Drinking is essential

Drink water to avoid fatigue, headaches and nausea.
Often those symptoms are caused by dehydration.
Don’t wait to be thirsty. Take sips of water regularly throughout the event.

Water is our fuel

Blood, which feeds our muscles with oxygen and nutrional elements, is made up mainly of water. 
When blood levels drop, our heart muscles have to work harder.
They pump more to supply the required fuel and this causes fatigue.

During Oxfam Trailwalker

Remember to drink enough while you are hiking. The loss of 1% of water = 5% of energy loss!
Rich in sugars and minerals, sports drinks are ideal for these events.
Choose isotonic drinks which facilitate the absorption of carbohydrates.
Energy gels and bars and other foods that are rich in carbohydrates can be combined with water for maximum effect.
Try to drink every 15-30 minutes. You should drink about 250 ml every 30 minutes.
Avoid alcoholic beverages, fizzy drinks and fruit juices as well as drinks that are too cold (< 10°C).
Avoid drinks that contain caffeine as they are diuretics.
After the event, rehydrate your body by drinking more water or sports drinks.