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Andy Blow | Precision Fuel and Hydration
180 Plays8 days ago
In this episode Michelle and Andy do a deep dive into hydration for endurance running and chatted about:
- common mistakes runners make with their hydration
- hyponatremia (or the dangers of over-hydrating)
- recognising the signs of dehydration
- do you need a race hydration strategy?
- are you a salty sweater?
- electrolytes
- pre- and post-race hydration
Instagram: https://www.instagram.com/precisionfandh/
Info on hyponatremia: https://www.precisionhydration.com/performance-advice/hydration/what-is-hyponatremia-and-how-can-you-avoid-it/
How to measure your sweat rate: https://www.precisionhydration.com/performance-advice/hydration/how-to-measure-your-sweat-rate/
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Transcript
Introduction to Andy Blow and Hydration Focus
00:00:00
UKRunChat
Welcome to this episode of the UK Run Chat podcast. Today we're joined by guest who's not only a leading expert in hydration and fueling but someone who's also lived the highs and lows of endurance sports firsthand.
00:00:12
UKRunChat
and Today we're chatting to Andy Blow who's the founder of Precision Fuel and Hydration. Hi Andy, thanks so much for joining us.
00:00:20
Andy
Yeah, thanks for the invite. Good to be chatting.
00:00:22
UKRunChat
Yeah, nice to have you back on. and Andy was on, for those who've been listening a while, Andy was talking about Euro trip last year with his team Sweat Elite. That's a good episode to catch up on if you haven't already heard
Andy's Background and Career Launch
00:00:34
UKRunChat
it.
00:00:34
UKRunChat
and But today we wanted to dive into hydration with upcoming marathons and ultra marathons. And we thought we'd break down kind of the the subject really that can often confuse people.
00:00:46
UKRunChat
and So yeah, Andy, how how did you kind of get into kind of sports science and specifically hydration.
00:00:54
Andy
I, yeah, I was studying, well, I studied sport and exercise science at university, at the University of Bath in the late 1990s. And I think prior to that, I'd got into, I'd got into studying sports science, just mainly because, and I expect this is true for loads of people who end up in their, I was just into sport, and I wanted to probably work in sport.
00:01:17
Andy
I actually wanted to be a professional athlete. And ah had a bit of a go at being a professional triathlete. But a combination of there being not a lot money in the sport and probably more pressingly me not being quite good enough to be one of the very best in the world meant that that was a bit of a ah sort of a, I was always going to do something to support that alongside it. And, and so sports science felt like an obvious thing to do. I think much to the potential annoyance of my parents who would have preferred me to do something where there was more likely to be a job at the end of it.
00:01:51
Andy
um But, you know, they did let me pursue what I wanted to do, which I'm extremely grateful for. And I was one of the few people on my sports science course ended up moving straight into a career in sports science and because I got really lucky when I was studying and was offered a work placement for a year with a Formula One team because they in the late 90s, Benetton Formula One was setting up a human performance centre and they were quite innovative in Formula One at the time for doing so.
Lessons from Formula One and Hydration Strategies
00:02:19
Andy
and they... recruited me as as as a sports science intern effectively for a year and I got on with the the people running that had a really good and successful year and was lucky enough to get offered a job to go back there after I finished my studies so unlike a lot of my peers who had to go on and do master's programs or go into other could do further training or kind of pivot in their careers I literally came out of uni and got a job in sports science which was pretty amazing so
00:02:48
UKRunChat
Yeah, that's fantastic. And what an industry to work in as well, F1. That must have been kind of eye-opening, really. Tell us a bit more about that.
00:02:54
Andy
it was It was, it was an amazing experience. I had a really fantastic boss who I'm still friends with now, um a guy called Bernie Shrewsbury, who is a very elite endurance athlete and himself, he he did triathlon and a lot of road running and ran some good marathons and things back in the day.
00:03:12
Andy
And he was really supportive of me as a coach. being an athlete alongside working. So sort of it it it really fitted. The industry was really exciting to work in and it meant that I was able to make a lot of really good connections, which have been valuable to me throughout my career.
00:03:30
Andy
And I got to work with some real top performers. And I think one of the things I've enjoyed most about all the different bits and pieces I've done in my career right up until now, really, is I quite often get to mix with some of the best in the world and see up close how they do what they do.
00:03:46
Andy
and And nowadays, I'll be able to contribute to that by teaching them sometimes things about fueling and hydration. And so, yeah, it's been it's been an interesting couple of decades sort of getting into that
00:03:59
UKRunChat
Yeah. And are the things you learn kind of in the Formula One world that you've managed to bring over into running and triathlon, like real kind of application there?
00:04:08
Andy
some of it I would say I was i was young when I was in the formula one thing and I was learning a lot of real basics honestly I made a lot of mistakes as well um
00:04:10
UKRunChat
Yeah.
00:04:16
UKRunChat
Yeah. Yeah. we We all do, don't we? Yeah.
00:04:18
Andy
One of them was probably quite related to hydration, well very related to hydration as well. And um some people that follow Formula One will probably know the name Mark Webber and Mark was an Aussie driver.
00:04:28
UKRunChat
Yeah.
00:04:29
Andy
He was actually a test driver and racing in Formula 3000 at the time, which was kind of the feeder series to Formula One when I was working with him. And he He was very, we we were talking about hydration a lot. There was a lot of emphasis on making sure we tried to get the guys in the car well hydrated. And Mark was someone who took his fitness and health really, really seriously. He was very dedicated to it. And I think...
00:04:57
Andy
myself and maybe some of the other members of the team were were pushing a message that he he really did for hot races needed to get into the car well hydrated because there wasn't much opportunity if any opportunity to drink so the idea was was you know start well hydrated and one year at at Monaco um Mark was leading the race and actually crashed the car ah because essentially he we think he'd become hypernatremic he'd drunk too much water before the rest of it it led to a bit of mental confusion which is one of the symptoms he really was feeling lousy and that was a big lesson learned for him and a big lesson learned for us in the you over hydration and then this was in the this was either in the late 90s or the early 2000s and this was when kind of
00:05:25
UKRunChat
Mm-hmm.
Founding Precision Fuel and Hydration
00:05:44
Andy
I was relatively naive to what hyponatremia was and it wasn't as commonly talked about. it was definitely happening to people, but it wasn't as commonly talked about. And I think the reason it was happening was that a lot of athletes were told, you know, drink, drink, drink.
00:05:58
Andy
Dehydration is the enemy and the way to prevent that is to drink more. And if you were... a really diligent athlete obviously drinking more would mean like really going for it you know not just i'll have an extra glass of water it's like i'll have an extra two liters of water or whatever because there was no real information to suggest that you know the a dose response kind of issue so know that was that was one lesson that
00:06:15
UKRunChat
Yeah.
00:06:26
Andy
I learned relatively early on, which has probably stuck with me, but a lot of the other stuff, a lot of the rest of stuff was kind of foundational and I suppose really, would say now, like most people in their career, I would love to go back and tell myself few of the things that I've learned along the way. I could have probably done a better job at the time, but...
00:06:45
Andy
but you do live and learn one of the biggest lessons i learned from the kind of f one thing as a whole though was that i really enjoyed working with these elite performers and i really enjoyed working in an environment where performance was put first you know there was unlike some of my colleagues who worked in less well-funded sports it was difficult to get things done in sports science human performance whereas if we came up with a good idea
00:07:11
UKRunChat
Yeah.
00:07:15
Andy
the team are often had the budget and also had the entrepreneurial spirit to get behind it. So we made training rigs to um yeah to sort of strengthen the neck. We had Polar made as a customised heart rate monitor, which at the time was quite cool. It was hardwired to the watch because you couldn't use telemetry in the car.
00:07:36
Andy
um We had the engineers make drink systems with pumps that pumped um drinks to the drivers. So so it was what what I really appreciated was the opportunity to be entrepreneurial and think you know of new ideas and see them come to life.
00:07:54
Andy
So that was really, yeah that was a really fun part of the job.
00:07:57
UKRunChat
Yeah, so that that entrepreneurial spirit, I guess, is that where kind of precision fuel and hydration kind of was born, really? When when did that happen?
00:08:05
Andy
that That sort happened in the late 2000, before 2010, around 2008, 2009.
00:08:12
UKRunChat
Yeah.
00:08:13
Andy
As an athlete, I always tended to perform way better in cool conditions than in hot conditions. I had a lot of failed races in the heat. and ah And for a long time, I just assumed that I was someone who didn't perform well in the heat.
00:08:25
Andy
Like Mark, actually, I suffered from hyponatremia a couple of times in Ironman races and was in really bad shape as a result. um ah a friend of mine who was a doctor looked at some photos and saw me at some races and I was always caked in salt when I finished and he said I think the problem here is you're losing a lot of salt you know a lot of sodium um let's get you tested so I went along to the hospital went to a cystic fibrosis unit got a sweat test which tested how much electrolyte I was losing in my sweat and sure enough um ah Dr Jutley was right
00:08:57
Andy
I was losing loads, I lose about 1,800 milligrams of sodium per liter, which is to double what the average person loses.
00:09:04
UKRunChat
Yeah, okay, wow.
00:09:05
Andy
And what was amazing was that based on that, we could readjust, you know and i I worked with the doctor to adjust how much salt I was taking in, in races, and actually reduce the amount of water, increase the amount of salt a bit,
00:09:20
Andy
And it was like night and day difference. I felt so much better. I wasn't suffering with cramps anymore or not, not to the extent that I was. I was finishing races in the heat in much better shape.
00:09:31
Andy
So that was kind of the insight that then led to. And then what I did was I bought more sweat testing machines and started using them with athletes. And that was kind of what led to precision
00:09:41
UKRunChat
Yeah. Yeah.
00:09:42
Andy
hydration really. we didn't we're We're known now, precision fuel and hydration to the average person is probably known more as a products company because that's predominantly what you see on our website and that's what we sell.
00:09:48
UKRunChat
yeah
00:09:52
Andy
But we started out as a as a sort of consultancy business and hardware sales business to educate athletes on sweat, sweat sodium loss and how to hydrate more effectively for them as an individual because the advice at the time and even to an extent nowadays,
00:10:12
Andy
is pretty generic and and it's actually a topic that needs to be addressed on an individual basis.
00:10:17
UKRunChat
Yeah, yeah, that's interesting because, I mean, just going back to kind of your triathlon experience, because you you were, you say you dabbled in it, but you did fairly well. You know you were ah you were a top 10 finisher at Ironman weren't you? Yeah.
00:10:31
UKRunChat
ah
00:10:31
Andy
Yeah, i had a few, had a few reasonable results and, you know, results that I'm still proud of now, really, you know, get, because I, mainly because, not because the results themselves mean anything to anyone else, but because what I do know is that I tried, id I put everything into it.
00:10:45
Andy
I basically trained full time and went really, really hard after ah a goal, which when I look back at that age, at that point in life, some people at that point are pursuing different goals, but I was fortunate to be able to look back and go, do you know what? I absolutely, i didn't do everything right.
00:11:01
Andy
And I could have, I could have been a better athlete if I'd have been more sensible and, had more knowledge actually, but at the same time, what I did do is I went 110% into it.
00:11:12
Andy
And that's, that's been, a that was a really valuable experience to be able to do that in a time before I was running a proper business, before I had children and that sort of thing, you know, having, feeling like I sort of like threw down hard when I could is ah is a good feeling.
00:11:28
UKRunChat
Yeah, that must be nice to just be able to give it your all and and say, right, what can I do here and let's try everything.
00:11:35
Andy
Definitely. Yeah. Yeah. So it's something which I think, you know, if yeah different people you you get to, maybe you get, you get the opportunity to do it with different things at different times of
Sweat Testing and Athlete Reactions
00:11:45
Andy
your life. But, you know, for me, like working hard and training hard and playing hard was what I definitely did in my twenties, you know, and early thirties, it was a good, it was a good period for that.
00:11:57
UKRunChat
Yeah. It must be nice to pass on that experience. So, I mean, what was the general kind of reaction from athletes that you were helping back in those early days of precision hydration then?
00:12:07
Andy
it was It was an interesting one to try and convince people that they might want to do a sweat test and and take this information. Some athletes like me were all over it because they knew they had potentially had a problem with this. And for them, it was it was it didn't even require any selling. It wasn't just an easy sell. It was like people wanted to do it.
00:12:26
Andy
For other people, they were more ambivalent to it because they didn't. perceived they had a problem or didn't understand. So part of what we did early on really was kind of trying to figure out how to communicate the potential benefits of sweat testing and understanding your hydration on an individual basis. And the people we found most receptive to that were professional sports teams
00:12:46
UKRunChat
Yeah.
00:12:46
Andy
where you'd got a sports scientist who you could talk science to about the variants that you might see in sweat sodium across their squad. And then they were quite interested to use the testing to test their entire squad. And even if the individual players weren't so interested, it might allow the team nutritionist, the team sports scientists to individualize their approach to hydration a little bit, identify the athletes that were like me that had very high sweat electrolyte losses or very high sweat losses.
00:13:13
Andy
and then educate them more, maybe provide better products, more suitable products for them. And that was really, it was the request from those people for having different strengths of electrolyte product that led to our first product range. It led to us setting up Precision Hydration as a business.
00:13:30
Andy
And that was that was our start. And we we founded the business 2011 on that basis.
Understanding Hyponatremia and Human Hydration
00:13:36
UKRunChat
Yeah, no, that's that's fantastic. and So you mentioned kind of hypernitremia there. So I just wanted to pick up on that before we get kind of deep into the hydration topic, and because people might be listening and think i've I've never heard of that. Can you just explain like in simple terms, like what it is and what happens to the body?
00:13:56
Andy
Sure. um In your body, the electrolytes in your body are dissolved into um body fluids and there's a in your blood you carry quite a lot of sodium, which is the main extracellular electrolyte.
00:14:11
Andy
So in your blood plasma, the concentration of sodium is typically held between about 135 and 145 millimoles per litre. And that is what's required to maintain proper functioning and homeostasis in your body for for a number of different things.
00:14:28
Andy
If you get hypernatremia, it's a condition where your blood sodium levels drop. So they drop below 135 millimoles per litre. And if they drop a little bit below, you might feel a bit off, but you'll probably be fine. If they drop significantly below, you get this kind of cascade of potential problems which can be catastrophic and people die from hypernatremia so you know if and and that's principally because it can lead to swelling of the brain and the way it does the the reason for that happening is as your blood becomes more dilute from
00:15:02
Andy
you know the the level of sodium is dilute, your body will push fluid from the blood plasma, from the bloodstream into its own cells to kind of lock it away to preserve that sodium level in the blood.
00:15:12
Andy
And if it pushes that into your brain cells, your brain swells up and it has nowhere to go. It pushes on the inside of your skull, which obviously causes all sorts of ah negative effects. and mental and motor control consequences and ultimately that is that they can be catastrophic and people can die from it and the the number one reason why athletes suffer from hypernatremia is because is is if they drink too much water in relation to how much they're sweating out
00:15:44
Andy
And that can be compounded, especially for people like me, by also sweating out water plus electrolytes. So if you imagine, you know, you you start off with something which is yeah normally concentrated and you you've got a tap dripping that's letting some of that out at the bottom and you're just topping it up with water, sooner or later you're going to dilute it down. And that's that's basically what happens to runners or athletes who drink too much water.
00:16:08
Andy
and also don't replace enough sodium. So it's it's it's all about getting the the balance right so that you're replacing enough fluid and enough sodium to counteract what you're losing in your sweat, but not so much that you're diluting yourself down.
00:16:23
UKRunChat
Yeah, thank you. That's been explained really simply. and So how much, and I know everybody's an individual, and but how do we know how much we need to be drinking on a daily basis? Because there there is a trend, we were just chatting before we started recording, there is a trend that we need to be getting a certain amount of litres of water nowadays. People are pushing us just to drink lots of water.
00:16:46
UKRunChat
and do we actually need much water?
00:16:46
Andy
yeah
00:16:50
UKRunChat
I guess I'm asking.
00:16:50
Andy
yeah so yeah i mean human beings generally need a lot more water than other many other mammals and principally because we sweat more so that you know dogs don't sweat they still need to drink because they lose fluid through panting and through urine and through other things but they don't sweat so um they cool down by
00:17:12
Andy
bye ah panting hot air out their mouth predominantly, which is why they really sit there panting hard on a hot day in the
Creating Personalized Hydration Plans
00:17:18
Andy
shade. you know and It's actually why And the fact that you you and I sweat is why we can outrun a dog on a hot day, but not on a cold day, because we hit we both heat up, but we lose a lot of our body heat. Sweating and evaporating water off the surface of the skin is a really effective way to cool down.
00:17:36
Andy
Whereas panting out heat is less effective. the The upside of it is, is it conserves more fluid. So fundamentally humans, yeah, we compared with other animals, we tend to need to drink a lot of water.
00:17:49
Andy
And those of us that train a lot, especially in hot conditions and sweat a lot, obviously need more than the average human because of that. But the idea that there's kind of a magic number or that just like drinking more water is a good idea is quite misguided because it's it is all about just essentially meeting whatever your individual losses are. So I've heard lots of myths about needing to drink eight glasses of water a day. And there there are definitely days when as an athlete, you may well require eight glasses of water in a day or the equivalent of but there's probably a lot of days when you don't and fortunately for most of us most of the time you know relying on thirst is a pretty good mechanism you know thirst is what keeps us alive it causes us to drink when we are thirsty and when it goes away and we start peeing we often stop drinking which is sensible um so it's when you kind of override those instincts that you can start to have problems
00:18:44
Andy
Where it's a bit different with athletes is if you are training really, really hard, if you're doing if you're a runner who's doing particularly long runs, especially on back-to-back days, especially in the summer when it's hot, then there becomes a point where actually just drinking to thirst is perhaps not enough. You might need to have ah a planned approach to replacing a greater proportion of your sweat losses because thirst will only go so far. you know if you if you left it if I left it on my...
00:19:13
Andy
Saturday morning run, which is usually about 90 minutes to only drink when I'm thirsty. i probably wouldn't drink at all. And I'd get through my run. I'm not going to die, but I won't feel as strong at the end and I won't recover as fast afterwards.
00:19:24
UKRunChat
Yeah.
00:19:25
Andy
And then if you extrapolate that out and if you're doing an ultra and you run in for four or five hours, there's no good waiting until you're two hours in and get really thirsty before you start drinking. You've got to get in front of that with a pre more of a pre-planned approach.
00:19:39
Andy
and And I think that's where there's a a dichotomy in that people will say some people are very strong proponents of like if you're an athlete or any if you're a person you just need to drink when you're thirsty and that kind of a nice soundbite and it sounds like good advice you know we've we've evolved this far we've we oh we've survived this long what you know and i often hear people say well i don't need to tell my dog when to drink or whatever and it's like yeah but your dog's not going to try and run 249 at london this year you know your dog is literally just using its instincts to stay alive you know if you want to get peak performance out yourself then i think a lot of athletes can do better than just solely drinking to thirst
00:20:22
UKRunChat
Yeah.
00:20:23
Andy
But the other, ah the option of beyond thinking to thirst isn't just to go, i'm going to drink as much as I can because we get these problems with hypernatremia and we don't, yeah it's not just a case of more is better.
00:20:37
Andy
it's It's essentially matching your hydration intake to um your output in terms of sweat and other losses. And that doesn't need to be calibrated to the milliliter or the milligram.
00:20:52
Andy
But it's useful to quantify sweat loss, sweat sodium loss, and then play around with different levels of replacement as an athlete until you find a sweet spot that kind of works for you
00:21:04
UKRunChat
Yeah, so how might we start to put together a kind of personalised hydration plan, whether that's very scientific in a lab or whether that's us kind of having a play around, where where might we start?
00:21:15
Andy
the I think the most rudimentary way of doing it, which and and I don't mean that in a derogatory way, this can be good enough for a lot of people, is to simply record how much you drink and what you drink in and around your training sessions and races and and correlate it to your performance and how you feel.
00:21:32
Andy
So you know if you're mindful about, you know if you if you currently don't drink anything on your long run at the weekend, but start drinking alcohol,
00:21:32
UKRunChat
Yeah.
00:21:41
Andy
even 250, 300 millilitres an hour in those runs of an electrolyte drink, say, and that correlates to you feeling better at the end and stronger at the end and recovering faster, then that's that's a learning. And that might be enough for you as a as a relatively casual runner. you know you might And then you might tweak that number up in the summer and it might come down in the winter. And that's kind of perhaps as far as you need to go.
00:22:06
Andy
For the more performance and scientifically minded people, doing two types of sweat tests can be useful. The first one is one you can totally do at home. You just weigh yourself before you go for a run and you weigh yourself afterwards.
00:22:19
Andy
Ideally and on a run when you don't drink anything or when you very carefully account for what you do drink. And then you look at the difference in weight. And for every kilo of body weight you lose, that's about a litre of sweat lost.
00:22:31
UKRunChat
Right.
00:22:31
Andy
and i And ideally, you do that over a number of sessions at different intensities, different durations, different environments, and you see how much what your kind of range of sweat losses are.
00:22:44
Andy
And we have a downloadable spreadsheet on our website. you go to precisionhydration.com and into the knowledge hub, there's a downloadable spreadsheet you can find, which will help you crunch those numbers. So you just have to put in your starting weight, your end weight and the duration of your run and it'll work out your sweat rate for you.
00:23:00
Andy
And that gives you an idea of like how much sweat in total you're losing. And we tend to see people losing as little as a couple of hundred millilitres of sweat per hour in colder conditions, people with lower sweat rates, right up to in our lab where we've got a heat chamber that got up to 40 degrees, we we'll see people sweating out close to three litres an hour sometimes.
00:23:20
UKRunChat
Wow, that's loads isn't it? Yeah.
00:23:21
Andy
which is a massive difference.
00:23:22
UKRunChat
Yeah.
00:23:23
Andy
The average is probably for most runners, most of the time is gonna be somewhere around a litre an hour, um give or take, but that range is considerable. So if you are, ah and and probably really useful knowledge if you are a sweatier person to get a handle on how much you're losing per hour, especially at race intensity, in race conditions, in race clothing, because that's what's gonna then help inform how much volume you might wanna drink um it doesn't mean you need to drink 100 of what you're losing what the the ratio of replacement is going to depend on the principally on the length of the event because in a shorter like in a half marathon you're probably only going to need to drink a little bit probably drinking to the dictates of thirst is fine because you're going to start well hydrated hopefully
00:23:53
UKRunChat
Right.
00:24:14
Andy
and you're go to end a bit dehydrated, but not so badly dehydrated that performance is cratered. and And you might drink a little bit in between just to help offset that. In a marathon, probably most athletes will benefit from a bit more of a structured plan and drinking a bit more aggressively. And then in an ultra that goes on for hours and hours, you might have to come close to meeting 100% of the losses through a lot of the race, because otherwise you're going to end up catastrophically dehydrated.
00:24:41
Andy
But that's where a bit of trial and error. You're not going to, what you're certainly not going to want to do is drink more than you're sweating out. And you're probably going to want to drink a little bit less is the general rule of thumb.
00:24:52
UKRunChat
Yeah, so it's good knowledge going into kind of a ah race, knowing roughly how in much you sweat out so that you can at least plan not to drink more and cause
Hydration Strategies for Races
00:25:01
UKRunChat
any issues.
00:25:01
Andy
Yeah, or or actually in ah in a marathon it's different because the availability of drinks isn't going to be a limiting factor.
00:25:01
UKRunChat
Yeah.
00:25:07
Andy
Most marathons have, you can carry drinks plus there's a lot of aid stations.
00:25:09
UKRunChat
Yeah.
00:25:11
Andy
So it's more about you having an idea of like what's a reasonable level of fluid consumption. like I'm going to run a marathon in December this year in California and my current plan probably has me drinking about half a litre an hour through that, which is probably only about half of what I'll sweat out, but it's it should be enough to replace enough so that I'm not on my knees at the end, you know, as long as I've taken some fuel in.
00:25:31
UKRunChat
Yeah.
00:25:40
Andy
But in a in a really long ultramarathon, you might actually be up against like, how much can I carry? How much do I need to carry between aid stops? What's available where? And that there can be a lot more detailed plan. Like we work with athletes that are running the Western States 100, which is a very competitive and a very hot ultramarathon in Northern California.
00:26:00
Andy
And a huge amount of, thinking goes into exactly how many flasks of fluid or any how many and bottles they're going to carry from one aid station to the next because the distance between aid stations is different.
00:26:13
Andy
That race starts effectively in the snow and finishes 35, 40 degrees heat. So you've got a whole load of variables that you need to consider and ah and a really kind of more structured planned approach to fluid availability and fluid intake is needed.
00:26:31
UKRunChat
Yeah. and I mean, what what kind of signs can we be looking out for and during a ah long race like that if we perhaps aren't rehydrating properly?
00:26:43
Andy
Often, if you're not particularly experienced, it will be like you you'll so you'll suddenly find you get thirsty. And that's one of the biggest signs. You probably stop peeing because I think during a long distance race, perhaps not during a marathon, but well, not during a marathon actually, but during a a longer race, you are going to stop to need to stop and pee occasionally.
00:27:03
Andy
And if you're not doing that at all and haven't for many hours and you're feeling thirsty and craving water, these are all very strong signs that you've you've underdone your fluid consumption.
00:27:13
UKRunChat
Yeah.
00:27:13
Andy
And i think I say that for more novice people, it often like comes on quickly because I think maybe they don't notice the early signs and symptoms or they haven't had a proactive approach to replacing it earlier on in the race. So it's more likely to happen.
00:27:28
Andy
but As you get more experience, you get used to reading the subtle signs and you also... hopefully keep a mental inventory in your head or your crew are keeping an inventory for how much you've you've drunk. But generally it'll be kind of, you know, you could be getting lightheaded, feeling thirsty and tired.
00:27:45
Andy
ah think most most of the kind of that feeling that most of us can relate to the towards the end of your long Sunday run, especially if it was a bit hotter than you expected and you didn't get a drink then.
00:27:56
Andy
You know, a lot of it is listening to your body's instincts and cravings. And if you're craving fluids, it's big sign that you've underdone it. And that next time, if you put an intervention in place, you know, where let's say you didn't, if you didn't drink anything or you drank a little bit, but then you up that to four or 500 mils an hour, that feeling should go away.
00:28:04
UKRunChat
Yeah.
00:28:15
UKRunChat
Yeah. OK, so if we if we start feeling like that, is it sufficient just to drink some water or do we need to be taking electrolytes on board with that as well?
00:28:25
Andy
If you're already dehydrated, there's a good chance that that electrolytes are going to help massively because they're going to help you absorb the fluids and hold on to them.
00:28:30
UKRunChat
yeah
00:28:32
Andy
And you're going to you can to not dilute yourself down as much as you would, you know, towards that, towards hypernatremia if you need to drink a lot. So I would say for people in ah in a semi-dehydrated state, taking something with plenty of sodium in it, and sodium is the key electrolyte that you need to replace because that's the one that,
00:28:51
Andy
balances out in your blood and it's the one you lose the most of in your sweat that's going to be advantageous if you're you know getting behind on your fluid intake
00:29:00
UKRunChat
Yeah. Okay. and So in terms of kind of can runners pre-hydrate or can they preload with electrolytes before a race? Is that something that you would recommend?
00:29:12
Andy
Definitely. And that is somewhere I think, especially if you take marathon runners as a as a case here, you know, being fully well hydrated on the start line is a massive advantage in a marathon because it really does mean that you can go further without needing to drink as much and you'll perform better because having, because more hydrated in the sense of ah ah of an athlete, being an athlete really means a larger blood volume.
00:29:39
Andy
And by putting extra electrolytes in your drink immediately before the race, you are going to boost your blood volume further because your body's not going to shift that fluid out and cause you to pee. So we always recommend using something strong like pH 1500 the night before in the morning of the race. Not a huge quantity, probably half a litre the night before and half a litre.
00:30:00
Andy
90 minutes before the race and there's plenty of scientific evidence and anecdotal evidence to suggest that some level of sodium preloading can really help and that's that's in contrast with people just drinking tons and tons of extra water which for all the reasons we've already discussed is not usually a good idea
00:30:18
UKRunChat
Yeah. Yeah. And of course, like I guess extra kind of keeping well hydrated will help us kind of our bodies hang on to that glycogen as well, won't it? If we're kind of taking on extra carbs, will that help?
00:30:30
Andy
I think, yeah, if you become dehydrated, it's but it's harder to absorb the the carbs and the calories that you're taking in.
00:30:35
UKRunChat
Yeah.
00:30:36
Andy
So there's a definite interplay there. um It's very hard to pick apart exactly what's happening when things go wrong, but often in the latter stages of a marathon, if you haven't drunk and eaten enough, or you've prioritized one over the other, then you're just going to be out of whack in some way. Because you might you might hydrate really well, but if you just don't take enough carbs in, then it'll be the it'll be hitting the wall that takes you down.
00:31:00
Andy
if you take enough carbs in but don't drink enough you perhaps won't absorb them and then you might have a similar problem so getting that balance of you know carbs fluid and electrolytes right is really the main job of your race day nutrition plan
00:31:14
UKRunChat
yeah it's Yeah, it's actually, there's there's a lot to think about, isn't there?
00:31:18
Andy
yeah although well
00:31:18
UKRunChat
We just need to get spot on.
00:31:21
Andy
There is, but but you can if you want to if you want to simplify it. you know On race day, you're going to need to take in carbs, fluid and sodium. And the ratio of those is what matters. So and anything else really, caffeine potentially, that might give a marginal gain for a lot of people, but it's not...
00:31:40
Andy
going to make the it's not going to be the big difference the big difference is is getting enough carbohydrate per hour getting enough water per hour and then if you are sweating a reasonable amount getting enough sodium for you with that water if you can just boil it down to getting those three things right then you if you do get it right that's your race nutrition plan sorted
00:32:02
UKRunChat
Yeah. So so really, it's actually we need to be starting with the basics, don't we? If we want to improve performance before we start looking at all these other things and hydration is a pretty crucial one.
00:32:15
Andy
Definitely. i And I think for it's crucial. I would say it's more crucial the longer the distances get.
Balancing Carbohydrates and Electrolytes
00:32:22
Andy
So, you know, like starting hydrated is a prerequisite for any race. If you're doing 5K, you want to start really well hydrated because you're going to perform better if you are rather than the other way around.
00:32:34
Andy
For a marathon it's critical, but looking at the data, you know there's a recent paper came out a couple of weeks ago from some researchers in Spain that looked at the fluid, sodium and carbohydrate consumption of marathon runners during the Seville marathon.
00:32:50
Andy
And they noticed actually that one of the biggest things that made that appeared to make a difference in finishing times was that the faster runners generally ate more carbohydrate. Now, whether that's cause or effect, you know, is is goingnna is obviously going to be hard to say because there was this was an observational study where they just looked at what people are doing.
00:33:05
UKRunChat
Yeah.
00:33:07
Andy
But certainly what we're seeing is that, you know, for for running marathons, getting your carbohydrate prioritised as as the the number one thing that's probably going to make a difference to your performance.
00:33:20
Andy
You know, if you're not hitting 60 to 90 grams of carbohydrate an hour and you're wanting to run a reasonably quick marathon, then you're probably under fueling would be the current advice. And that's what they saw in this study is that it tended to be the sub three hour runners that are doing 60 to 90 grams of carbs an hour.
00:33:37
Andy
And as people got slower, they were doing less, which is, you know, and arguably they shouldn't be.
00:33:41
UKRunChat
Yeah, yeah.
00:33:45
UKRunChat
No, so it's more they're just making mistakes with fueling and hydration. So yeah, sorry, just so just to digress a little bit from hydration, because you are obviously and kind of an expert in in fueling as well.
00:33:49
Andy
Yeah.
00:33:58
UKRunChat
And what what would your recommendation be for the best way to kind of fuel and hydrate on a marathon? So but Are we looking at water? we looking at a drink with electrolytes in?
00:34:08
UKRunChat
Would we be alternating them? And then we'd have gels along the way.
00:34:14
Andy
it's It's honestly really doesn't matter as long as you hit the numbers for those three things.
00:34:18
UKRunChat
Right.
00:34:20
Andy
So, you know, <unk> if we give a real ballpark and these, ah in some ways I don't like giving ballpark views, people put too much emphasis on them, but but also to make it real, you've got a kind of, you've got to start with with numbers.
00:34:20
UKRunChat
Yeah.
00:34:29
UKRunChat
Yeah.
00:34:34
Andy
And I would say, if we take a three hour marathon runner in normal, marathon running conditions, either spring or an autumn marathon in the Northern hemisphere where hopefully it's about 10 degrees Celsius or something. And so it's temperate conditions.
00:34:52
Andy
You're not going to be, you sweat a good amount, but you're not going to sweat loads. I would be saying to someone, look, if you if you were getting 75 grams of carbohydrate an hour, give or take, if you were getting about four to 600 millilitres of fluid an hour,
00:35:07
Andy
And probably about 500 to 1000 milligrams of sodium per litre of fluid. So, you know, probably that's going to be about 500 milligrams per hour at the upper end.
00:35:19
Andy
then that's a really reasonable starting point to then adjust it upwards or downwards based on your sweat rate, based on your energy expenditure and your tolerance. Now, whether you take like two or three gels an hour plus a bottle of water plus some salt tablets, or whether you have an electrolyte drink with carbs for a lot of that plus a gel, it doesn't really matter. It's down to sort of personal preference, what you prepared to carry, what's available on course.
00:35:46
Andy
For me, i think it's a simple strategy these days is to carry your own gels because then you can use as many as you like in flavors and textures that you really get on with.
00:35:52
UKRunChat
yeah
00:35:59
Andy
There's plenty of good pairs of shorts nowadays that can carry you know tons of gels. The ones with pockets on the sides and pockets around the belt, you can get 10 gels in those things if you need to without compromising your performance.
00:36:14
Andy
And then you can you can either then carry a handheld drink to get you started and then pick stuff up off the course, or you can rely on picking all of your drinks up on the course. And if you need, if you're a very salty sweater and you need extra electrolytes, you take some electrolyte capsules.
00:36:29
Andy
That's a really elegant way of doing it. You know, a lot a lot of the professional athletes we work with, they go more towards liquid carbs, but then they have their own aid stations every 5K where they can pick up their pre-mixed bottles.
00:36:39
UKRunChat
Yeah, it's heavy, I guess, to carry all that liquid, isn't it?
00:36:42
Andy
Yeah, they won't so they won't typically do it.
00:36:42
UKRunChat
Yeah.
00:36:45
Andy
Now, interestingly, based on some research that was highlighted to me not long ago, actually running with a a small bottle in your hand or even one on the waste pack actually doesn't add a huge amount of energetic cost to the running it does add a little bit of and it makes it a little bit less efficient but not massively so when you take into consideration the offset of like not having to deviate to tables and volunteers to pick up drinks and the fact that if you get dehydrated and depleted of energy you're going to slow down even more
00:37:09
UKRunChat
yeah
00:37:18
Andy
That being said, i no elite marathon runners, you you just don't, and I don't believe you'll ever see them carrying their own drinks. you know just it's It's culturally not what they want to do.
00:37:31
Andy
runners Runners, we're all the same. We get used to running in a pair of shorts and a t-shirt. We don't
00:37:36
UKRunChat
yeah
00:37:36
Andy
we don't like Carrying extra stuff you go up into the world of ultras though and there's a lot more acceptance You're running a little bit more slowly and people are very accepting of the fact that yeah i might have to wear a belt which carries soft flasks and gels and things I might carry a pack even with a camelback in it or whatever so i think that <unk> Don't worry too much about the formats of what you're getting Use whatever is most appropriate for you what you get on with and what's available
00:38:04
UKRunChat
Yeah.
00:38:06
Andy
and But get your numbers right.
00:38:08
UKRunChat
Yeah.
00:38:08
Andy
That's in the hierarchy of needs, getting your carb, fluid, sodium numbers nailed is the only job that really counts.
00:38:16
UKRunChat
Yeah, that's perfect advice. Does that change? Because we've been talking about kind of faster, more elite marathon runners. What about someone who's taking maybe four or five hours to run a marathon?
00:38:26
UKRunChat
how How might a hydration and fueling strategy change there?
00:38:31
Andy
Yeah, that will. So hydration, i would, you know, unless you're running dramatically more slowly or the weather's a lot cooler, your hydration requirements per hour are probably going to be similar, maybe even a little bit more if you're out there a bit longer.
00:38:42
UKRunChat
yeah
00:38:46
Andy
If you're working at a relatively high intensity still for you, you're going more. you're going to want to hydrate at a level that's appropriate. And the longer you're out there, the more accumulative dehydration you can build up if you don't drink enough.
00:38:57
Andy
So being mindful to make sure you're drinking enough in the first couple of hours, especially of a four or five hour marathon, is going to be important.
00:39:03
UKRunChat
yeah
00:39:05
Andy
With the carbohydrates, there's a strong argument to suggest that where the elites might be taking 90, even 100, 100 plus grams an hour that might not be beneficial or necessary if you're running a little bit more slowly but i would still say that we'd we'd be recommending 60 grams of carbohydrate an hour which is the equivalent of at least two energy gels an hour which is it does seem a lot yeah
00:39:25
UKRunChat
Yeah, but that seems a lot. I think a lot of runners listening will be thinking that's a lot because I think possibly we don't take enough fuel on board, do we? Yeah.
00:39:33
Andy
think culturally runners are behind cyclists and triathletes when it comes to acceptance of of the benefits of fueling that much.
00:39:35
UKRunChat
yeah
00:39:41
Andy
And that's because quite rightly, they'll ah identify that they can run a marathon or whatever on less. Like I know plenty of old school runners who did their best marathons on a banana and a glass of water. And some of them ran incredibly impressive times.
00:39:56
Andy
So it it is doable with enough training. But it ah just because it's doable doesn't make it optimal. and you know all of the available scientific evidence and a lot of what we're seeing suggests that taking at least 60 grams of carbs an hour you ideally in a sort of two to one glucose fructose ratio which sounds complicated but it just just means that whatever gels or drinks you use you just look a lot of them are formulated nowadays with two parts glucose to one part fructose that makes it easier for the body to absorb a higher amount carbs
00:40:26
UKRunChat
Yeah. Fructose can kind of, is a bit harder to digest, is it?
00:40:30
Andy
It just needs more processing by the body.
00:40:32
UKRunChat
Right.
00:40:33
Andy
so But but it's absorbed ultimately, it's absorbed in the gut via a different channel.
00:40:38
UKRunChat
Yeah.
00:40:38
Andy
so So essentially, it's kind of like having two lanes open in the gut rather than one. And as long as you as long as you're taking that in, you know that's that's the main priority.
00:40:51
UKRunChat
Yeah. Okay. So we've talked about electrolytes. Can too much sodium causes any issues?
00:40:58
Andy
Definitely, yeah. And that's where you if you mix drinks up to about 1500 milligrams of sodium per liter which is what we'd recommend for the saltiest heaviest sweaters then you should be okay because you are by definition you're taking that sodium in with a reasonable amount of liquid and so you're not going to cause a major disturbance in the body you know your your blood runs at 3600 milligrams per liter of sodium so even by introducing 1500 milligrams per liter in what you drink you're not making your blood saltier
00:41:33
Andy
um when If you take salt tablets or sodium supplements or or in fact actually gels with lots and lots of sodium in them but you don't drink much water, that's when you run the risk of making dehydration and what's called hypernatremia.
00:41:49
Andy
So like hyponatremia is what most people are scared of most of the time but hypernatremia happens when you take too much salt in or you become dehydrated and take more salt without enough fluid.
00:41:50
UKRunChat
yeah
00:41:59
UKRunChat
yeah
00:42:00
Andy
then that's when you'd have a problem and usually that'll manifest itself with making you feel very very thirsty and perhaps even being sick or getting diarrhoea so i would say you know just being sensible and again not not doing the the thing which a lot of athletes do and thinking if some sodium is helpful then more will be better it's just that you you need to get an appropriate dose
00:42:09
UKRunChat
right
00:42:23
UKRunChat
Yeah. So really, it's about knowing what those numbers are to start with for you and just having a plan, isn't it?
00:42:27
Andy
yeah
00:42:29
UKRunChat
Following a plan for the weather conditions.
00:42:32
Andy
Yeah, and hopefully having practiced that plan numerous times beforehand so you you know what it feels like and you know that you're going to get it right.
00:42:39
UKRunChat
Yeah.
00:42:39
Andy
yeah We all say nothing new on race day and I'm convinced that that often Well, I've met enough athletes at pre-race event expos to know that that isn't always religiously followed.
00:42:52
Andy
you know you see You still do see people buying shoes on the Friday or Saturday before the race and you still see people buying new gels or having not tried the gels that they're going to pick up on the course, which I think is a mistake.
00:42:55
UKRunChat
yeah
00:43:03
UKRunChat
Yeah, trying the ones that they're handing out for the first time during the race.
00:43:05
Andy
Yeah.
00:43:06
UKRunChat
Yeah. Yeah, it's always worth looking up what a race offers, isn't it? And just trying them.
00:43:12
Andy
Yeah, definitely.
00:43:13
UKRunChat
and are there Are there any other specific hydration issues that you commonly see runners making? Okay.
00:43:19
Andy
think the the main ones we've we've sort of touched on, but they would be drinking too much plain water before a race and not not taking, you know, not doing the sodium preloading to prehydrate rather than just drinking loads of fluid and actually flushing their bodies out.
00:43:26
UKRunChat
Yeah.
00:43:34
UKRunChat
Yeah.
Post-Race Rehydration and Recovery
00:43:36
Andy
And the the other one, again, we've touched on it, is really either not having a plan or not starting drinking early enough in a longer race. Because if you do just leave it to instinct, you can run for really quite a long time. You could easily get 90 minutes into a marathon without feeling like you need a drink.
00:43:53
Andy
And in my view, that would be a mistake to have not started drinking much, much earlier. you know So I tend to now, when I'm doing my longer runs a weekend, take a flask or two out with me and I'll consciously start drinking after the first three or four kilometres, which is usually sort of 15, 20 minutes in.
00:44:13
UKRunChat
Yeah.
00:44:13
Andy
um It doesn't feel like I need a drink at that point. But I know that if I keep sipping away from there, then I'm likely to feel better later on. So it just becomes a learned habit.
00:44:23
UKRunChat
Yeah. What's the best way to rehydrate after a long run? Would you use electrolytes then as well?
00:44:29
Andy
Yes, definitely, because you you will be in some level of deficit.
00:44:30
UKRunChat
Yeah.
00:44:33
Andy
And so ah usually a thousand or 1500 milligrams of sodium per litre is a good concentration. And then really drinking ah yeah as much as you feel you need to to rehydrate.
00:44:45
Andy
And by putting sodium in it, you'll absorb it a lot ah lot better and you'll hold on to it a lot better. You there's ample scientific evidence where they've tested rehydration capabilities of different drinks and the ones with the high sodium quantity always come out as the best for fluid retention after exercise.
00:45:05
UKRunChat
Yeah. Yeah. it's Yeah. It's helping the body kind of to absorb it all, isn't it? and So how do you know when you're fully rehydrated then after a race, how long would that generally take?
00:45:16
Andy
really massively depends on the level of food jo you've suffered you know from a 100 miler in the heat it might take you 48 hours to regain your normal body weight if you can get a read on what your body weight was pre-event and post-event then that's if you if you really want to know i would say a more practical way though is just when you stop when you stop feeling thirsty and you start peeing normally
00:45:19
UKRunChat
Yeah.
00:45:26
UKRunChat
Yeah.
00:45:39
Andy
And I would say for most people that should be within, certainly should be within 12 to 24 hours after the event if you've not got horribly dehydrated.
00:45:48
UKRunChat
Yeah. OK. Oh, thanks, Andy. That's been really helpful. is Is there anything that we've kind of missed there that you feel we also need to know or any lasting thoughts you'd like to leave people with on hydration?
00:45:59
Andy
I think one one thing that might be valuable to people if they're just starting to plan their fueling and hydration for an upcoming race is that on our website, we have something called the free fuel and hydration planner. So you can click on there, you can answer some questions about your physiology, like how much you sweat, how fast you're gonna run,
00:46:18
Andy
the distance of the race, the likely environmental conditions, and it will spit out for you a calculation which uses an algorithm based on all of the scientific evidence we've talked about to give you ah carbs, fluid and sodium range for the race.
00:46:34
Andy
And that is is a really useful starting point. to enable you to start to figure this puzzle out for yourself. So what I'd say is if you have got race coming up, maybe consider using that free calculator, get a recommendation, try hitting those numbers in training sessions and see how you feel.
00:46:51
Andy
Because as a buts a practical step, that's a really easy way to sort of take something from this and actually apply it.
00:46:59
UKRunChat
Yeah. Oh, that's great. Thank you. Yeah, hopefully people can can go and have a look there and and maybe there might be some surprises.
00:47:06
Andy
yeah Yeah, I think for most runners it will tell you that you need to have more carbs than you're expecting would be one thing.
00:47:06
UKRunChat
Might help them improve their performance.
00:47:10
UKRunChat
Yeah.
00:47:11
Andy
Potentially a little bit more fluid as well. but And you shouldn't take it as gospel. It's a guide. you know Some people will benefit from a little bit less.
00:47:17
UKRunChat
Yeah.
00:47:19
Andy
Some people will need a bit more. But it should get you in roughly the right zone.
00:47:24
UKRunChat
Yeah. Oh, well, thank you so much for your time today. It's been really useful.
00:47:28
UKRunChat
So hopefully,
00:47:28
Andy
yeah It's been it's been yeah lovely to chat again, Michelle.
00:47:31
Andy
and that yeah thanks for Thanks for inviting me on.
00:47:33
UKRunChat
yeah, thank you. So hopefully everybody out there listening has enjoyed. If you've got any more questions, I'm sure Andy will be happy to answer them via the Precision Fueling Hydration Socials.
00:47:43
UKRunChat
and And you can also go and have a look on their their website to find some resources to help.
00:47:43
Andy
Yep.
00:47:43
Andy
yep
00:47:47
UKRunChat
But do let us know if you've made some changes to your hydration or fueling and if it's helped your performance. We'd love to hear from you. and Until the next episode,