We all get some - but are you getting enough? Claire Concannon investigates the science of sleep and meets a pilot-turned-sleep-researcher helping the aviation industry ensure crew on long-haul flights get some shut-eye.

Sleeping isn't clever, evolutionarily speaking. We spend a third of our lives in an extremely vulnerable position, unaware of our surroundings, exposed to threats of predators. But while researchers are not fully sure exactly what the purpose of sleep is, it's clear that we need it.

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"Sleep is an absolutely fundamental biological process. It is as important to us as eating and drinking," says Professor Leigh Signal, who is on a campaign for the vital importance of sleep to be recognised. She's a professor in fatigue management and sleep health at Massy University, Wellington, with a focus on applying sleep science to workplace settings.

For her work, Leigh stays up to date with the ever-evolving and wide-ranging research related to basic sleep science. As more and more experiments are done, the importance of sleep becomes more evident. Lack of sleep impacts our mood, our emotional regulation, our immune system functioning, our metabolism and how we function on different basic tasks. When it comes to workplace settings, sleep is vitally important in terms of preventing fatigue-related accidents.

Having trained as a commercial pilot before moving into academia, Leigh is particularly suited to helping the aviation industry address the challenges many of its staff are faced with. Long work hours, changing time zones, shifting daylight hours that impact our biological clocks, and critical safety tasks that require people to be functioning well and working as a team.

Listen to the episode to learn about the basics of sleep science, what happens to us when we don't get enough, and about the planning behind the inaugural Air New Zealand Auckland to New York flight to ensure that the crew got enough sleep on the job.

To learn more:

This episode contains excerpts from The Secrets of Sleep documentary and the Eyes Wide Open episode of the Hidden Brain podcast.

There have been previous Our Changing World episodes related to sleep, including one on Sleep Apnoea, Shining a light on our biological clock, and What it takes to live a good life.

Go to this episode on rnz.co.nz for more details