top of page

How to stay hydrated when training for Walking Tall Ultra


Staying hydrated is going to be crucial if you want to perform at your best during the Walking Tall Ultra.


That’s why we’ve partnered with Precision Hydration to provide you with hydration advice and electrolyte drinks that’ll help you replace what you’re losing in your sweat.


We’ll be sending you a full hydration briefing closer to the event but, for now, PH have some advice on how to nail your hydration strategy in your final months of training…


Starting training hydrated (and why that’s so important)


When people talk about hydration, most of the time it's about what and how much athletes should drink during exercise.

These are clearly important questions, but your performance is also massively influenced by how hydrated you are when you start riding in the first place.

Starting fully hydrated gives you a much bigger reserve of fluids and electrolytes to draw upon once you start sweating.


It has other benefits too. Optimal hydration maximizes 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. Learn more.


Despite the relatively obvious benefits of starting rides well hydrated, a recent study of over 400 athletes showed that around 31% of them were turning up to training sessions dehydrated!


For most short/steady training runs, just topping up with a bit of extra water in the hours before you start is all you need to do.


But, drinking a strong electrolyte drink before longer, hotter and sweatier sessions can significantly improve your performance. And it may even help you avoid cramping up late on in the workout, or in the hours after you finish, if that’s something you’re prone to.


We call this ‘preloading’ and if you want to test whether it improves your performance, follow this protocol before your next long run…


•      Drink a 16oz bottle of a stronger electrolyte drink like PH 1500 the evening before your run

•      Drink another 16oz bottle of a stronger electrolyte drink like PH 1500 about 90 minutes before you set off. Finish your drink at least 45 minutes before you start to give your body time to fully absorb what it needs and pee out any excess.

•      Drink the electrolyte supplement in water you’d have drank anyway to ensure you don’t overdo it.

•      Don't overdo your intake of plain water in the build-up to a sweaty session. You'll just end up peeing most of it out and, if you're not careful, you can even end up diluting your blood sodium levels, increasing the risk of a race-ruining (and potentially dangerous) condition called hyponatremia. Symptoms include nausea, vomiting and headaches.



Staying hydrated during training sessions


How much should you drink?

Some fluid intake is definitely required to maintain your performance when you're running for more than about 2 hours and it’s crucial when you're out there sweating for longer than around 4 hours, especially in hot/humid conditions and in the later stages of the session.

It's always tricky to nail down exactly how much you should drink because everyone’s individual needs differ - you have to experiment and learn to listen to your body to get this just right.

Every athlete is different but, as a rule of thumb, very few runners can comfortably drink much more than ~24oz per hour - especially when running hard - so unless experience tells you otherwise, it’s unlikely you’ll need to drink more than that, especially if you started well hydrated.

Feeling thirsty? Have a dry mouth? You may not be drinking enough. Try to respond to the early signs of thirst and not leave it too late.

Bloated? Fluid sloshing around in your stomach? Need to pee often during the run? You might be drinking too much. Don't force fluids down if you don’t feel you want them.

A few words on fueling and what to drink


The composition of what’s in your drink bottles will make a big difference to how well it hydrates you and how easily it’s absorbed from your gut into your bloodstream.


For long, challenging runs, a hypotonic drink (i.e. one low in carbs) is highly likely to outperform anything more calorific. That’s mainly because it’s way less likely to cause you stomach issues and sickness as the ride goes on and you satisfy your high requirement for fluids and electrolytes. Learn more.


We’d recommend largely viewing your bottles as a source of fluids for hydration rather than a source of significant calories/energy. Ideally aim to get most of your calories from solid foods, gels, bars, fruits and whatever else you’re carrying with you (or can pick up from the feed stations on the Walking Tall Ultra course). Learn more.


By taking this approach to fueling and hydration you maximize your chances of keeping optimally hydrated whilst keeping your stomach happy and getting in enough energy to see you right to the end of the run, even in the most extreme conditions.


What makes sodium so important to hydration and performance?


Your sweat is mostly made up of sodium and water (which is why it tends to taste salty and leave white marks on your running gear). It does include potassium, magnesium and calcium too, but in relatively small amounts.


When you sweat, your blood volume is gradually reduced as the sweat is drawn from your blood plasma.This increases the strain on your cardiovascular system, making it harder to pump blood to your skin (to cool you down) and to your working muscles. This obviously has a negative impact on your performance.


Other issues like a general feeling of fatigue, a loss of concentration and even muscle cramps can also be experienced if your losses are allowed to go uncorrected for long enough. Learn more about why athletes cramp up.


Up to a certain point, taking in plain water is enough to mitigate sweat losses. But, as those losses start to mount up, you need to replace the sodium you’re losing too to avoid your blood becoming too dilute (hyponatremia).


The thing is, everyone loses a different amount of sodium in their sweat, from as little as 200mg of sodium per liter of sweat, to as much as 2,000mg/l. And everyone sweats at different rates, which means that your net sodium losses over the Walking Tall Ultra could be as much as 10-15x higher than the runner next to you on the trail.



So, how much sodium should you be taking in with your fluids?


How much salt you lose in your sweat is largely genetically determined and doesn’t vary significantly for factors like diet and acclimation to a new environment. This means that, whilst you can only find it out by getting Sweat Tested, you only need to get tested once.


At Precision Hydration we have an Advanced Sweat Test, done at rest, that tells you exactly how much you lose and we combine this data with information about how you train and compete to personalize your hydration plan.


There’s a Sweat Test Center in Memphis run by the awesome guys at

BPC Performance Coaching.


They will be on site at the race offering discounted ($129 vs $175*) sweat testing and products on Friday afternoon, or you can book an advanced test with them any time by going to If you have questions for them on this, just shoot them a note to

bottom of page