No water left and I've still got five miles to go.
Four miles done now for some water.
Do you forget to think about water before, during and after your run?
And have you ever wondered how dehydration might actually be affecting your
running performance?
I'm Rick and today with Anna, we're going to be talking all about dehydration.
What causes it, how it affects performance and how you can avoid it.
Yep. And stay tuned because we've even got a science experiment for you to
demonstrate. First off though, please do hit subscribe and tap the bell icon,
so you get notified when we upload new videos, all about running,
which we do every week.
Dehydration is something that a lot of people could be living with without
actually realizing and seeing the impact that it can have on your running.
In a study in 1998 of 3000 Americans,
it was found that 75% of them were actually chronically dehydrated without realising.
And that's because of the imbalance between their caffeine and sodium intake
compared to their fluid intake.
So before we jump into what dehydration is,
we thought we'd give you a bit of a visual representation of what it is and what
it can do.
Yep. Anna and I have prepared a little science experiment for you.
We've each got a potato, cut it in half and filled a bowl with water.
So I'm going to put my half of the potato cut side down
into some water and leave it for an hour.
And I'm going to do the same. But before I put the potato in the water,
I'm going to add two tablespoons of salt to the water.
Stay tuned to the end of the video, to see the results.
So what leads to dehydration and what effect does dehydration have on your body?
Well, when you exercise, you lose fluids in two different ways.
One through the moisture that you breathe out and two, through sweat.
Exercise makes our body temperature increase. Our bodies,
then regulate temperature through something called cutaneous vasodilation.
Now this is a process where heated blood is sent to the skin cells where heat
can more easily be released into the atmosphere.
This is also helped by the cooling effect of sweat evaporating.
So how does dehydration come into this process? Well,
if you have less fluids in your body,
it can result in your blood becoming thicker and more viscous.
This reduces the amount of blood being pumped around a body and can put an
extra strain on our cardiovascular system. Especially during exercise.
Our heart rate then increases to try and pump more blood around the body to retain a
good amount of blood flow to our muscles and vital organs during exercise.
As this is all occurring, there's less blood flow to our skin,
meaning our temperature continues to increase without being able to cool down.
And this can lead to heat stroke or potentially even more life-threatening conditions.
So hydration is key in order to stay healthy and comfortable,
while out on a run.
We're going to talk about dehydration and running performance,
but it's definitely important to also mention the possibility of over hydrating,
which can be dangerous leading to something called hyponatremia.
There's no one size fits all approach and drinking as much as you can hold is
definitely not sensible.
So how can dehydration affect our running?
We know that severe cases can cause serious health implications,
but can less serious instances of dehydration affect how well we run.
Short answer. Yes, they can.
Studies have found that even low levels of dehydration can have an effect on
your running performance.
Previous research has found that a loss of body weight of just 2%.
So that's one kilogram for somebody who weighs 50 kilograms, can
increase the rate of perceived effort. So in other words,
how hard it felt to run at the same pace.
Research also found that a 2% loss of body weight due to dehydration can reduce
performance by 10 to 20%.
The issue with this research is that it was conducted in conditions that don't
quite match real life sporting conditions.
So using saunas or diuretics to lead to dehydration rather than physical activity.
So these exact statistics may not be the case for all runners,
but what it does show is that dehydration can have a negative impact on our
running performance.
And therefore staying on top of our hydration can actually produce
better results.
So what could dehydration look like on a run? Well,
it could mean that your heart rate is a lot higher than normal for your easy
pace runs or that your perceived exertion is a lot higher than normal.
This is why it's important to monitor your training stats like heart rate and
perceived exertion. So you can spot those signs of dehydration early.
You might be thinking, well, why don't I just drink when I feel thirsty? And
previous research had suggested that exercise actually suppressed our
thirst and so at the point of feeling thirsty,
it's actually too late and you're already dehydrated. However,
more recent research has found that actually it can be an appropriate strategy
to drink, to thirst. Just bear that in mind though,
when planning ahead for runs,
because although you might not feel thirsty when you head out the door,
it might be the case that you get halfway round your route,
feel like you need a drink and you haven't taken any water or electrolytes with
you to rehydrate.
In most sporting activities,
there are two things that can affect our performance.
The first is reduction in carbohydrates and the second is a reduction in fluids.
These two factors can lead to fatigue and a reduction in performance.
So it's important to make sure that your carbohydrate and fluid levels are at an
optimum level to maximise performance.
This is where it can get a bit tricky though,
because that isn't a one size fits all answer to staying
hydrated.
The best way to stay on top of it is to make sure you're keeping hydrated
throughout the day and monitor your environment as well.
Hot and humid conditions are going to increase your body temperature so that you
sweat more leading to more fluid reduction than normal.
What you wear on a run will impact your body temperature.
And that's why a lot of sportswear will be made from a moisture wicking material.
So it takes sweat away from your body to help keep you cool on the run.
Wearing lots of layers and getting too hot whilst you're out
running, will end up in an increase in lost fluid, mostly through sweat.
You might want to think about how you rehydrate as well. As we said before,
you lose carbohydrates and fluids,
but you also lose sodium when you exercise as well.
And that's why sweat tastes so salty.
So a good way to rehydrate would be to take some electrolytes either before,
during or after your run.
And if you want more tips on electrolytes and the kinds of products that are out
there to help rehydrate you, make sure you check out our video all about it.
So it's time to take a look at our potatoes. Well,
mine's a bit soggy, but it looks pretty much how it did when I put it in there.
Mine's definitely seen better days.
Now, it's all shrivelled up and that's because the excess salt acts as a
dehydrator and draws water out of the potato.
Now we consume a lot of dehydrators in day-to-day life. Things like caffeine,
alcohol and foods high in sodium can all lead to dehydration.
This might be a bit confusing when we say that electrolyte drinks contain salts
to replace those lost from sweat.
But the important thing here is balance. In the case of the potato, too much.
So make sure when you're planning your weekly runs,
you also consider your fluid intake as well.
And if you're bad at remembering to drink water,
there are plenty of hacks out there to help you. For example,
you can get water bottles with lines that go up that tell you to drink a certain
amount by a certain time of day,
you can track your fluid intake on apps and on your smartwatch as well.
You can set reminders to buzz to remind you to drink,
and don't forget the old favourite, the wee test.
So you can look at the colour of your wee, to see how hydrated you
are. You're aiming for a pale straw colour.
Anything darker than that, you need to drink a bit more water.
Experiment with different ways to hydrate as well as what you use to hydrate.
So whether that be plain water or electrolyte drinks and sports supplements,
and if you think you might be dehydrated,
these are the symptoms that you need to be looking out for. So, feeling thirsty,
dark yellow, and strong smelling pee,
feeling dizzy or lightheaded, feeling tired,
a dry mouth, lips and eyes and peeing,
little, so fewer than four times a day.
So hopefully that's answered all of your questions about dehydration,
got any other tips or any other questions, leave them in the comments below,
and we will get back to you and we'll see you next time on The Running Channel.