On the day of your bike ride, start with a 500ml drink when you wake up, to get your body functioning. On a hot day, aim to drink another 500ml of water an hour before you start cycling. Throughout your ride, you should follow the rule of ‘little and often’ - take regular drinks of a few sips at a time, making sure to do this before you feel thirsty, as this is a sign you are already dehydrated. After your ride, have another 500ml drink to rehydrate, and make sure to drink consistently throughout the rest of the day.