Our bodies are made up of about 70% water and we need to this to function properly and survive.
If we lose some of this we need to replace it or there can be severe consequences.
Water Loss (as % of Body Weight)
1-2% Thirsty / Impaired Athletic Performance
3-5% Impatience / Nausea / Heat Exhaustion
5-10% Incapacitation / Hallucinations
10% + Circulartory Collapse / Heat Stroke / Delerium
Generally we are unlikely to lose more than 2-3% of our body weight without doing something about it, but during training
/ competition it is easy to forget and this can be a very big mistake.