It's common knowledge that we need eight glasses of water a day to function effectively.

Except, says Dr Chris van Tulleken, this isn't true.

In the news today, he cites a study where three dehydrated athletes were given either (intravenously) no hydration, full hydration, or enough fluid to raise overall hydration by 1%.

The study found no subsequent performance difference between those that received no fluids and those that were fully hydrated. The study is part of a growing movement encouraging athletes to 'drink to thirst' in order to avoid the dangers of over-hydration, which can be fatal.

For the average individual, rather than the elite athlete, what does this mean?

Well, we can let go of the misguided fear of brains shrivelling, concentration nosediving and productivity dying from minor dehydration, which – according to Dr Tulleken – has been driven by the vitamin water and sports supplement industry with catalogues of isotonic drinks to promote.

He adds that our bodies are perfectly primed to let us know when we need to drink and when we don't need to. Drinking more than your body needs is ultimately pointless. Dr Tulleken suggests that we need to consume a Goldilocks amount of water – not too little and not too much.

So, your employees aren't going to become mindless, inefficient automatons if they miss their 2pm appointment with the water cooler. But let's face it – providing water and advice on hydration is not really about maintaining productivity. It's about providing the tools staff need to work with their natural rhythms and bodily needs and – ultimately – show that the organisation cares about their wellbeing instead of just their output.

And that leads to high engagement, loyalty, and a whole heap of other benefits.