There are several remedies to overworking. For instance, many of us believe we need to be in the office both when our boss shows up and when he or she leaves. However, Vanderkam thinks that’s a big (and often misguided) assumption. “Maybe your boss wants the place to herself in the morning and she’s actually annoyed that you’re getting there early, too.”

Vanderkam also thinks a lot of people aren’t willing to consciously build breaks into their daily schedule out of fear they won’t be seen as hard workers. “So we sabotage our own productivity by saying ‘I’m just going to work all day, have my lunch at my desk, and fall into the 2:30 pm rabbit hole of the internet’,” she explains.

A silver lining

While trading rest for unpaid overtime is clearly a bad deal for employees, it’s actually pretty lousy for employers, too. A Stanford University study found that employee output declines sharply after 50 hours per week and nosedives after 56 hours to the point where someone who puts in 70 hours doesn’t produce anything more with those additional 14 hours. Similar studies have linked long hours with absenteeism, long-term memory loss and impaired decision-making skills.

So what are companies doing to combat the inevitable burnout? Major Japanese corporations have actually taken a lead on the issue. Toyota now limits overtime to 360 hours a year (or an average of 30 hours monthly), while ad agency Dentsu just released an eight-point plan (including regular vacation encouragement and lights out at the office by 22:00) to improve its work environment after the high-profile suicide of one of its employees.