Entrepreneur and New York Times best-selling author Grant Cardone puts in a lot of hours.
"There are 168 hours in a week. You should be working most of them," the self-made millionaire tells CNBC. "If you want to change your condition, you have to work. If you can outwork the rest of the population, you're going to get lucky."
Cardone, who was deep in debt and stuck in a job he hated before building his multi-million dollar fortune, logs at least 95 hours a week. The secret to preventing burnout has nothing to do with taking vacation or a personal day, he says: "Any time you're feeling burned out — any time you're exhausted — look for your purpose.
"People burn out for one reason: Because they're off purpose."