Jack Dorsey

Getty Images, Kevork Djansezian

There are only 24 hours in a day; that's something even business titans and world leaders can't change.

But you can change how you use them. Some of the most successful people in the world not only work extremely hard in the hours they have, they create more of them by forgoing sleep.

Some people are genetically wired to wake up earlier or sleep less. Others seem to thrive on less sleep only through sheer determination. For executives like PepsiCo's Indra Nooyi and Twitter's Jack Dorsey, sleep is often sacrificed in order to excel at work and still manage to have a personal life.   

To be sure, sleep deprivation — defined as getting very little sleep in one night or consistently getting less than seven to eight hours over time — comes with consequences. Fatigue can hurt performance just as much as or even more than alcohol impairment when taken to extremes. So while waking up earlier can be beneficial, be cautious about following these examples and burning the candle at both ends. 

Carolyn Cutrone contributed to an earlier version of this piece.