GK Chesterton, from 1909, waxing eloquent about the virtues of lying in bed, also has a note of caution:
I am sure that it was only because Michael Angelo was engaged in the ancient and honourable occupation of lying in bed that he ever realized how the roof of the Sistine Chapel might be made into an awful imitation of a divine drama that could only be acted in the heavens.
The caution is this: if you do lie in bed, be sure you do it without any reason or justification at all. I do not speak, of course, of the seriously sick. But if a healthy man lies in bed, let him do it without a rag of excuse; then he will get up a healthy man.