This is the latest installment of a regular feature here at SleepBetter.org: Sleep Myth Monday, where we bust sleep myths wide open, or verify that they’re actually not myths at all.
Myth or Truth: Each night when you sleep, you grow about eight millimeters.
The reason for it is that you are in a reclining position during the night. During the day, while you’re up and walking around, the cartilage in your spinal column gets compressed, and you get shorter. While you’re sleeping, it spreads back out like a sponge due to the lack of pressure from gravity, and you gain that 8 millimeters. Unfortunately, shortly after you wake up and begin walking around, the 8 mm disappears as the cartilage re-compresses.
PS: In case you’re wondering, the man in the picture is Robert Wadlow. At 8’11” he is considered the tallest person who ever lived. You can learn more about him here: http://en.wikipedia.org/wiki/Robert_Wadlow