Staying hydrated and energised is vital for performance, enjoyment and safety when you’re training and competing. Here’s some great advice on what you need to think about to make sure you get your hydration right.


Why is hydration important?

Despite all that has been written about hydration, it is surprising how many athletes miss this step.  Becoming dehydrated will reduce performance during training and can leave you with sore muscles and headaches – not a great inducement to get up and train again!

Fatigue hitting during your event can impact enormously not only on your finishing time but on your overall enjoyment. Hydration is crucial in staving off fatigue and helping you to get to the finish line in good time and in good shape. Becoming even 2-3% dehydrated will reduce your race performance significantly and will impact on brain function.

How much hydration do I need?

It is not just a case of drinking the odd glass of water. The average adult needs about 2 litres of water per day for general health. Other liquids such as a small glass of fruit juice (150ml) or milk will also count. But when you’re training and competing, you need more liquid on board, as your body uses sweat to cool you down.  

You’ll need to plan your hydration, just as much as your food and your physical training.  The way that you decide to manage your own hydration during training and competing will vary from person to person, but it is vital that you understand the dangers and signs of dehydration, as well as over-hydration (hyponatremia).

Hydration for training

Planning your hydration should start well before race day – you’ll need to build hydration routines into your normal training days as well as your rest days. A good rough guide is 500ml for every 1 hour of training. It’s also a good idea to hydrate about 30 minutes before you head out with about 500ml of water.

You’ll also need to rehydrate when you finish training. If you want to get really technical about how much water you need after training, you can weigh yourself before you run and then again when you get back. You need to drink one and a half  to two times the weight you lost - so if you lost 1kg in weight, you need to drink 1.5-2 litres of water.

Hydration on event day

For short events – less than 45 minutes – you probably don’t need extra water on board, but for events of more than an hour you will need to top up as you go. Having a race plan for what to drink and at what point can help you stay on target. Practise your hydration plan at least twice during training so you know what works for you, so you know you are getting the fluids you need, and you can focus on getting to the finish line.

On event day, make sure you hydrate in the hours coming up to the event. It is good to get around 500ml of water in the hour or two before you start. But make sure not to over hydrate – you will end up needing toilet stops way too often! Again, practising during training will help you get to know what works for you.

Rehydration and recovery

Rehydration is a key part of your post-event recovery. Aim to drink 1 litre in the hour after you finish.   A good sports drink will give you much needed water as well as help to rebalance your electrolytes and start to refuel your muscles. Keep sipping water and other isotonic drinks throughout the rest of the day.

A good way to check your hydration is the “pee test”.  Quite simply, when you pee, it should be light-coloured to clear. If it is dark, then you need to drink more water. (You may find it is darker first thing in the morning, but it should never be that dark again for the rest of the day).

Try to stay away from alcohol as it dehydrates you and can slow your recovery. Many sports people have the motto “no beer ‘til it’s clear” after an event – use the ‘pee test’ again to make sure you are well-hydrated before you have that celebratory drink!

Alternatives to water

Not everyone likes plain water, although you can learn to like it! You can add something to flavour it, just be careful that you look after your teeth. Choose sugar free cordials and keep an eye on sugary drinks. You can flavour water with fresh mint leaves or cucumber, and herbal teas are a good option when you have finished training, However, it is worth getting used to some plain water as well as this has the least impact on teeth and a great impact on hydration.

A large amount of research has gone into understanding the best ways to keep hydrated and there are more and more products available to help runners with their performance. These include:

Dissolvable tablets: These little tablets quickly dissolve in tap water to give you a much needed boost of electrolytes. Practically free from calories but packed with the salts and minerals you lose whilst exercising, they can be used before, during or after exercise. They are also small enough to be carried on longer races and added to water at designated stations.

Powder: Powders come in many forms - some hydrate, some energise, some even aid recovery while you sleep. There are different formulations - a carbohydrate drink before a run can provide energy, whilst a protein based drink can aid recovery - but make sure that you select the right one; some muscle building alternatives can stimulate weight gain and hinder your running!

Energy gels & chews: Gels and chews are not designed to replace water, they are a super concentrated, liquid food. They are usually carbohydrate based with added stimulants such as caffeine. Nearly all need washing down with a good mouthful of water. You’ll need to regulate your intake carefully to avoid peaking and crashing, and make sure to hydrate as well.​

Sarah Keogh | Consultant Nutritionist - MSc., BSc., MINDI |