Here's what CEOs actually do all day

Ever wonder what CEOs actually do all day? A study published on Monday by Harvard Business Review sheds light on how those in the top spot use their time.

The study, launched in 2006 by Harvard professors Michael Porter and Nitin Nohria, tracked how 27 CEOs (only two women and 25 men) of companies with an average annual revenue of $13.1 billion spent their days. Data was collected from the CEOs in 15 minutes increments, 24 hours a day, seven days a week for three months. Overall, the study collected 60,000 CEO hours.

It reveals, on average, the leaders worked 9.7 hours per weekday, which totals just 48.5 hours per workweek. They also worked 79 percent of weekend days at an average of 3.9 hours daily, and 70 percent of vacation days with an average of 2.4 hours on those days. Altogether, the study found that CEOs worked an average of 62.5 hours a week.

(The average American works 44 hours per week, or 8.8 hours per day, according to the Bureau of Labor Statistics, with nearly a third reportedly working on the weekend.)

"We found that, indeed, time is the scarcest resource" for CEOs, Porter told CNBC.

Seventy-five percent of a CEO's time, on average, was scheduled in advance, while 25 percent was spontaneous.

But big picture, it seems the CEOs struck a balance between work and personal time: 31 percent of their time was spent working, 10 percent commuting, 25 percent was personal time (awake, but not working, including family and down time), 29 percent was spent sleeping (on average, they clocked 6.9 hours a night) and 5 percent was spent on vacation.

So what are the chief executives actually doing with their day?

The study found that a CEO's work is diverse: 25 percent of their work is spent on people and relationships, 25 percent on functional and business unit reviews, 16 percent on organization and culture, and 21 percent on strategy. Only 3 percent of their work is spent on professional development, and only 1 percent on crisis management. Meanwhile, 4 percent of their work is on mergers and acquisitions, while another 4 percent is spent on operating plans.

And even CEOs are plagued by not-so-efficient meetings.

Meetings make up a big bulk of a CEO's day too; 72 percent of their work time is spent in meetings, compared to 28 percent alone time. Thirty-two percent of the CEOs' meetings lasted an hour, 38 percent were longer than that and 30 percent were shorter.

"In our debriefs, CEOs confessed that one-hour meetings could often be cut to 30 or even 15 minutes," Porter and Nohria wrote in Harvard Business Review.

The study also found CEOs value face-time: 61 percent of their communication was face-to-face, while only 24 percent was electronic (like email), and 15 percent by phone and letter.

"Face-to-face interaction is the best way for CEOs to exercise influence, learn what's really going on, and delegate to move forward the multiple agendas that must be advanced. It also allows CEOs to best support and coach the people they work closely with," the researchers wrote.

"How a CEO spends face-to-face time is viewed as a signal of what or who is important; people watch this more carefully than most CEOs recognize."

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