A SLEEP expert has revealed the popular sleeping position that is terrible for your spine.
The man shared, in a video on TikTok, that lying on your stomach with one leg up is the "absolute worst".
In the post, the TikTok user, who works for pillow and mattress brand Levitex, demonstrated the position that's "just a disaster".
The expert said: "You're lifting up your head. You're turning it all the way left. All the way right.
"You are fighting the natural curves of your spine, so all the vertebrae are compressing and squeezing against each other."
He added that this was damaging nerves and impacting with the blood supply.
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The man finished: "It's just a disaster. Please stop doing this."
Captioning the clip, he wrote: "The worst sleeping position award goes to stomach sleeping."
The video has been 'liked' more than 1.5 million times with over 32,000 people leaving comments.
This included many asking why it felt so good to sleep in this way if it was so bad for the body.