“...All your actions should be directed to Heaven.” — Rabbi Yossi (Avos ).
One should intend to be healthy and strong in order that he should have a spirit capable of knowing G-d, for it is impossible to understand wisdom if one is hungry or ill, or if one of his limbs aches. If he follows this course all his life he is constantly serving G-d, even in his business activities and his marital relations, for his motive is always to achieve the wholesomeness required to serve G-d. If he sleeps in order to rest his mind and body and so will avoid illnesses that prevent him from serving G-d, his sleep is also considered a positive act of service.
Solomon wisely put it: “Know Him in all your ways”.
- Rambam (Mishneh Torah, Hilchot Dayot 3:3)