Spending the day in an office chair can lead to a buildup of fat around the heart, according to a new study out of the United States, and it won’t go away with regular exercise.

The longer the time you spend sitting down – whether it’s in an office or on a couch – the bigger the area of fat, said study author Britta Larsen.

Larsen presented her findings at the American Heart Association in Los Angeles this week.

Larsen explained that the type of fat found around the heart, pericardial fat, “is strongly related to cardiovascular disease. It gets in the way of heart function, it clogs up your arteries — you don’t want it there.”

CT scans of more than 500 older Americans found that excess time spent sitting “was significantly related to pericardial fat around your heart,” Larsen said.

“Even if you run every day but then you sit for eight hours a day, the sitting is still doing something bad for your health,” Larsen said in a statement.

She also noted that studies have found sitting to be detrimental to health even after scientists factored out excess weight gain.

Prolonged sitting was not significantly related to any of the other types of fat, the study found.

According to the study, regular exercise was not related to a lessening of pericardial fat, although it did help reduce visceral fat around the organs, which is strongly tied to diabetes and metabolic disease.

The study “really emphasizes that [sitting and exercise] are two distinct behaviors,” Larsen explained. “In order to really be healthy you need to focus on both — get enough exercise but also not sit for 10 hours per day like most of us do.”

Tips for combating the buildup of pericardial fat include taking regular walks during work hours, taking the stairs instead of the elevator and using a stand-up desk.