How to stay fuelled and hydrated during a winter endurance challenge

By Precision Fuel and Hydration

Eating and drinking properly will be crucial if you want to perform at your best during any winter endurance challenge like Everest In The Alps, so our friends at Precision Fuel & Hydration have put together some advice to help you start and stay properly hydrated and fuelled during the event…

What hydration challenges will you face?

Whilst we often think of hydration as being more important in the summer, there are a couple of key factors that increase your fluid losses in the cold that you might not be aware of…

  1. Cold air tends to be dry (or less humid). Your body responds to this by increasing your breathing rate which, along with the decrease in humidity, increases respiratory water losses. Altitude magnifies this.
  2. You tend to pee more in both cold and high altitude environments. (When temperatures drop, your blood vessels constrict to conserve heat, resulting in the need to pee more).
  3. Your gear creates an environment where your sweat rate rises (as your core body temperature increases the barrier that stops the cold getting in, but also stops it getting out)

The bottom line is that your hydration needs are just as important in cold environments and so here are some recommendations to help you counteract these losses and keep you performing at your best throughout…

Photo by Sam Hill

What to do before each stage

  • DON’T just drink lots of water in the build up to each day. You can end up diluting your body’s sodium levels before you start, increasing the risk of hyponatremia. At best you’ll end up with a lot of fluid sloshing around in your stomach/bladder.
  • Drink a strong electrolyte drink the night before each stage to boost your blood plasma volume. 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. You’ll also have a bigger reservoir of electrolytes/ fluids to draw upon once you start sweating. Aim for drinks containing >1,000mg of sodium per litre. PH 1500 is ideal for helping you start hydrated.
  • Drink a stronger electrolyte drink (PH 1500) about 90 mins before you start each day to top-up your blood plasma volume. Finish your drink >45 minutes before you set off to give your body time to fully absorb what it needs and remove any excess.

Read more about how to start hydrated.

Photo by Sam Hill

What to eat and drink during each stage

A significant level of fluid/electrolyte intake is almost certainly going to be required to maintain your performance during each stage, even in cold conditions.

We’d recommend having electrolyte supplements in at least some of your bottles or in your bladder pack.

Everyone loses a different amount of sodium in their sweat (this is largely genetically determined) and, if you don’t get replacing that right, you risk hydration-related issues like cramp, dehydration and hyponatremia. This free Sweat Test will give you an idea of the right strength(s) for you.

Worried about cramping up? Learn more about avoiding cramp.

Photo by Sam Hill

What to drink after each stage

During a multi-stage event like this, a more proactive approach to rehydration may be needed to help your body restore equilibrium in a short space of time, which is important if you want to perform at your best the next day. We recommend drinking a 500ml bottle of PH 1500 in the hours after you finish each stage.

We’ll be providing team members with a free tube of low calorie PH 1500 effervescent tablets plus some Precision Fuel to sample, but if you want to pick up some fuel and electrolytes, use this link to get 15% off your first order.

Photo by Sam Hill

Questions? Drop an email to or book a free one-to-one video call and we’ll be happy to help you refine your strategy.

All photos by Sam Hill

Anna Rae Dowling