Fast Company asked 15 CEOs to talk about their nightly routines.

One thing CEOs love to talk about is how much sleep they get. Some are vigilant about their sleeping hours. “I will usually sleep eight hours a night,” Warren Buffet has said. “I have no desire to get to work at four in the morning.” For others, sleep is more of an afterthought: Indra Nooyi reportedly slept no more than four hours a night while running PepsiCo. And last year, Elon Musk told the New York Times that he was working 120-hour weeks to meet Tesla production targets. “There were times when I didn’t leave the factory for three or four days—days when I didn’t go outside,” he said.

JAMES PARK, CEO OF FITNESS STARTUP FITBIT
“While I don’t get as much sleep as I’d like, it’s still a priority for me and something I always have to work at,” says Park, who heads to bed around 1 a.m. and typically gets about six hours of sleep a night. One thing that helps Park sleep well is exercise. “I’ve found that getting exercise helps me get the best night of rest and feel most energetic, so I try to stick to a consistent schedule of at least 20-30 minutes of exercise each day,” he says.

KATHRIN HAMM, CEO OF BEDDING STARTUP BEARABY
Hamm aims for eight hours of sleep but usually manages only seven, with a bedtime of 11 p.m. She uses naps to give her an extra boost in the afternoon. “I make sleep a priority—after all, running a business is not a sprint but a marathon,” she says. “Naps have become my secret weapon. I try to divide my day in two shifts, where I get a 30-minute nap around 5 p.m., before I work a couple of hours more in the evening.”

Get the full story at fastcompany.com.