Do take that break.

A recent study from Wellington Hospital in New Zealand found that office workers who sat for several hours without getting up were more likely to form a deep-vein thrombosis--that is, a blood clot in a vein deep in the leg--than those who moved about more often. Together, deep-vein thromboses and pulmonary embolisms (which occur when a piece of the clot breaks away and blocks blood flow to the lungs) kill upwards of 100,000 Americans each year, or about as many as die from breast, prostate, and colon cancer combined. In this article, Goldhaber, a professor of medicine at Harvard Medical School, explains the connection between DVTs and prolonged periods of sitting anywhere (not just on airplanes) and offers tips for prevention.