Our body knows how it is moving and where it is because of a sense called proprioception, a 'sixth sense' that helps your body know where it is in the world. And it works even while you're asleep.
The most interesting part of our body that changes during sleep is our brain.
Research demonstrates a two-way relationship between sleep problems and sexual problems, as well as between satisfying sex and sound sleep. If you want better sex, you need better sleep.
Not getting enough quality sleep can have significant implications for health.