Health risks of prolonged sitting

Spending too much time sitting every day is not healthy for you. Prolonged sitting, i.e. sedentary activity, can be defined as sitting for 8 to 12 hours or more a day (CNN). A new article, which is a meta-analysis of 47 previous studies, reports on the association between sedentary time and mortality, cardiovascular disease, cancer, and diabetes. The results were startling.

Overall there was a 24% increase in all-cause mortality risk for those who sat for long periods of time. This increase was observed for both cardiovascular disease mortality (18% increase) and cancer mortality (17% increase). The greatest effect was for type 2 diabetes incidence in which there was almost a two-fold rise (91% increase) in risk for those with a sedentary lifestyle.

The outcomes were generally "more pronounced at lower levels of physical activity than at higher levels." However even those who engaged in the recommended daily amount of exercise still had a higher mortality rate if they sat for long periods of time compared to those who sat less. Thus, regular exercise only partially offsets all of that sitting.

Figure 1 shows how all of that sitting can add up so that the average adult spends more than half of their day sitting.

So what can we do? Dr. David Alter, senior author of the paper, suggests the following (LATimes):

"While working at a desk, be sure to get up for one to three minutes every half-hour or so and move around. While watching TV, stand or exercise during the advertisements (and no, don't go stand at the open fridge or the pantry). Monitor how much you sit, and try to reduce it by realistic increments every week. You should aim for two to three fewer sedentary hours in a 12-hour day. A wearable monitor can help establish a baseline and assess progress toward a goal. Know that getting regular exercise is good for you regardless of what you do for the rest of the day: It will not only help reduce your sedentary time, it should lower your risk of illness and improve your survival prospects if you have no alternative to logging long hours in a chair."

In a nutshell, get up and walk around 1 to 3 minutes for every half hour of sitting. Monitor how much you sit each day, and try to reduce the amount by 2 to 3 hours in a 12 hour day (i.e. you want to sit less than 8 hours per day). Finally, strive to obtain the recommended daily amount of exercise.

Figure 1. Time to get off your fanny; sit less and move more!