Headlines during the past few years have been pretty emphatic, “Sitting is the new smoking,” they warn in an anything but subtle way. Here’s just one example of the kind of messaging being used to try and get people up out of chairs.
With the mounting evidence correlating sit time with poor health outcomes (and this is independent of exercise), we’ve seen everything from a new Surgeon General’s Call to Action on walking, to entirely new companies trying to equip our homes, workplaces, and schools with standing or sit-stand desks.
Now, I’ll be the first to admit, I notice a difference when I sit too much. My muscles shorten, causing stiffness, especially in the same ones I call on when swimming, cycling or running. My energy diminishes with time. My focus wains.
In terms of the long-term impact on my health, though, whether prevention of heart disease or improving life expectancy, that’s an entirely different and more difficult question to answer.
But, researchers from the UK tried to do just that, conducting one of the longest follow-up studies (16 years) for this area of research with more than 5,000 participants (3720 men and 1412 women).
Participants, who were between the ages of 35 and 55 from the Whitehall II study of British Civil Servants, were asked to report on average how many hours per week they spent sitting at work including driving or commuting, and sitting at home (e.g., watching TV, sewing, working at a desk). They were asked to select one of eight categories: none, 1 h, 2–5, 6–10, 11–20, 21–30, 31–40, 40 h+.
Researchers then correlated self-reported sitting with mortality, which was established through the national mortality register kept by the National Health Service (NHS) Central Registry.
Here’s what they found.
The table below looks at all-cause mortality according to categories of sitting behavior. The main take-away? For each of the categories of sitting behaviors, there was no link with all-cause mortality during the 16-year follow-up period.
In the study, the researchers provide a few possible theories to explain their divergent findings from those of past research. One plausible explanation is that the long periods of sitting are also counterbalanced by the higher levels of activity reported by participants of the Whitehall II study. This is especially evident with walking and standing, especially for commuting. Also, study participants were mainly healthy, white collar workers. Meaning, there are likely other protective health factors in their environment.
The big thing to remember though with the study population is that the study can’t draw conclusions for how prolonged sitting might influence or not influence all-cause mortality among unhealthy or higher risk populations.
Nonetheless, the study adds to the rapidly growing debate on the role of sitting and physical activity, and health. Specifically, it further contributes to policy conversations around workplace wellness, and the extent to which (or not) sit-stand desks and other strategies to minimize sitting should be used.