How many hours do you work every week? Take just a moment and figure out your average. Be careful, though: I want you to include all of your time spent working. Not just the hours that you’re in the office, but the time it takes to check your email while watching TV, or responding to a quick text from a co-worker.  

You’re not done yet, though. Now add up all of the time that you spend doing non-work activities while on the job. Any time that you’ve scanned through movie reviews or celebrity news on the internet, or done a little online shopping, or called your partner to ask what they want to have for dinner. More than half of all online purchases are made between 9 a.m. and 5 p.m., and almost two-thirds of traffic on porn sites happens during the work day. When you add all that up, subtract it from your working hours. What is the final total? 

If you don’t really know how much time you spend not working while on the job or working while not on the job, you are not alone. Most of us feel stressed and overworked, but cannot accurately say what our average week looks like. Our jobs have oozed into our homes and left sticky trails of stress and anxiety all over our floors and couches.  

Regardless of the numbers, most people in the U.S. work more than 40 hours a week. What’s more, they are convinced that hard work leads to success. In a Pew Research poll, about 60 percent said that, for the most part, people who want to get ahead can do so if they work hard enough. Culturally, we have strong beliefs about hard work and long hours. When someone asks how we are, we say “busy.” 

Many have told me they put in long hours because it’s necessary to get the job done and because they think their labor will eventually be noticed and rewarded by management. It’s possible that you work in a place where excessive hours are expected. As they say, you can’t reward what you can’t measure. Hours spent at the desk are measurable and so sometimes they are included in a supervisor’s estimation of your commitment to the company.  

Let’s dig into that first assumption for a moment, though, that working long hours results in more work accomplished. I’m sure that seems like a no-brainer: The more you work, the more work you produce. But that’s not actually true. And we’ve known that for a very long time.  

Back in the 1920s, Henry Ford noticed that when his employees worked too much, their productivity sank and the number of errors skyrocketed. That’s why Ford decided to mandate an eight-hour day and a five-day week. He said: “We know from our experience in changing from six to five days and back again that we can get at least as great production in five days as we can in six. Just as the eight-hour day opened our way to prosperity, so the five-day week will open our way to a still greater prosperity.” Remember, Ford didn’t invent the car. His greatest innovations were connected to increases in efficiency, and he simply discovered that long hours are inefficient.  

Nearly a century later, Ford’s conclusion has been proved correct over and over again. It reminds me of something called Parkinson’s Law which states that work expands to fit the time available. So, if you know you only have two hours to write an agenda, research shows that task will take two hours. If you have four hours to do it, that same task will suddenly require twice as much time.  

In 1951, two men at the Illinois Institute of Technology kept track of nearly 200 of their colleagues in the scientific and technical fields. They found that those who put in excessive hours were the least productive of all. After people passed a couple dozen hours in the lab, they saw decreasing returns on their labor. In fact, the most productive of the group were those who put in between 10 and 20 hours a week, or two to five hours a day.  

The truth is, overwork reduces productivity. The Greeks work more hours than any other European, according to data from the OECD. And yet, they rank 24th out of 25 nations for productivity. We have data on this going back to the 1800s — when employers were forced to put limits on working hours, factory owners were surprised to find that productivity increased while accidents decreased, just as Ford found half a century later. Let’s look at a more modern example, though.  

In 2015, administrators at one of the largest hospitals in Europe were concerned about burnout among staff, and they decided to cut work hours for the orthopedic unit.   

More than 100 nurses and doctors at Sahlgrenska University Hospital started working six-hour days. I’m sure you can imagine how revolutionary that decision was in an industry well known for its punishing schedules, where cots are set up in break rooms so  nurses and residents can snatch a catnap from time to time.   

I’m willing to bet that administrators were nervous about the experiment and they said they were prepared to add a bunch of new staff members. But since cutting down shifts, the orthopedic unit has become more productive and efficient, not less so. The executive director says sick days have been slashed to almost nothing. He also says that unit is performed 20 percent more operations and generating additional business. Patients used to wait months for surgery, but can now head to the O.R. within a few weeks. There are examples of this in a variety of industries. Allowing yourself enough time to rest and refresh is ultimately a productive choice. In fact, a survey of consultants revealed that managers couldn’t tell the difference between employees who put in 80 hours of work and those who didn’t because there was no discernible difference in output.  

Repeated studies show that taking time off boosts productivity, creativity, and problem-solving. It can even strengthen your immune system, making it less likely that you’ll get sick and be forced to stay home with a cold. We’ve also found that workers who feel more detached from their jobs while they’re at home are emotionally healthier, report getting better sleep and are less likely to be emotionally exhausted. They are more prepared and ready every morning to dive into their work than those who are writing memos at 10 p.m.  

So, for maximum productivity, stop working excessive hours and stop bringing your work home with you. Most emails are not urgent and do not need to be answered in the evening or over the weekend. Your brain needs a real break so you can be fresh and healthy by Monday. It’s possible that stepping away from your work is the most productive action you can take.  

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