The human body physically, mentally, and emotionally can only take so much. God has blessed us with the Sabbath how do you interpret that?
Based on a personal experience and Genesis 2:2-3: "By the seventh day God had finished the work He had been doing; so on the seventh day He rested from all his work. And God blessed the seventh day and made it holy, because on it He rested from all the work of creating that He had done."