Recent studies have however shown that this might not be the case, with some adults needing as little as four hours sleep to wake up feeling refreshed.

Research from experts in Washington, US, found that having too much sleep could actually interfere with your cognitive function.

The experts found that people who slept less than 4.5 hours a night, and those who slept more than 6.5 hours each night had a greater risk of cognitive decline over time.

It’s key to note that all of these participants also struggled with poor quality sleep. //

the findings of the Washington study are surprising, as most health bodies, including the NHS in the UK and the Centre for Disease Control (CDC) in the US, all state that people should be having more than six hours each night.

“The study showed that sleeping longer than 6.5 hours was associated with cognitive decline over time – this is low when we consider that older adults are recommended to get between seven and eight hours of sleep every night.

“It could be the case that it isn’t necessarily the length of the sleep that matters, but the quality of that sleep when it comes to risk of developing dementia”, he said.

He did however state that it’s key to remember that the 100 participants in the study who slept for longer may have been suffering with issues that were not picked up on the tests.