The importance of correct hydration

The importance of correct hydration

Water is the most vital bit of nutrition you require. On this episode of 32Gi Sports Nutrition we tell you everything you need to know about hydration. Is there a way to improve how your body absorbs water? Why is over hydration so dangerous? Hear more…



Welcome back to 32Gi Sports Nutrition with Mark Wolff and myself Mr. Active David Katz. We recently talked about detoxing in a podcast, Mark talked about the importance of hydration. Obviously around events it’s become super important. But as bad as dehydration is you’ve got that problem of over hydration. I think everyone has had a bad experience both ways at some point in their careers.

Mark touching on that the importance of water absorption. I mean maybe just looking post-event when people are trying to hydrate, up to an event and race days. What are some of the important things? How can people or let’s just say how do we absorb water better while we are racing and preparing for a race?

Drink regularly as opposed to big gulps at once

MW: Look I think naturally you can consume water. I advise people to consume water more frequently as opposed to consuming too many large amounts at once. I mean physiologically the body, the human body is only capable of consuming a certain amount of fluid over a period of time.

That could differ from person to person. But I mean it could be anywhere from 200 and 200 millilitres per every 20 minutes up to maybe 300 millilitres per every 20 minutes depending on a person. I mean the body is only capable of absorbing a certain amount of fluid over a period of time. So obviously smaller doses of intake over a period of time will obviously help maximise that absorption.

That’s the first thing, the second thing is that obviously minerals such as salt, sodium obviously can also increase the amount of fluid that the body is capable of absorbing. The reason for that is that we look at the osmolality, in other words there’s a sort of osmosis effect that takes place in the digestive system between the fluid and obviously between those minerals. They can actually increase the osmolality in the stomach and pull the water through the tracks a lot, a lot more efficiently.

I think when it comes to events though that’s a completely different story. Because during an event there’s a lot of messages that the body receives. Sometimes it tricks the mind to thinking you need to drink more or maybe you need to dress less. Heat plays a very critical role, temperature plays a very critical role. Because obviously the hotter it is the more you craving something cold maybe to put into the mouth and you start to drink also.

How to discover your hydration requirements

So there’s a few aspects when it comes to during event. I think firstly and this is to start taking place during training. One of the things now if you really want to be pedantic, one of the things that I’ve experimented many, many years ago. I’ve actually gone and I’ve trained without any fluid whatsoever. Over a period of time in various temperatures.

I’ve actually measured my body weight before exercise and after exercise to see how much fluid I lost in the form, obviously sweat, it could be a kilo it could be two kilos. Then basically utilising that formula I could actually calculate exactly how much fluid intake I would need for an hour under various temperature conditions. To see what I need to put back into the body to try and help replenish now.

You’ll never ever, ever be able to get to the exact amount of fluids that you’ve lost. I mean if you’ve lost a kilogram or let’s say a kilogram of weight. Which is like maybe equates to a litre of fluid. If you’ve lost a litre of fluid there’s no ways that you can go and drink a litre of fluid and get that back into the body.

Your body is definitely not going to absorb it. You need to try and replenish to a certain percentage of what you’ve lost. I don’t think any athlete has really had major issues of being slightly dehydrated during an event. If you look at any of the world’s top athletes they do finish an event dehydrated.

But finishing an event over hydrated, over hydration is deadly we call that hyponatremia basically that can cause or lead to really severe issues which can even lead to death.

How do you know if you hydrated sufficiently

So I think the important thing is you need to understand during training what kind of fluid intake you require. So that you prepare your body sufficiently. So that when you racing you can try and sort of stick to that fluid intake. So that you don’t overdo it, you don’t under do it. But you know what your body can handle.

How do you know if you hydrated sufficiently? I think the most important thing during an event is that; for example I did Roth a couple of weeks ago. One of the things I feel during the bite leg, cos that’s the most important part of the entire race to be hydrated. Is that you, I feel this sort of mild feeling like I want to go to the toilet. However it not severe that it’s gonna make me stop.

Because there’s no bladder overload so there’s the slight feeling etcetera. Over a long, long endurance event that slight feeling of probably needing the toilet is fine. At that stage I know that I don’t have to take in fluid. I can actually sweat out quite a fair amount. I can start to replenish with time and try and maintain that sort of balance as I go along.

How to tell if you are over hydrated

How do you know if you’ve over hydrated during an event? It’s quite simple. I call it the washing machine effect. You basically if you running, it’s probably easier to hear, but basically you feel and you can even hear sometimes there’s a sloshing effect in your stomach. You can actually feel the water sort of bouncing up and down between the walls of the stomach.

You completely know at that stage that you’ve over hydrated. What do you need to do at that stage you need to absolutely stop drinking. There’s no reason to drink. There’s fluid sitting in your stomach and it’s not being absorbed. How do you help aid the absorption?

Well you need to take some salt to pull that fluid through the digestive tracks and get it into the system. So I think at that stage you know that’s sort of post over hydration. That’s what you’ll have to do to try and stop getting into a more dyer straight situation.

The thing is that obviously when you racing in a very hot even maybe humid environment you tend to lose a lot more fluids a lot more quicker. If you not acclimatised to that environment. And then the question is; okay I need to drink more?

Assuming you need to drink more. I think a lot of people think they need to drink more. How do you…get that fluid absorbed at a higher rate? If you are gonna drink more, by all means you need to add a mineral or even take in a little bit extra salt in order to be able to maximise the absorption of that amount of fluid that you take in. So I think I hope that makes sense. From my point of view I mean I hope that makes sense to you.

DK: It makes a lot of sense. I think you would have had a lot of people nodding their heads; one when you talked about that state in the race where you feel like you need to go, but you don’t. I think a lot of people sit there. Also with the sloshing. If anyone’s ever been there it is a terrible feeling. I mean you almost know that cannot be good for you.

What I wanna find out more is, you mentioned about salt. Using salt to help absorb that liquid. Himalayan salt now at the moment I hear so many great things about it. That could be something even if you just training on water and a bit of Himalayan salt in your water to do just that. Helps with the absorption. Is that true?

Finding the right fluid, sodium balance

MW: Look I mean whether it’s normal salt or Himalayan. Himalayan salt I think has got a few more minerals than normal salt. I haven’t gone and done an analysis. But from a health perspective it is known to have you know more mineral dense let’s say properties than normal say table salt. Same with sea salt actually.

So the thing is that I think the point of the matter is, it’s the sodium that’s quite critical in this process. It’s not really all the minerals that are involved there. It’s actually the sodium and the sodium is what’s going to help with that fluid absorption.

Why? Because, and this is something that people should know, when you sweat. Basically okay, you losing sweat is hypotonic. You basically, you losing fluid but you losing a lot more fluid than you are losing minerals. So what actually happens is that your sodium levels become concentrated okay.

As they become concentrated what actually happens is that triggers the thirst. You get that dryness in your throat. To me thirst is the most accurate trigger mechanism. It’s a God given mechanism that says here you need to drink because you have lost a lot of fluid salt. Your sodium levels are concentrated now it triggers the thirst you need to drink. You need to find that balance between fluid and sodium in the system.

Obviously if you over hydrate and you drink too much you gonna dilute you blood sodium plasma. That is very, very dangerous. That’s what causes probably swelling in the brain. It can cause failure of organs etcetera. That’s what actually leads to a dyer straight situation.

So if you in that situation you need to take salt in to be able to bring that sodium level back up and balance it out with the fluid. Dehydration is the opposite. If your fluid levels are dropping completely and your sodium levels are obviously becoming more concentrated in your system. That is not life threatening as opposed to what hypernatremia is.

I mean you know I always tell people you can wonder in a desert for three days and maybe then you will die of dehydration. But the thing is that hypernatremia is something that needs to be dealt with immediately. I think a lot of people are scared of dehydrating.

I always tell people you know if you listen to your thirst mechanism you not going to stress too much about dehydration. Because you really need to not drink for a long period of time to really get yourself into dyer straights, As far as dehydration.

Don’t be tempted to over hydrate at Comrades

Now if we look at a race at Comrades Marathon. I mean you know that there’s water tables so often on route. I mean we talking every three and a half kilometres on route there’s water tables. And what actually happens is that people tend to drink from every single table.

The point of the matter is, is that early in the morning the temperature is very cold. Obviously the temperatures build up through the day and this can be through any event. Whether it’s a Challenge event, whether it’s a long distance triathlon whatever it is.

Temperature in the morning, temperature in the afternoon is changing rapidly. We assuming it is some environments maybe gets colder. But when the temperatures do increase the problem is, is that your body doesn’t have the same rate. It doesn’t have the same rate that it did in the cooler environment.

The problem is that people start to over hydrate they start to drink a little bit more, why? Because they wanna cool themselves. Taking in the fluids on the inside makes them feel very good. That’s something they should try and avoid.

Cool yourself from the inside (actually outside rather)

Rather cool from the outside than cool from the inside. So when you talk about hydration you need to talk about what I call fluid intake management. In other words don’t overdo it. Don’t under do it. Find a nice little balance. In that case you probably wouldn’t even need to take in salt. I think salt is more for people that know they gonna take in a lot more fluids, so they need to increase the sole content.

Second of all if you look at some athletes that train in cooler environments. If you train in an environment which is a lot colder, So if let’s say somebody in the UK. They training mainly through winter etcetera. It’s a cooler environment and suddenly they gonna go and race in a very hot and humid environment.

Their body hasn’t acclimatised to that heat. So because it hasn’t acclimatised to that heat, their fluid loss is gonna be quite excessive. More excessive than somebody that has acclimatised to the heat.

Without a doubt they’ll be taking in more fluid. They would probably need to take in salt to be able to manage that fluid absorption. So there’s a lot of things to look at. But I always tell people if you train and you acclimatised to hot conditions and you gonna race in the same conditions.

It’s always a good idea to acclimatise to those conditions you gonna race in the same conditions. You should already have your hydration sort of package down pat for the actual event. Now if you training in South Africa and it’s winter and you gonna train in the European summer. You should probably go out later in the day when it’s hotter.

So maybe instead of training at 6 /7 in the morning train at 12 or midday. Don’t do those long sessions when it is hottes,t so that you can acclimatise more to those type of conditions. I know some athletes that sit on an indoor trainer or a treadmill in a room and actually switch on a heater and they heat up the room to try and simulate conditions that they are gonna race in. In order that their bodies climatise to that.

So that they can accurately, also play with their nutrition play, with their hydration strategies. Make sure that they get to the event properly prepared. In all manners so those are little tricks that people do here and there.

DK: Mark you’ve given a wealth of information. I think people are going to take a lot out of this podcast. I’m really glad you touched on that fact of over hydration. Because people still do think dehydration is the bigger risk of the two.

You talked about that salt, anyone who does endurance events knows about those salted potatoes. I’m not a big potato eater but at an endurance event there’s nothing like a salted potato. But from Mark Wolff and myself Mr Active David Katz on 32Gi Sports Nutrition. We’ll catch up with you next time.

Back to blog