New research has shown that sitting in front of the TV for too long can increase the risk of potentially fatal blood clots by up to 70% – findings that might make you think twice before watching all the episodes of Stranger Things in one go.The scienceScientists in the US looked at the data of more than 15,000 middle-aged people who were taking part in the Atherosclerosis Risk in Communities Study. It was found that the risk of developing a venous thromboembolism – a vein condition that usually affects the legs, arms and/or pelvis, and can also cause clots in the lungs – for the first time was: 1.7 times higher in those who reported watching TV "very often", compared to those who watched TV "never or seldom." 1.8 times higher in participants who met the recommended guidelines for physical activity and reported watching TV "very often", compared to those who watched TV "never or seldom."Increased with more TV viewing both for life-threatening clots in the extremities and those in the lungs; and while obesity was more common in people who watched more TV. Study co-author and Professor Mary Cushman, of Vermont University, said:"Watching TV itself isn't likely bad, but we tend to snack and sit still for prolonged periods while watching." She added: "Think about how you can make the best use of your time to live a fuller and healthier life. You could put a treadmill or stationary bike in front of your TV and move while watching. Or you can delay watching TV by 30 minutes while you take a walk. If you must see your favourite show, tape it while you are out walking so you can watch it later, skipping the ads." The reason watching a lot of TV increases the risk of clot it because we don't move our legs while we do it, which slows blood flow to the point of clotting. The clots in question then travel to the lungs where they can turn into blockages known as pulmonary embolisms, which in turn can cause death by cutting off oxygen and blood supply. Prof Cushman warned: "If you are at heightened risk of venous thromboembolism due to a recent operation, pregnancy or recent delivery, cancer or a previous clot, your doctor may prescribe blood-thinning medication or advise you to wear compression stockings." Although the findings need further study and the research has its limitations, previous research has shown that 22 minutes of exercise a day offsets couch potato behavior. It may be a good idea to break up your screen time with a brisk walk.