Want some water for thought? On this episode of 32Gi Sports Nutrition, Mark Wolff shares how to handle water absorption when training and racing. This includes signs to read, ideas for helping you to absorb water better, stay at an optimal hydration level, and reduce the chances of fatigue.
Water. Water is of course the source of life, and something athletes and anyone who goes out and exercises knows all about, very important in replenishing. Mark Wolff joins myself, Mr Active, David Katz now on the 32Gi Sports Nutrition podcast. Mark, water, how much really is enough? We look at hydration quite often, but what is so key, how much does someone need in terms of a daily basis, especially people who are exercising?
Mark Wolff: David, I usually recommend 30-40ml per kg of body weight. If you’re looking at a 60kg individual, I would say anywhere from 1.8-2.4 litres of water per day is more than sufficient.
DK: Obviously our whole system uses water, we excrete water, we sweat out water, so you need to be replacing it all the time. This tends to happen more when we do exercise. How do people need to make that adjustment, or understand how they then need to increase their water intake?
How exercise impacts your water requirements
MW: Obviously during exercise there’s a lot of factors that need to come into play. That’s the time of exercise, the temperature, weather conditions, all of that will determine how much fluid you’re actually losing, and how much fluid you should be taking in.
Based on that there’s a couple of things that a person can do. Early on when I started my endurance journey I used to experiment quite a bit with weighing myself before and after a session, obviously a fasted session. I could actually measure an amount of fluid that was lost during that session under various conditions.
I got more in tune with my body and understanding basically what I needed to get away with. The truth of the matter is that the body has got an amazing mechanism called thirst, and that trigger mechanism is God given and natural. If you listen to it, you can’t really go wrong.
I don’t believe in pre-empting thirst during exercise, I believe in just drink to thirst. Don’t wait, when you feel it, just drink a little bit. If you sip frequently here and there, you’ll be fine. You can never replace the exact amount of fluid lost during exercise. You’ll always finish an exercise session or a racing session slightly dehydrated, and that’s where the recovery process comes in where you need to rehydrate.
Of course, you don’t want to become excessively dehydrated, but there’s a fine line between underdoing it and overdoing it. What I see mostly during exercise is people over hydrate, as opposed to under hydrate. I think I mentioned this a couple of weeks ago on a podcast with you. I actually also wrote it in a blog, is one morning I was going on a 100km ride, which could be anywhere around 3.5 hours or so, and I rode out of my house and down the road and I realised that I had left my water bottle at home.
I was too lazy to go back and fetch it and I just rode the 100km with nothing, and I was absolutely fine. It wasn’t an excessively hot day. It was warm, but there was a cool wind blowing so it was okay. Obviously when I finished I was slightly dehydrated, but not to the extent that there was a lack of being able to perform during my exercise session.
I think people are very afraid of that dehydrated process and yes, water or fluid intake is extremely crucial, but I would say don’t overdo it. Try and find that optimal amount that’s required to be able to sustain you during the day and through an exercise session.
The importance of the rehydration process
DK: Over hydration of course even more dangerous than dehydration. Mark looking at, say you go on a run, you talked about weighing yourself, if you lost 2kg during that run, it’s not like all of a sudden afterwards you drink two litres of water to make up for it. That recovery process has to happen over time, and you don’t want to flood the system straight away afterwards.
MW: If you think about it, there’s something called osmolality which how the fluid gets absorbed through the gut. It’s impossible for you to drink a litre of water in a minute and expect that litre of water to be absorbed, it’s just not going to happen.
Water absorption happens over a particular amount of time. If you’re looking at osmolality, you’re looking at the pressure level between what’s happening in the gut, and then the blood volume on the outside. There has to be some sort of, that’s where we get the isotonic, hypertonic and hypotonic drinks, determining how quickly, how rapidly fluid does get absorbed into the system.
In cases where you are completely dehydrated, you’ll probably have to look at more of a hypotonic drink where you’re able to pull the fluid in a lot quicker, and then not have to worry about energy replenishment. I think it’s, just a matter of understanding the absorption rate of the different fluids and understanding that each type of fluid will have a different rate of absorption.
Water on its own does not absorb as quickly as water with a little bit of sugar and salt in, as an example. That would obviously absorb at a much higher rate. The thing is, you need to try and understand to what level of hydration is actually required, and match that fluid intake to those particular requirements.
Agreed, you cannot overload your system and expect all that fluid to be absorbed at once, it’s just not going to happen. It does absorb over time and that’s the problem. During exercise we call that the ‘washing machine effect.’
If you overdo it and you’re running, you can hear that sloshing around as your body bounces up and down, you can feel and hear the sloshing effect in your stomach which means that you’ve taken in too much fluid. It’s not being absorbed and it’s just sitting in the gut. At that point you need to stop drinking, probably take in a bit of salt, maybe eat something to try and increase that fluid absorption. Then carry on once that side-effect of sloshing has disappeared.
How 32Gi Hydrate can aid water absorption
DK: Terrible place to be in. I think all runners have experienced that at some point, it’s not a place you want to be. You talked about things that help pull water through the system, and I know the 32Gi Hydrate is fantastic for doing that as well. Then it also has that added benefit you talked about, getting the salt in and zero calories of course, but it’s got that little bit of a sweet taste to it. It’s a nice break, yes, being in a fasted state and training on water is good, but there is always that need to replace minerals.
MW: I agree with you and I mentioned the story to you earlier, a couple of weeks ago I went on a 28km run, I do those sessions fasted. I have a cup of green tea or black TrueStart coffee, and then I go out. I ran my 28km, I came home, it was extremely hot, I went out very late, probably 8:30 in the morning I went out, so I definitely caught some heat towards the middle of the day. I had lost a lot of fluid and probably a lot of minerals as well.
You actually lose more fluid than salt, but over time you’re going to lose both and in significant amounts, especially when it gets very hot. I felt terrible afterwards and drinking water on its own didn’t help me much to become rehydrated, in fact it did nothing. Only within 45 minutes later did I realise I needed to actually take a hydration solution.
I took a 32Gi Hydrate tablet, I popped it into a glass and after I drank it I felt so much better. Now I’ve been doing a lot of experimenting. There’s a new thing in sports nutrition which I mentioned, which is the hydrating pre-exercise.
But if you’re using a hydration drink to do that, to help pull the fluid into the system and get those minerals in there, and this weekend I tested taking 32Gi Hydrate after my black coffee, I decided, let me take the Hydrate before I go out on my run.
This weekend I ran a 32km and again, it was in the heat of the day, I went out quite late but I pre hydrated with a proper hydration product. I just popped a tablet into the glass again, I drank it and I went out on my run. I ran 32km completely fasted, no water at all en route.
I got home feeling absolutely amazing, after running for 2.5 hours on nothing. I basically then decided, okay, at this stage obviously I’m still slightly dehydrated, way less than I was when I ran a slightly shorter distance two weeks before, but I took Hydrate again and I again felt, I just felt amazing.
It was just a completely different story, which shows you how fine-tuned the human body is and that if you can find that particular balance of energy and hydration, you can turn a session into an amazing training session or racing session, if you get that nutrition right. In that case I think I nailed it spot on. I’m quite a big fan now of mineral loading before a session, and I’m going to carry on doing a lot more research, but it seems to be on the upward trend at the moment.
DK: Plenty of water for thought there, thanks Mark Wolff for joining us once again on the 32Gi Sports Nutrition podcast.