Hydration

Event runners outside Buckingham Palace

Hydration

Dehydration means a lack of water in the body and is one of the main causes for fatigue when taking part in sports. In general, your physical and mental performance can be negatively influenced when more than 2-3% of the starting body weight is lost in fluid.

Remember to stay hydrated: before, during and after your session.

The longer the distance and the higher the temperature and humidity, the greater the need for fluids. Your individual fluid needs during an event depend on various factors, such as climate conditions, loss of sweat or running duration and intensity.
You should be aiming to consume 400-800ml in small amounts every hour that you're exercising - that's around 150ml every 15 minutes!