Even Jesus knew the importance of getting some rest:
Mark 6:31 (KJV) And he said unto them, Come ye yourselves apart into a desert place, and rest a while: for there were many coming and going, and they had no leisure so much as to eat.
The sabbath day is a day of rest and God said he created the sabbath for man – not man for the sabbath.
Mark 2:27 (KJV) And he said unto them, The sabbath was made for man, and not man for the sabbath.
God knows we need a day of rest.