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How to START hydrated and why that's so important


You can't get filthy without getting sweaty. That’s why we’ve teamed up with Precision Hydration to bring you a series of articles aimed at helping you stay properly hydrated when you’re out doing what you love. PH have personalised the hydration strategies of a long list of elite athletes such as Downhill MTB World Champ Tracy Moseley and World Solo 24hr Single speed World Champ Steve Day, so you’re in good hands.

PH’s multi-strength electrolyte range fits nicely with our Athlete Performance range, they also offer products and advice aimed at optimising your performance Pre, During and Post workout.

How to START hydrated and why that's so important

Take PH’s online Sweat Test to get a free personalised hydration plan with advice on what, when and how much to drink when you’re out sweating. Plus they’ll send Muc-Off customers a free £10 voucher to use to get electrolyte supplements that match how you sweat.

Ok, so let’s dive in and let Andy Blow from PH tell us more about why it’s beneficial to thing about hydration before you’ve started sweating…

When people talk about hydration, most of the time it's about what and how much athletes should drink during exercise. This is clearly important, but your performance is also massively influenced by how hydrated you are when you start exercising in the first place.

Drinking a strong electrolyte drink to optimise your hydration status before long, hot or really hard training sessions and events can significantly improve your performance.

At Precision Hydration we call this "preloading" and the practice has been widely studied in the last 20 years or so, both with astronauts and athletes. There's strong evidence that taking in additional sodium with fluids before you start sweating is effective in promoting increased acute fluid retention and in improving endurance performance, especially in the heat.


Once you start sweating, you're usually fighting a losing battle.

Starting off properly hydrated can be extremely beneficial. When you're properly hydrated you have a larger reservoir of fluid to draw from over time than if you're dehydrated.

Starting well hydrated has other benefits too. Optimal hydration maximises your blood volume and this helps general cardiovascular function and your ability to dissipate the heat produced by your working muscles. This reduces fatigue and enables you to maintain your performance for longer.

Despite the relatively obvious benefits of starting exercise well hydrated, a recent study of over 400 amateur athletes showed that around 31% of them were turning up dehydrated! And there were strong indications that this was likely to be compromising their performance, which seems like common sense, especially if you’ve ever tried exercising when you know you're a bit ‘dry’. That study certainly backs up other work I've read on the subject.

It's certainly not uncommon to see people only really thinking about hydration once they turn up to a session rather than preparing in advance. Often this just happens because those of us who aren’t pro athletes are juggling work and social life alongside workouts and aren’t always able to take the time to think about preparing properly. That's life.

But it can also be a problem for full time athletes who are training more than once a day, or when they have a very high training load. That's because uncorrected dehydration from a previous training session can make it’s presence felt when the next session starts.

We tend to overcompensate before the big day

And this can severely impact performance. Although athletes turning up to training a bit low on fluids is relatively common, it's generally less of an issue before big events. That’s not to say that turning up to a race dehydrated never happens, of course it does.

But, because athletes tend to care about their performance in the events they’ve been training for, there's a tendency to increase your fluid intake before the big day because you place extra priority on all last minute aspects of preparation.

The irony of this extra emphasis on pre-event hydration is that quite a lot of athletes can go from slightly under-drinking to significantly over-drinking pre-event. This can lead to a different set of problems including hyponatremia. This is a condition involving low blood sodium levels caused by inadequate replacement of the sodium lost when sweating and further dilution by drinking plain water or weak sports drinks. It’s something that can be really detrimental to your performance (and your health) if it goes unchecked.

What can NASA teach athletes?

The importance of sodium to hydration and maintaining your performance was further proven by research conducted at NASA at the end of the 20th century.

NASA’s astronauts were commonly found to be suffering with low blood pressure because they were losing bodily fluids (and therefore blood volume) during their time in microgravity. One NASA paper suggested that astronauts live with as much as a 3-4% deficit in total body fluid levels during a typical mission. It was causing them to feel weak, light headed and even to black out. That's not something you want to be dealing with when you’re trying to land a rather expensive space craft!

To combat this, NASA tested lots of drinks containing different carbohydrates and electrolyte mixtures and found that the more sodium you put in a drink, the more effective the drink would be at being retained in the body and bloodstream and correcting dehydration.

So, how do you ‘preload’ effectively?

Taking in extra sodium before an event to help you start hydrated is often referred to as “preloading”. To preload properly it’s all about finding a balance between being aggressive enough to achieve extra fluid retention in your blood stream and not causing GI issues or an excessive fluid build-up making you feel bloated and sluggish.

Typical sports drinks - which generally contain around 200 to 500mg of sodium per litre - are just too dilute to make a meaningful difference to your blood volume. Drinking a traditional electrolyte drink is not much different to drinking water.

At PH we settled on a strength of 1,500mg of sodium per litre (32oz) for our preloading drinks. That’s because at that strength your drink still tastes good and is easy on your gut but it’s still very effective at boosting your blood plasma volume and getting you optimally hydrated before your start sweating.

How to preload before an event

  • DON’T just drink lots of water in the build-up to a race. You can end up diluting your body’s sodium levels before you start, increasing the risk of hyponatremia.
  • Drink a strong electrolyte drink (containing at least 1,000mg of sodium per litre) with 500ml (16oz) of water the night before your activity.
  • Drink another strong electrolyte drink with 500ml (16oz) of water about 90 minutes before you start. Try to finish it at least 45 minutes before you begin to give your body time to fully absorb what it needs and drink the electrolyte drink in place of water you’d have drank anyway to ensure you don’t overdo it. If you’re using Muc-Off’s Athlete Performance Pre products, you’ll already have adjusted your pre-workout routine to take the time to do something that’ll optimise your performance, so preloading should fit in nicely around that!

Preloading will boosting your blood plasma volume and doing this before intense exercise is a proven way to enhance your performance, especially in hot conditions. That’s because having more blood makes it easier for your cardiovascular system to meet the competing demands of cooling you down and delivering oxygen to your muscles.

Preloading may also help you get away with drinking less in shorter/harder events where normally you’d have to consume more on the move (not easy when you’re flat out!). It can also help reduce the amount of times you need to pee before you start.

Drinking a stronger electrolyte drink before you start can also help you avoid/alleviate muscle cramps, especially if you’re prone to suffering from them late on in events and especially when it’s hot.

If you’re looking for a way to optimise your performance then testing preloading is well worth a try. To get advice on what to do when you get going and start sweating, take our free online Sweat Test to get a free personalised hydration plan. We’ll send you a free £10 voucher to use to try our stronger electrolyte drinks.

Train hard,

Andy Blow has a degree in Sport and Exercise Science and was once the Team Sports Scientist for Benetton and Renault F1 teams. He founded Precision Hydration to help athletes solve their hydration issues. He also has a few top 10 Ironman and 70.3 finishes and an Xterra World Age Group title to his name.

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