13 If you are pleased with me, teach me your ways so I may know you and continue to find favor with you. Remember that this nation is your people."
14 The LORD replied, "My Presence will go with you, and I will give you rest."
I find it interesting because Moses is wanting to learn His ways and continue to find FAVOR with the LORD. That FAVOR, I'm pretty sure, is the same thing as GRACE. So for Moses to know God and experience His grace, God is going to go with him and give him REST.
Now I do think we should do things like eat right, exercise, and have a regular sleep pattern but whether we do or not we should focus on Gods grace. When we are tired we should rely on God's grace. When we are well rested we should thank God for His grace.