You’ve probably heard that living a sedentary life increases your risk of diabetes, obesity, kidney disease, cardiovascular disease and premature death. That is true even if you exercise regularly, but otherwise spend your day sitting in a chair. Since in today’s modern world, most of us sit for hours doing our jobs, how can we protect ourselves? A new study offers some hopeful perspective.
Dr. Srinivasan Beddhu, a professor of medicine at the University of Utah, led the study. Researchers analyzed data available from the annual National Health and Nutrition Examination Survey. In recent years, some participants have begun wearing monitors to trace their movement patterns.
The research team gathered monitor data for 3,626 adult male and female subjects, most of whom reported being in good health at the beginning of the study period.
The researchers divided each of the participant’s days into blocks of time: minutes spent sitting, minutes spent in low-intensity activity, minutes spent in light-intensity activities (such as walking around the room), and minutes spent in moderate to intense activities like jogging.
Most of the participants’ time was spent sitting.
Researchers then investigated death records for three or four years following the survey, and used the resulting numbers to analyze the participants’ overall risk of early death, and how sitting or not sitting may have influenced the outcome. They wanted to see what activity – standing, walking or jogging – was most likely to extend lifespans.
They were somewhat surprised to learn that standing, by itself, did little to protect against premature death. However, those participants who walked around after standing, replacing the time otherwise spent sitting with light-intensity activity like gentle walking, actually reaped a substantial health benefit in terms of lower mortality risk.
In fact, people who substituted strolling for sitting as little as two minutes every hour lowered their risk of early death by about 33 percent over people who sat the whole hour.
An additional reduction in mortality was found among people who did moderate exercise. However, because so few participants chose to jog or do other moderate or high-intensity activity, the statistical variation was insignificant.
Dr. Beddhu characterized the findings as “encouraging.” He said the benefits appear to be additive; if someone walks two minutes an hour, then adds two more minutes, his or her risk of premature death is reduced even more.
Dr. Beddhu speculates the reduction in mortality risk is probably related to energy balance. Slow walking, rather than sitting, increases the number of calories burned. This in turn potentially contributes to weight loss and positive metabolic changes.
This study is observational, so while it clearly demonstrates an association between the 2-minute walk and lower mortality risk, it does not prove causality. Nevertheless, you may want to build that little walk every hour into your work day. Share this information with your boss and co-workers, make it a group activity!