Rest with a running commentary attached isn't rest. An hour on the sofa spent listing everything not being done costs nearly as much as the doing would have.
The judgment is usually inherited. Somebody's father who never sat down. A house where lying on a bed in daylight meant something was wrong with you.
Worth working out whose voice it is, because it is rarely yours and it is certainly not the body's. The body is making a straightforward request in the only language available to it, and it will keep making it, louder, until something gives.