What happens when we cut our work hours a little, perhaps by deciding to firmly stop working at a specific time and go home? An obvious assumption is that we’d be less productive because if we work fewer hours, then we have few hours to be productive. But a year-long study (von Thiele Schwarz and Hasson, 2015) found that people who had cut their weekly work hours by a mere 6.25 percent got more done than a control group who continued working as usual.

The study was actually trying to prove something else entirely, but it didn’t work. The researchers were hoping to prove that getting more physical activity, even if it was a tradeoff to working, would improve employees’ productivity overall. But that wasn’t what happened at all.

Here’s the setup: A group of 177 dental health care workers were put into three groups. One was the control group. Nothing changed about their work. The next group had to swap 2.5 of their working hours each week for physical exercise, which they had to do at work. The final group had their work hours cut by 2.5 hours per week, but they didn’t have to do any exercise. They could just go home earlier. They’re called the reduced work hours (RWH) group. The results are startling.

The RWH group increased their productivity, on average, by 13.4 percent!

“RWH demonstrated the greatest increase in number of patients per therapist, 13.4%, followed by referents [control group] (5.4%) and PE (1.3%). This can be compared with the organization as a whole, where the increase was 2.9%. For RWH and referents, the greatest increase in production was during the first half of the intervention period (RWH: 5% increase during the first half followed by a 3% decrease during the second half; Referents 13% increase followed by a 7% decrease), while PE showed an opposite pattern (4% decrease followed by a 8% increase). This was similar to the development in the organization as a whole (no change [0%] followed by a 7% increase).”

Caveats

When I read the study, a few red flags went up for me. For one, about 90 percent of all the subjects were female. That’s terribly imbalanced.

Second, the study takes place in Sweden, where the population tends to be more active than, say, Americans or the British. The reason I bring up that fact is because there’s no assessment of how much physical activity the subjects are already getting outside of work. For example, if it turned out that the PE group comprised individuals who were already jogging seven miles every day and going skiing most weekends, it’s possible that an addition 2.5 hours per week of mandated exercise might just make them more tired.

Additionally, it’s important to remember that these are dental health care workers, so we’re talking about a population that doesn’t sit still in front of computers for hours at a time. Dental workers move around a lot. So they’re not as prone to being sedentary for long periods of time the way knowledge workers are.

In any event, the study did take place over the course of a year, so that’s helpful in terms of trusting the results.

What Can You Do?

There’s a theory that when people have limited time, they manage it better. One of my favorite sayings is, “If you want something done, give it to a busy person.” And there’s evidence of it. When I was younger and starting college, I remember being told that students who work while attending university tend to have higher grade point averages than those who don’t work. Plenty of research, including Dundes and Marx (2006) backs up the claim.

It’s only to a point, though. In the case of students, the stat holds true for those who work no more than about 19 hours per week.

Moderation is an important takeaway from the study on dental workers as well. Remember, they only cut their working time by 2.5 hours per week. If they cut it drastically more, surely there’s a point when their productivity would drop. But because it’s only a small cut, it seems to help them manage their time more efficiently and get more done.

So what can you do? Pick a time to wrap up work, and stick to it. (It doesn’t have to be 5:00 p.m.) Forcing yourself to go home may be exactly what you need to light a fire under yourself to get more done during the rest of the day.

References

Dundes, L. and Marx, J. (2006). Balancing Work and Academics in College: Why do Students Working 10­19 Hours Per Week Excel? Journal of College Student Retention, 8(1) 107­-120.

von Thiele Schwarz, U., & Hasson, H. (2015). Employee Self-rated Productivity and Objective Organizational Production Levels Journal of occupational and environmental medicine.