Evidence is building that sitting for too long can cause heart disease and diabetes — even in people who exercise, the American Heart Association said Monday.

The trouble is, it’s hard to measure just how inactive people are and there’s not enough evidence yet to show just how much, or how often, you have to exercise to counteract the effects of sitting, the group said in a scientific update.

In the meantime, then, people should try to sit less and move more, the heart association’s team of experts advised.

“The evidence to date is suggestive, but not conclusive, that sedentary behavior contributes to cardiovascular disease and diabetes risk,” a team led by Deborah Rohm Young, of Kaiser Permanente, Southern California wrote.

“Given the current state of the science on sedentary behavior and in the absence of sufficient data to recommend quantitative guidelines, it is appropriate to promote the advisory, ‘Sit less, move more’.”