A 2013 study published in the Journal of the American College of Cardiology reviewed 12 years worth of data from more than 71,000 postmenopausal women enrolled in the Women’s Health Initiative (WHI). The researchers found that those who sat for 10 hours or more each day had an 18 percent higher risk of developing a heart attack or stroke, compared to those who only sat for five hours or less, regardless of their level of physical activity. And while the study focused solely on older women, the researchers say the results can be applied to the general population, regardless of age or sex. “There is no reason to believe that prolonged sitting would not increase risk in all adults. Previous studies in other populations support this,” lead study author Andrea K. Chomistek, MPH, a research fellow at the Harvard School of Public Health, said in a statement. And for more on your risk of experiencing a cardiovascular event, If You See This in Your Mouth, Your Heart Attack Risk Is High, Study Says. According to the study, women who had low levels of physical activity overall had the largest increased risk. Only 18 percent of those who reported high levels of physical activity said they sat for 10 or more hours a day, while 32 percent of those who were more inactive reported sitting for this long each day. The researchers found that those who reported the lowest levels of physical activity had a 63 percent higher risk of having a heart attack compared to active women who sat five or less hours per day. According to the study, this “shows that it might be beneficial to participate in regular exercise despite engaging in other potentially detrimental behaviors, like prolonged sitting.” And for more useful information delivered straight to your inbox, sign up for our daily newsletter. While the study did not directly determine the link between sitting and heart attack risk, Chomistek said that “physiological responses associated with prolonged sitting, such as suppression of skeletal muscle lipoprotein lipase activity” and “reduced glucose uptake,” might give insight into how sedentary behavior can increase this risk. She said that while reducing sitting time would be beneficial to decreasing this risk, so would “taking breaks during prolonged periods or sitting” by standing up and taking short walks. “For individuals who are unable, or averse, to exercise, amount of time spent sitting may be more amenable to change than increasing levels of physical activity,” Chomistek said. And for more ways you could be putting your health in danger, This Is the One Vitamin You Should Never Take, Doctors Say. According to the Centers for Disease Control and Prevention (CDC), someone in the U.S. has a heart attack every 40 seconds. This amounts to almost 805,000 Americans having a heart attack every year, with nearly 605,000 of those being an individual’s first heart attack. And about one in five heart attacks is silent, meaning that damage to the heart occurs and you may not even realize it. However, if you do have symptoms, these can include chest pain or discomfort (most likely in the center or left side of the chest), weakness, light-headedness, pain or discomfort in the jaw, neck, back, one or both arms, or shoulders, and shortness of breath. If you notice any of these symptoms, you or someone else should call 911 immediately, as the “chances of surviving a heart attack are better the sooner emergency treatment begins,” per the CDC. And for more on your heart attack risk, If You Have This Blood Type, Your Heart Attack Risk Is Higher, Study Says.ae0fcc31ae342fd3a1346ebb1f342fcb