play on what you were talking about earlier too, like, yeah, you can drink to thirst, but once indeed that intensity is that high, sometimes those signals come later than when you truly, uh, should be fueling up. And, and sometimes when I even look at myself of I'm really good at estimating what perceived heart rate I'm running at, at a lower intensity. However, once there's hills involved, once there's altitude involved, once there's heat, cardiac drift after 2 hours, some of these things just kind of goes out of the window at that point. And yeah, having somewhat of a plan in place for that when you can still think clear versus in the later stages, you might not. I've come to later stages in a race where I simply forget to hydrate or forget to eat. And that's when indeed when you, when you get in trouble, it's hard to make up for that.

Yeah, I think you, you definitely, when you start to notice, if you're doing a very long race, you might start, your mood starts to go and your motivation to keep pushing. I've definitely had races where you just kind of, you start, I'm not gonna, I'm not eating anymore, I'm not drinking anymore, and just, I just want to get to the finish, you know, and you sort of make slightly irrational type decisions just because you're the psychology of it plays in. If you've got a bit of a rigid plan, and that's where in the really long races, I think it's one of the reasons why a lot of the ultras, you know, traditionally had pacers and things in the last half and whatnot, is to keep people safe by not only making sure they don't get lost and things, but make sure they keep eating, make sure they keep drinking, you know, make sure that— because you do kind of, you shut down, you, you can't be trusted with your own, your own safety at that point. So it helps to have, you know, support crew and who know you and, you know, sort of getting the right things to you at the right time.

Yeah, and there's something to be said about the alarm on your watch as well. At a certain point, at least for me, it has worked well to kind of remind myself of hydration and nutrition.

Yeah, that's— that is a big one actually, because that's what we always used to do in an Ironman, have a beeper on your watch, you know, beep every 20 minutes on the bike. And Sometimes you would get criticism, oh, well, you don't know that you always need to eat every 20 minutes. It's like, fine, because you might evaluate yourself at that point and go, you know, I still feel a bit sick, a bit full. I only ate 20 minutes ago. I'm going to leave it now. But at least, yeah, it stimulates that thought process. Like, do I need something or should I have something now?

Yeah. So we often talk about hydration in the heat and the importance of that, yet we don't really talk much about it in colder weather. And I think especially now going into winter and colder months here, Let's talk about that a bit more. And so obviously the hydration needs change, but, but even one mistake I often see runners make is overdressing, wearing way too many layers, not just in training but even in racing. Can you talk a bit more about hydration during colder weather and also how actual clothing can impact some of your hydration needs?

Yeah, you very often see that in cycling I did some, many years ago, I went and did quite a lot of cross-country skiing, and it's, they're the kind of activities where you kind of have to dress up relatively warm because of the speed you're moving at, the airflow. But when you're working hard going uphill or something like that, you can really sweat heavily. So it is true, it's not true to say that hydration needs are as extravagant in the winter as they are in the summer, because clearly we're going to sweat more when the sun's out, when it's humid as well. But in the winter, if you overdress, you can get yourself into a bit of hydration bother. And the other thing is that in the very cold, you get this thing called cold diuresis, which makes you pee more. So, you know, and that's what we see with, especially with open water swimmers and people that are doing stuff where they jump in, where you go in cold water, you pee quite a lot because the blood volume moves to the core of the body. So your, your pressure receptors and your kidneys read the fact that you've got kind of more fluid on board, then you have dumped fluid to bring your blood pressure down. And actually you end up dehydrating not through sweating, but through peeing. In the wetsuit?

Yeah.

In the wetsuit. Yeah. Or if you're out, you know, that can happen in extremes on a cold day on the bike, if extremities get cold and whatnot. But yeah. I think the other thing about winter training as well, it perhaps is a little bit less applicable to pure runners than cyclists, but if you end up doing a lot of indoor training, that is sweaty as anything, and making sure that you're getting adequate hydration. I've been jumping between, in the winter recently, going outside and still running, but sitting on my bike in the shed at home sweating away, and I definitely, 45 minutes on my Wattbike, I'll drink at least half a liter of water or a light electrolyte drink. Whereas if I went out and ran for 45 minutes that day, I'll drink nothing, you know, except for before and after. So just because of that, you know, it's dripping off me by the end.

Yeah. So one topic that comes quite often and comes up quite often is intermittent fasting and fasted runs and how to some extent the fat burning abilities are trainable. If you do occasional runs fasted, yeah, at the beginning you might be able to do it for 30 minutes and feel the need to pop a gel if you've always been popping gels. Yet if you, if you built that up over time, sometimes like you can go out much longer. How trainable is it with hydration from that perspective? I'm just curious because I see it to some extent like working in, in the nutrition fields, but just curious about the hydration field for that.

Yeah, I think it's less— it's definitely— there's less room for maneuver on that with the body to adapt to dehydration. So it's rare that you hear anyone these days talking about, you know, training, purposefully training dehydrated to adapt. I'm sure that— and I don't know if I've read any— I don't know that I have read any specific papers on it, but You would assume that the body is really good at adapting to stress that it's put under, so there might be a minor adaptive response to improve training if dehydrated to a small extent. But I think the common wisdom is definitely that any benefit is outweighed by the negatives of how difficult training is dehydrated, how potentially damaging it is. Is not normally something which is recommended because if you've ever got dehydrated in a training session and not had access to fluids, you know how terrible it can feel. You know, and it makes you— I get it can make your muscles feel really sore, it can make— it certainly slows your pace, you get headaches, you just feel lousy. It's like a horrid— it's even, I would say, it's even worse than— excuse me— than that experience of like a bonk or running out of sugar because at least that's quickly fixed with a bit of sugar. Whereas when you get properly dehydrated in a run, the recovery can be 2 days from that because you've really run your tanks dry and it takes time to rehydrate at a cellular level.

So basically, like, training dehydrated is not something that would be recommended, and indeed, to that extent, quite dangerous as well. And it can, can really lead— like, just the overheating part and, and the different risks associated with it Yeah, it's this fine line between dehydration and hypernatremia from that extent. Can you briefly, because I do think it's important to talk about hyponatremia, um, just about high level, the risk and some of the symptoms and how you can avoid that part as well?

Yeah, so hyponatremia was identified in sport in the, started I guess mainly in the '90s, 2000s with people being encouraged to drink more and then overdrinking to the point where hypo is low. Natriemia is the salt level in your blood or the sodium level in your blood. So it's a dilution of the salt levels in your blood. And what it does is it forces fluid from the bloodstream. Normally when you drink too much, you just pee it out. But when you're exercising, you drink too much, you can't pee as much. So the water gets absorbed into the body and it gets pushed from the bloodstream into into the body cells and they swell up. And that causes puffy fingers and puffy ankles, but it also can cause swelling in the brain, which can at the extremes be fatal. And you sort of see, you know, still a handful of deaths every year from hyponatremia in big sporting events. So although it's not something that people should go out every day and be afraid of, you know, they should still drink, you know, to prevent dehydration. Overdrinking and hyponatremia is is that other end of the risk. And I know from, you know, hard-won personal experience how horrible that is, because it makes you feel— when you get hyponatremia, you feel very lethargic, you feel very— you can feel quite disoriented. You can sort of get a really dry mouth, weirdly. That's— but a dry mouth that's not— you can't satiate your thirst by drinking water, it just gets worse. You can get muscle cramps, quite often and just this horrible fatigue and loss in power and output that feels a bit like when you run low on sugar, but you don't get that same craving for sugar and that sort of satisfaction of eating something. It just doesn't help.

What you need is salt at that point. There are a lot of similarities in those symptoms you just described between hyponatremia and dehydration as well, from the disorientation and the cramping.

And yeah, that's one of the problems with it. It's been commonly misdiagnosed in the past because everyone sees a marathon runner collapsing near the end of a race and thinks, oh, it must be dehydration. And it could be, but it is— if, if you don't look into it deeply enough, it could be that they've overdrunk and they're becoming hyponatremic. And, and that's where I think race doctors and, and medics and people have become better over the years at identifying that because it's been starting to become a lot better highlighted.

I do want to transition for a little bit towards the topic of everyday nutrition or hydration, because obviously, yes, we can do so much during training, we can do so much during racing, but there's 23 more hours in the day often. Can you, can you explain? Obviously, once again, it's very, very athlete-dependent, very person-dependent, but how can a person best go about hydration during the day?

Well, one of the big things I've become better at since, you know, learning more about this is, is kind of reducing the friction in it. And genuinely, I sit around with a bottle close by most of the time, which I do— there you go. I think it's a good, a good habit. Not because I don't have a target to drink X amount of these a day or anything like that, but if it's there near my desk when I'm working and stuff, if I feel a bit thirsty, I can drink. And I don't have to— because when you get involved, especially because a lot of us nowadays, if we're doing kind of computer work, quite deep work, you can get quite zoned in and just forget. So just the simple act of like making it available, nice bottle that you like drinking from, nice cold water or whatever you want to have in there.

I actually brought a vase too. I got so sick and tired of like the small glasses. I ended up bringing a vase and it fits more than a liter in it, so yeah, I got some vases here.

You never have to leave the desk. You can just keep working. So that's one. And then people have lots of different opinions on caffeine, but I think definitely caffeine affects people in different ways. I've learned that if I have to stop drinking coffee after a couple, 2 or 3 cups in the morning usually. It doesn't do me many favors in the afternoon and it certainly, as well as my energy, it affects my hydration status because it is a diuretic. And although there are studies that show that your net fluid loss or the net fluid balance from drinking coffee is probably neutral or you still retain more than you pee out, I'm not convinced for everyone that that's the case. And for me, I sort of limit my caffeine intake these days. Interestingly, I mean, I'm I'm 42 years old now and I wouldn't have said that 15 years ago. I could drink coffee as much as I liked and I think that's maybe partly metabolism and aging and that sort of thing. But I also know people who appear to exist pretty much indefinitely on caffeinated drinks. So it's not a one rule for— I tend to move now to decaf teas, like herbal teas and things like that when I want a hot drink in the afternoon or something. And that can be a nice— you know, way to, to stay hydrated. I think if you— the other things are, if you're an athlete, if you're training heavy, if you're training either a big session in the day or two sessions in the day, then having some electrolytes in your drinks immediately before or after, or even both, to bookend those sessions is quite a good idea because that facilitates a bit more absorption. And I, I mean, I went for a run. One of the guys that works with us at PH, James, is a really decent runner, um, and he took me out for a good crashing the other day at lunchtime. You know, the first thing I did when I came back to get— before I get into it, I could tell I was getting dehydrated. I had a bottle of strong 1500 electrolyte drink because that, that way I know I'm going to absorb a lot more of that and not, not end up just peeing it out. I can rehydrate a lot faster. And, and so I think not just thinking of exercise hydration is what you drink during a session, but either end of it is important. Then the last one would probably be don't get too caught up about the color of your pee as a lot of people do because they end up chasing the fact that, "Oh, my pee needs to be clear all the time." That can be a sign that you're well hydrated, but it can also be a sign you're just drinking way too much. In day-to-day, go with how you feel and thirst and look at the color of your pee first thing in the morning because often that's a good indicator when your body's had time to recalibrate overnight. Whether you're waking up dehydrated or not. But beyond that, when you've had a coffee, a few glasses of water, your, your body's kind of then processing fluid and it's not necessarily indicative of your, your hydration status. So that's, that's a common question we get asked and always one where I have to say to athletes, look, like, don't get too obsessed about that.

Yeah, well, what— yeah, once you start seeing Guinness type of, uh, pee color during the end of an ultra, you know, uh, you know, something might be off. But, but yeah, 100%, I totally know what you mean. Um, talk about quality of water for a minute over here, because there's a lot of— like, you're obviously here in the US, there's, there's tap water, but like, it is much different than when I grew up in Holland where everyone just drinks out of the tap. Um, then there's like, right now we're using water from an actual fridge filter, which I'm even questioning the quality of that, versus there's different water machines, different like different pH levels and all that.

Can you share your thoughts on quality of the water?

Honestly, a lot of that, as long as the water is of a drinkable quality— How do you know that though?

How do you know it's of a drinkable quality? What I mean by that is it's not going to make you ill. So if the water is like not— it's not got any either any contaminants or any bacteria that's going to actually be bad for you and make you ill. Then the hydration properties of it are going to be remarkably similar, whether it's the, the bottle from Whole Foods that's cost like $6 or whether it has come out of the tap in your kitchen. You know, I think that the things that do make a difference though is that we all love the taste of like filtered, clear, cold, chilled water. It's going to taste better and you're going to drink more because palatability of drinks is really important. So I'm a big believer in like making sure that the water you're drinking is nice and palatable, because if the water that comes out your tap is a little bit cloudy looking and it's a bit warm and it's like, you're just not going to drink the volume.

Well, yeah, that part, like when I drink tap water here or when I drink it in Holland, it tastes like normal to me, whereas I drink it here in Los Angeles and like it tastes off. Yet for years I used to drink it, but then as I started I start like looking into everything I put in my body, I start reading reports and there's contaminants of this in there, there's long-term effects of cancer-causing this, like it just scares me to drink the tap water to be honest and that's why I got more cautious about what I put in the body that way.

Yeah, I think that, I mean I can't, I'm not an expert on that and I would, in the different parts of the world, the way water gets treated and served out to homes, you know,— it's always going to be different. I don't— honestly though, I don't probably think this is as much of a difference as we've been led to believe in terms of the marketing. Bottled water in particular has got big budgets behind marketing it. But one thing— yeah, falling back to what I said before, like the appeal of drinking water that's clear and tastes great and is either filtered or whatever or chilled, it definitely makes a difference in terms of how much you consume. We've got the same as you— it sounds like you— we've got a a filter on the fridge at home and the water chilled out there tastes loads better than what comes out the tap.

Yeah, yeah, for sure. Um, one more question that, that did come up when taking a deep dive into the world of salts and hydration, because first of all, I appreciate your, your entire team sending over a bunch of different, different products with the salt intake. So there's the 500 milligrams, the 1,000, the 1,500 milligrams. I have a few different questions still about this, but can you talk a little bit more about, like, so you obviously developed, like, in no way am I getting compensated for this, but I'm purely interested in your product and learning a little bit more over here. So you have different salt levels, different sodium levels in your, in your product, right? And so So is this mainly throughout training and racing that you recommend taking this in, or is this also throughout the day as far as for the hydration in between that you have previously talked about?

Predominantly, it's at times when you're sweating a lot. Yeah. So it will be for during activity. Very occasionally, like I say, we would use some of the stronger ones to prehydrate or rehydrate. If for some reason, the 1500 that you held up there, the box, that one has a little bit of sugar in it as well in that format. I think in the US, you would know the brand name Pedialyte. We have Dioralyte. It's like a medical-level rehydration. That sort of product is a relatively similar composition to that type of thing, although we use sodium sodium citrate instead of sodium chloride, so it doesn't taste quite as, quite as strongly salty. But the idea with that one is that the salt— the more sodium you put in a drink, the more it's— it's the faster it's absorbed up to a certain point, and the more it's retained within the body, in the bloodstream. So that's why we have these different levels. And the 500 is kind of low end, that's similar to what you'd find in most sports drinks on the market. We do one at 1,000, which is which is like a double strength, and then the 1500, which is super strong. It tends to be that the 1000 and 1500 are the ones that people gravitate towards if they're doing really long events, really hot events, when the ratio of electrolytes in a normal sports drink just isn't enough. They're not really what you would term a day-to-day drink. If you're not sweating, you're going to meet your sodium needs in your day-to-day diet and drinking water. Along with your meals is going to be sufficient to, to rehydrate. For us, it's that, that sort of exactly the people that you are probably watching this or listening to this, and that, that niche of the population who actively go out there and sweat all day. Because outside of sport, we work quite a lot with the military, with occupational health environments, where we, we have people in Texas in the US who fit insulation into roofs and houses, and it's like 120 Fahrenheit in there, like 90% humidity, and they guzzle down the 1500 stuff when they're in there because they're, they're sweating more than you or I are when we go and do a 10-mile run.

Yeah, I can't even imagine. It's them and also the firefighters that I've seen here in the last few months, even in, in California. Like, I can't even imagine how much these guys are sweating all day long.

Anti-fire department has one of our sweat testing machines and they use it with their staff to educate them on the different levels and like test if they need to give more salt and more supplements to people out in the field.

Yeah, so when you want to take this into a race environment, probably a salt, salt tap might be easier when you're actually running a marathon, I would assume. What, what is the salt, um, what, what is the amount of salt in one salt pill?

Do you happen to— it varies massively between brands, so it's always good to read the small print. The ones that we make have 250 milligrams of sodium per capsule. So yeah, that's those ones. Yeah. So the idea with that is you then take 1, 2, 3, however many it is per hour to meet your needs. If you look on the market, you'll find electrolyte capsules with as little as 20 milligrams of sodium, which are crazy low, and you might find 1 or 2 which have got 280, 300 milligrams per capsule, but the majority will be between sort of like 50 and 150, I would say. But it's, it's crucial that you read the thing because one of the first— as an athlete, I remember taking electrolyte capsules when I was racing, but I, I treated them like a lot of people still do, I think, like some kind of pixie dust where you just need a little, you just need a little bit and you don't— it's the magic is that it's there, not, not— but the magic is in the quantity that you take. It's like getting the right dose.

So, so always, as they say, always read the label. That's a really good call. One time I didn't read the label and I was popping some salt pills like candy and it had caffeine in it and I've never been awake that— like, I was awake for so long after that one too during one of my longer runs. Yeah. So, so you can always— like, there's some thought processes too about salt being bad for you or salt not being, being Good, like obviously if you overdo it, but some people truly try to avoid all salts on all of their foods and all that. Can you talk a bit more about that thought process and why you do feel salt supplementation obviously is something that is in need?

I think it's as simple as like taking what you need, you know, or getting the benefit. It's the dose makes the poison is the famous saying, and actually, you know, just thinking about it as we're talking about it in the context of running. People, people can run, people have run 200 miles a week, 250 miles a week, you know. And when you run no miles a week, you get very little, where you get zero training return on that. And as you go up the distance, you know, if you run 10 miles a week, 20, 30, for quite often at first you get this kind of linear improvement, don't you, until you reach a certain point, and then improvement tapers off. And with, with sodium consumption, it's got such a bad rap because the average person, particularly in the States or anywhere where there's a predominantly Western processed food diet, we get quite a lot of sodium in our day-to-day diet. So if you're not sweating a lot, you're probably meeting your sodium needs really adequately without even trying. When you get into sport though, when you start training multiple hours a day, if you've got a big sweat rate, if you lose a lot of salt, it can only be a few hours of training that can send you in the other direction. That's what makes it all a bit controversial because you can have a group standing there shouting, "Reduce sodium, reduce sodium," and that's applicable to a large part of the population. You can then have a group saying, "Sodium is great, take more," which is, in this context, might be us with athletes, but it's dependent on your needs. Exactly the same as it is for calories. Someone who's running 100 miles a week is going to need a lot more carbohydrate in their diet than someone whose main hobby is PlayStation.

You know, it's just spot on. It's so, so well explained right there. Absolutely. I do have two more important questions, but before I dive in, where can people find out more about you and about Precision Hydration?

Well, go to precisionhydration.com. We've got lots of resources on there. If you're interested, if you've got questions, email us at hello@precisionhydration.com. And at the moment, you can also book we've got a really fantastic team here, sports scientists, athletes that want to talk to, to you, and that you can book a Zoom call or a Google Meet call with us totally free. You just go to the website, there's a little icon to book those in, or you can go to the blog and search. And we're on all the usual social channels, we're usually @PrecisionHydration. The only one we're not actually is on Twitter where we're @TheSweatExperts.

There you go, and I will make sure to link to that in the show notes as well. 2, 2 last questions here. So obviously you have, you have gained a lot of knowledge in the field. At this point, you're truly a hydration expert. Um, what are some of the things that, like, looking now back at what you know that you didn't know earlier as an athlete that you wish you absolutely would have known?

I think one of the biggest, one of the biggest things is really appreciating the range of difference that there is between individuals. Because I got very focused on reading about what was the average or what was normal and trying to apply that to my own situation. And I happen to be an outlier, so I happen to be someone who's on the higher level. So really understanding that although there's, there is plenty of general rules when it comes to hydration, there are also some specifics where if you're doing stuff which is longer, if you're doing stuff which is hotter, you need to understand your physiology. In order to get things really right for you and invest, invest the time in that investigation to get the best out of yourself would be one of the big takeaways for me.

Spot on. And then there's a lot of different athletes here looking to become a stronger, healthier, happier athlete. Do you have any closing thoughts over here?

Any other suggestions or recommendations you would like to share? I think the biggest one for me is, as an endurance athlete, I've mentioned earlier, it's those 4 points. It's like, if you want to perform well pacing as an athlete, if I could go back to myself as a young athlete and teach myself one lesson quickly, it would be how to pace events. Because if you can do that, then you know that that's gonna be like 80% of the screw-ups. Absolutely, same here. Yeah, we've all— we're all— we still all learn that lesson numerous times. And then it's really understand what we call the 3 levers. Understand your calorific requirements, your carbohydrate requirements per hour when you're racing, your fluid requirements, and if— and your electrolyte requirements roughly. And just pay attention to those 4 things. So get your pacing right rather than worrying too much. And even I, you know, everyone does this, but you worry a lot in the build-up to race. What shoes am I going to need for this because the terrain, or because now we got on the road, we've got the Vaporfly things, and I've— do I need the latest one of those? And, and it's that gets— we spend loads of time worrying about all that peripheral stuff, whereas if you get your pacing right, your calories, your fluids, your salts, you will have a great race. And at the end of the day, that's what most of us are out for. We want We want the buzz. And don't get sucked into— we all enjoy getting involved with the new shoes and the packs and the jackets and all that, but try to stay focused on the bits that matter first, I would say.

So well said, Andy. Thank you so much for sharing all of your insights over here. Um, yeah, I will make sure to link to all of this and wish you all the best with your Precision Hydration company. Great.

Yeah, great chatting with you, Flo. And we'll have to set you up with a sweat test soon. We've got a great person just down the road from you in California where we can send you off for a sweat test.

Absolutely. I would love to do that and I'll make sure to share that on, on the YouTube channel as well then. So great. Thanks, Andy. Later. Bye. Floris Gierman with a few closing thoughts. First of all, thank you so much for listening. I know that there are many different podcasts and YouTube videos out there and I truly appreciate you tuning into the Extra Mile Show today. That really means a lot to me. Also, if you would like to find out more about our running training programs, check out 5ktohalfmarathon.com or marathonprprogram.com. Both of these programs provide additional support and additional tools for athletes who are looking for guidance in their training and in their racing. We do set up occasional Zoom calls as well where both myself and other members from the community are all learning from each other, and we're taking a deep dive into specific questions from members in the training programs as well. More info at extramilest.com/training about both of those programs. Also, Andy was kind enough to set up a 15% discount code for Extramilest Show listeners with the code Extramilest, and this can be used at precisionhydration.com. And I can also highly recommend checking out their sweat rate test and some of the other articles, deep dives onto hydration. Thanks so much for making it all the way to the end, and I will see you on the next podcast. Have a good one. Bye now.