Aetna CEO Mark Bertolini, Jeff Bezos and other business leaders all prioritize the same habit

On Sunday, CVS announced plans to buy health insurance company Aetna for $69 billion. The proposed mega-merger will reduce healthcare costs for consumers immediately, the CEOs of both companies told CNBC on Monday.

Aetna's current CEO, Mark Bertolini, will remain on the company's board, but he won't be in charge of running the Aetna unit.

Bertolini took over as CEO of Aetna in 2010 and has been a champion for wellness at the company, a passion driven by his own health scares. Bertolini tackled one widespread issue in the business world, sleep deprivation, by creating an incentive program that pays employees to get more sleep.

"If they can prove they get 20 nights of sleep for seven hours or more in a row, we will give them $25 a night, up $500 a year," he said in an interview on CNBC's "Squawk Box" in 2016.

Bertolini believes that sleep is crucial to performing well at work. "Being present in the workplace and making better decisions has a lot to do with our business fundamentals," he told "Squawk Box."

"You can't be prepared if you're half-asleep," he said, saying he has the numbers to back up his assertion that better sleep can lead to bigger profits.

Bertolini's not the only business leader who's putting sleep first: Jeff Bezos, Sheryl Sandberg and Arianna Huffington all have packed schedules as well, but you won't catch them burning the midnight oil.

In addition to Bertolini, CNBC rounded up six other super successful people who all prioritize sleep.

Jeff Bezos

Amazon's Jeff Bezos makes a point of getting enough sleep every single night.

"Eight hours of sleep makes a big difference for me, and I try hard to make that a priority," he tells Thrive Global. "For me, that's the needed amount to feel energized and excited."

Adequate rest not only leaves Bezos invigorated for the day to come but allows him to continuously make sharp, thoughtful choices without suffering from decision fatigue. That's what can happen when choices become harder as a day goes on and you deplete your finite store of energy.

"Mostly, as any of us go through our lives, we don't need to maximize the number of decisions we make per day," Bezos explains. "Making a small number of key decisions well is more important than making a large number of decisions. If you shortchange your sleep, you might get a couple of extra 'productive' hours, but that productivity might be an illusion."

Eric Schmidt

While many powerful leaders pride themselves on how little they can sleep, Alphabet's executive chairman Eric Schmidt says that "the real secret is the most successful people have awareness of what their body needs and sleep whenever necessary."

In an essay for Thrive Global, Schmidt points out that getting enough sleep permeates every aspect of your life, including your eating habits, decision making skills and "physical and mental ability to do almost everything."

"If one is too tired to consider butterfly effect of their actions, they could set themselves up for quantum chaos," he writes. "We all know that feeling when we are awake, productive, full of energy and happy to be alive. Those are the days when the fabric of life twists and turns in our favor, being productive is easy, and nothing can stop you."

Bill Gates

In 1997, Bill Gates wrote about how he envied people who can survive on only three or four hours worth of sleep, but he has since changed his tune.

Gates admits that, although he can give a speech without much sleep, he is unable to think creatively if he isn't well-rested.

"I used to work all night in the office, but it's been quite a while since I lived on catnap," he says in a Microsoft FAQ. "I like to get seven hours of sleep a night because that's what I need to stay sharp and creative and upbeat."

Sheryl Sandberg

Facebook COO Sheryl Sandberg says it's important for business leaders to take steps to ensure their employees are getting enough sleep.

"We have to acknowledge that not everyone can get the sleep they need," Sandberg writes on Thrive Global. "So many people out there, so many single mothers and others, work multiple jobs, and we don't have the safety net we need for people to make sure that they can take care of their own health, and that we help take care of them."

"It's incumbent upon all of us who run companies, and all of us, to make sure that people can make ends meet and have the ability to get a good night's sleep," she adds.

Arianna Huffington

After collapsing from exhaustion and breaking her cheekbone 10 years ago, Arianna Huffington realized that she need to make some changes in her life.

"That was the beginning of my realizing that millions of us are living under the collective delusion that we need to burn out in order to succeed," she said during an interview with CNBC.

The Huffington Post founder started researching the intersection of sleep and productivity and even wrote books on the topic: "The Sleep Revolution" and "Thrive."

Now, she follows a strict four-step ritual before going to bed every night to ensure good sleep. Huffington's routine includes leaving her devices outside of the bedroom and wearing items specifically for sleep — not loungewear or gym clothes.

Satya Nadella

Microsoft CEO Satya Nadella follows in the footsteps of the company's founder in more ways than one: Like Gates, he also makes getting good sleep part of his routine.

During a Q&A with ABC in 2015, Nadella revealed that he wakes up at 7 a.m. and gets eight hours of sleep per night.

While a 7 a.m. wake-up call might seem early to some, it's indulgent compared to some of Nadella's fellow Silicon Valley executives. As the Huffington Post points out, it's several hours later than Apple CEO Tim Cook, who has been known to rise as early as 3:45 a.m.

This is an updated version of a previously published article.

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