Does sitting all day increase your risk of heart problems?

Sitting a lot increases your risk of heart problems, even if you exercise regularly otherwise. A meta-analysis of nearly 1.4 million participants showed that people who sit the most have a 30% higher risk of cardiovascular disease than people who sit the least. Each additional hour of sitting per day corresponds to roughly 5% extra risk.

There appears to be a clear tipping point at around 6 to 8 hours per day. Above that threshold, the risk of death from heart problems rises by about 4% for every extra hour. People who sit for more than 10.6 hours per day have a 45% higher risk of heart failure and a 62% higher risk of dying from heart problems, compared with people who sit for 8 to 9.5 hours per day. The risk of a cardiac arrhythmia and a heart attack is also elevated with that much sitting, although that association is somewhat less pronounced.

Exercise helps, but does not fully resolve the problem. People who move enough each week (at least 150 minutes of brisk activity) but still sit for more than 10.6 hours per day still have an elevated risk of heart failure. Sitting is therefore an independent risk factor, regardless of how active you otherwise are.

Good news: small adjustments already make a difference. People who normally sit for more than 10.6 hours per day can lower their risk of heart failure by 7% by sitting 30 minutes less each day, regardless of what replaces that sitting time. Converting one hour of sitting per day into light movement, such as gentle walking or standing while working, lowers the risk of cardiovascular disease by approximately 16%. Sitting less is therefore beneficial even for people who already exercise enough.