How much do I need to drink to hydrate?
To determine your own hydration needs, it is important to listen to your own body as quantities will vary, but here are some general guidelines.
Pre-run hydration
Ideally, aim to drink 400-500ml one to two hours before a run. If you’re short of time or run first thing in the morning, then try to consume 100-200ml 15 to 30 minutes before going out.
Hydrate during your runs
This will depend on how long your run is and what the weather is like. On short runs, you probably don’t need to take a drink with you, but some runners feel more comfortable having one to hand.
For longer runs you may need to take a water bottle or hydration vest with you. Aim to drink 100-200ml every 20 minutes.
One of the easiest ways is to set your watch to beep every 15 to 20 minutes to remind you to take a drink. Drinking smaller amounts at regular intervals can help you absorb fluid more effectively without a stomach upset.
How to hydrate after your run
If you want to measure how much fluid you’ve lost as sweat, you can weight yourself before and after your run to see the difference. Aim to drink around one litre of hypotonic or isotonic drink for every 1kg total weight loss. Look for a drink that contains around 50 mmol sodium per litre, as well as potassium and magnesium.
Remember that after your run you should also be looking to refuel with a good mix of carbs and protein, so a recovery smoothie can form part of your rehydration plan too.
What are electrolyte drinks?
Electrolyte drinks are fluids that contain key minerals such as sodium, potassium, magnesium and calcium and are designed to help replace what you lose through sweat during exercise. They help maintain fluid balance, support muscle function and prevent dehydration-related issues like cramps or fatigue.
These drinks come in many forms, from ready-made sports drinks to tablets, powders or DIY mixes you can add to water. Some are formulated with added carbohydrates for energy, while others focus purely on hydration with minimal sugar. The right option depends on your workout length, intensity and personal preferences.
Do I need an electrolyte drink?
For most short runs under an hour, plain water is usually enough to keep you hydrated. However, if you’re running for longer, training in hot weather, or sweating heavily, an electrolyte drink can help replace the minerals lost through sweat and support your performance.
Signs that you might benefit from one include feeling fatigued, getting muscle cramps, or noticing salt on your skin or clothes after a run.
