Are your major muscles paralyzed during REM sleep?

Yes, during REM (rapid eye movement) sleep, major muscle groups are effectively paralyzed due to a mechanism called atonia, which prevents the body from acting out dreams. This paralysis is a protective feature that helps maintain safety during vivid dreaming. However, some small muscles, such as those controlling eye movement and breathing, remain active. This atonia is a critical aspect of the sleep cycle, allowing for restorative sleep without physical movement.