For the new study, published in The Lancet Public Health in April, researchers from the Norwegian School of Sport Science in Oslo and other institutions decided to dig as deep as possible into lifestyle and work in the workplace, and lifespan.
They started with data already collected by Norwegian health authorities, who have been conducting studies to measure the health of hundreds of thousands of Norwegians for decades. These data included detailed information about their work and movement history, education, income, and other aspects of their life.
The researchers now compiled data sets from 437,378 participants in these studies and categorized them according to occupational types. Some, like clerks or inspectors, would walk and lift at work; others did heavy manual labor; and the rest more or less sat at the desk all day. The researchers then compared people's records to decades-long databases tracking diseases and deaths in Norway.
In the first run, their results reinforced the idea that active jobs shorten life. Over the course of approximately 30 years, sedentary men outlived those who often walked or otherwise exerted themselves at work. (There was still no significant link between women's occupations and their longevity.)
But when the scientists scrupulously checked everyone's education, income, smoking, exercise habits, and weight, the associations turned around. In this more in-depth analysis, men who were professionally active were less likely to develop heart disease and cancer than desk-bound men. Regardless of whether they walked a fair bit to get to work or did other, more strenuous work, active men lived on average about a year longer.
In essence, the study shows that “every movement counts, regardless of whether you are active at work or in your free time,” says Ulf Ekelund, professor at the Norwegian School of Sports Science who oversaw the new study. Conversely, the results also remind us that sitting, even at comfortable desks or on comfortable sofas, is unhealthy.
What this study does not tell us is what aspects of our life outside of work could most affect our health and longevity, or why women's lifespans in general seem unaffected by the exertion of work hours. Dr. Ekelund and colleagues hope to examine some of these questions in future research. But for the time being, he says, assume "that any physical activity is beneficial, whether it's in your free time, at work, at home or during transport."