View the video below to find out why your body – and mind – needs plenty of water.

It is often recommended to have eight glasses of water per day – and a lot more if we are exercising. But exactly how much is the exact quantity needed? And how harmful could dehydration prove to be?

In the following clip, Dallas Campbell experiences a tiresome workout without taking a sip to drink. When he’s done, he has lost sufficient liquid for his blood to become more thick – bringing about his heart to pump more and more in order to compensate for it. However, that is the minimum of his worries as compared to the striking effects with his mental response times – outcomes you might need to consider when you return home from the gym.