ENDURANCE | Marathon Training Rehydration


You’ve made the immense decision to take part in a demanding, exciting and endurance-testing event that is a marathon! Your thoughts must be bombarded with training, organising the right kit, cleaning up your nutrition – you know, the typical aspects to consider for such an event.

But what about marathon training rehydration? Is this a priority on your check list?

When training for a marathon, it is important to know that our body is made with 50-70% of water which makes up a proportion of our muscle cells and helps various organ functions – so you can only imagine how important it is to remain hydrated after losing an average 1-2 litres of water per hour of vigorous exercise (including all of those interval sessions!)


Understanding the hidden symptoms of dehydration and the astounding advantages of rehydration will allow for effective and efficient training, therefore ensuring a safer, stronger and more energised performance on the big day…

Symptoms of Dehydration

I can hear all the sighs as you read the above… It may seem incredibly obvious when you are dehydrated, but actually – some symptoms are not as easy to recognise as having a dry mouth.

Undergoing training for a marathon is a time that you need your body to function to the best of its ability – and if you’re unknowingly dehydrated, it can cause seriously poor performance.


Muscle cramps:

If you’re suffering with these, don’t assume the only reason for experience them is simply due to working too hard. It might be that there isn’t enough fluid getting to your muscles to release tension. This is often debated; however, everyone is different and there’s no harm in finding out! Drink that good old H20 and chug those isotonic drinks (see more below) – you’ll be grateful!


Possibly considered an obvious one to some. I don’t know about you, but one of the worst things to experience whilst getting on with my day is a banging migraine… this is something that I definitely notice if I’m lacking on the water front, especially after training. Losing so much water through sweat and not replacing it causes a lack of blood and oxygen reaching the brain. Ouch – avoid it.

Food/sweet cravings:

“No! Don’t do it… I can’t jeopardise my efforts” – These types of thoughts may not be your inner greed wanting to binge, so don’t beat yourself up… Under the state of dehydration, it is believed that hunger feelings are signs of dehydration as food is a natural water source for the body. In addition, sweet cravings may occur due to the brain demanding water through blood flow, in which carbs and sugar increases the blood flow to the brain(1) Replacing sugars and salts in the body with isotonic drinks should help to eliminate these cravings.

…Rehydrate before eating that cake!

Digestive issues:

Something you definitely don’t want if you’re training… if you feel uncomfortable before, during or even after training – you may find that the digestion process of your previous food intake just… didn’t happen.

Keep hydrated: flush water through the body to help avoid any acid reflux rising up from the stomach to allow for a more comfortable run!

I’m pretty sure you won’t let yourself become dehydrated now!

On the other hand, if you think you might start lacking the water consumption, read how rehydrating can benefit your marathon training…

1) Increases performance

1) It has been shown that being just 2% dehydrated can lead up to a 10% loss in performance (2) – something you don’t want to hear or even happen to you during some vigorous training sessions! Lucky we’re warning you now…

In regards to training for a marathon, this becomes an extremely important factor to pay close attention to as many of you will be performing various long interval sessions to prepare for the big day!


A dramatic dip in performance can not only have an effect on the way you perform during your training sessions but also have a detrimental effect on your confidence as training to complete a marathon really is a test of your endurance – and we all know you really want to smash it!

Let’s point out the obvious; Marathon training isn’t as simple as a gym workout. 1-2 hours training in the gym can be completed effectively without the need for extra energy fuel.

However… training for a 26-mile run isn’t exactly the same thing.

Staying on top form during your training is the absolute priority, therefore it is crucial to supplement yourself with something a little more invigorating than water.

Water will always be the go-to nutrient to cool down your body during and after exercise to efficiently replace that lost through sweat, however, it is also ver important to replace everything else lost from your body during and after intense training to ensure a dramatic increase in performance…

2) Refuels Electrolytes

Performing vigorous exercise releases an amount of sweat that causes the body to lose the likes of sodium, potassium, chloride and other key electrolytes in addition to just water – so, what does this have to do with your training?

These vital minerals not only control your nerve pulses but also support your muscles and maintain normal pressure!

To cut it short – after training you’ll be losing important sugars and salts from cells in the body that are needed to regulate your bodily fluids – which in turn, will have a big effect on your performance.


Considering that a large majority of competitors will take four hours to complete a marathon, it is clear to see the large volume of these electrolytes that would be lost!

Electrolytes can easily be replaced with a variety of isotonic based supplements for pre and post-race replenishment, preventing:

Myprotein ENER:GEL

– Muscle cramps

– Light-headedness

– Confusion

– Body and muscle fatigue

– Suddenly becoming lethargic

– Let’s not forget nausea!
Our innovative Endurance range can help support the prevention of these symptoms!

Pre and During training:

If you’re new to long distance running, you may not have come across the concept of having energy gels during physical exercise. However, they may just be your new best friend through the duration of your marathon training!

Myprotein stock incredibly convenient, pocket-sized isotonic ENER:GEL‘s containing 21g of easily digested carbohydrates, consisting of a blend of electrolytes for muscle nourishment and added B vitamins.

ENER:GEL‘s have an important role of maintaining endurance and enhancing the absorption of precious water!

Don’t worry – we’ve done our research, again and again; it’s not like eating food that decides to crop back up during exercise!Myprotein RE:CHARGE


Try anything from our Electrolyte powder with essential salts or Electrolytes Plus if you prefer tablet form – or check out our innovative RE:CHARGE post-workout Endurance formula!

For out-right convenience you may benefit from our all-in-one Recovery XS with not only an Electrolyte blend but added Vitamin C, 3g Creatine and a whopping 24g protein – We certainly don’t fault on choice!

3) Promotes Weight Loss

Marathons are often targeted by individuals as a motivational goal to lose weight – and this is great! There’s nothing more self-gratifying than aiming high and planning an event as large as a Marathon to keep you on track towards reaching your personal goals!

Although… what does weight loss have to do with the importance of rehydration? Bear with me…

I’d like to share a bit of information for those that convince themselves or others that you have to be in good shape to even think about starting marathon training…

There’s this guy named Steve Way. For those that haven’t heard of Steve, he is a British long-distance runner… a role-model to those who crave the experience, emotion and confidence of being a great athlete.

The inspiring sports-person has:

– Represented England, taking home 1st place in the 2014 Commonwealth Games – Steve earned 10th place overall

– Now the holder of the British 100km record

– Ran the London Marathon four times – all under 2 hours 20 minutes

Steve Way Marathon


Oh, and he weighed over 100kg, smoking 20 cigarettes a day…

Yes! That’s right… everyone who aims to achieve a goal has to start somewhere to complete their journey – as Steve has impressively shown!Steve Way (Before)

Steve originally set out to lose weight (Pictured right) and now he’s up there competing with top marathon runners!

Even the most inspirational, mind-blowing professional Marathon runners once started off as a beginner.

If you want it, you will achieve it – no ifs, no buts – a small amount of daily consistency will always lead you to the life you visualise for yourself in your mind. You’ve got the frame of mind – now take action and earn those endorphins!

Now that I’ve hopefully motivated you that little bit more if you did have weight loss on your mind, (I’ve mentally pumped myself up for training writing this) I can explain why weight loss is related to rehydration…

Drinking plenty of water is essential for anyone regardless of weight loss goals, however, it is extremely important that those who participate in vigorous exercise do drink more – this is due to the fact that your kidneys fail to function properly without enough water, therefore some of their duties are passed on to the liver…


The liver needs to concentrate on its primary role of metabolising stored fat into usable energy. The liver will fail to metabolise a large section of fat if it’s doing overtime for the kidneys…

whey protein or soy protein
L-Leucine for lean gains
Fat stores


Drink more water to allow the liver to burn off your fat stores!

Whilst training for a marathon, an adequate amount of water would be anything from 2 – 4 litres! Even 500ml water has shown to increase metabolic rate by 30%(2)

In addition to drinking water, it is always important to replace the electrolytes lost in your body to allow for efficient recovery. It will also allow you to be on top form for your following training sessions. 

Take home message

Training for a Marathon is something you should be incredibly proud of…

You’re putting in the dedication, hard-work, courage and applying an enormous amount of sacrifice in different areas of your life – remember how much your body will go through during these months of training.

Remember how important it is to Rehydrate…Good luck!

By Laura Bowden

Myprotein are a proud sponsor of the ASICS Greater Manchester Marathon taking place on 19th April 2015: Endurance articles will be available every week until the big day!

Tom Cornthwaite, one of Great Britain’s leading mountain runners and our very own Myprotein Ambassador has kindly provided well thought-out training plans created for all fitness levels to prepare for the experience of running a Marathon. Beginner, Intermediate or Advanced

Start now!


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