In layman’s terms, the vagus nerve acts almost like a kind of brake to stop the body’s stress response from getting out of control – kind of cool, right?
What role does the vagus nerve play in sleep?
In a similar way to the role it plays in stress, by helping the body to relax and ‘switch off’ the stress response, the vagus nerve helps to promote relaxation which could lead to better sleep.
Indeed, according to Lederle, slow breathing exercises – which are often used to stimulate the vagus nerve (more on that below) – have been shown to improve sleep quality, probably thanks to their relaxation effect.
“By helping to slow the activity of the heart, [the vagus nerve] helps to lower levels of anxiety and so the body becomes calmer overall,” she says. “Put differently, being in an open, relaxed and ‘safe’ place can then make it possible to fall asleep.”