Prolonged Sitting: Why It's Bad For Your Health Alex and Laila / Getty Images It's time to get off your keister. Another study finds that sitting for too long increases your risk of death, even if you exercise regularly. Suddenly, those treadmill desks are sounding more appealing. The study found that adults who sat for 11 hours or more a day had a 40% increased risk of dying in the next three years than those who sat for less than four hours a day. Even after taking into account physical activity, weight and health status, researchers found that the unsettling association held. That morning walk or trip to the gym is still necessary, but it's also important to avoid prolonged sitting. Our results suggest the time people spend sitting at home, work and in traffic should be reduced by standing or walking more," study author Dr. Hidde van der Ploeg, a senior research fellow at the University of Sydney's School of Public Health in Australia, said in a statement. The study results come from the Sax Institute's 45 and Up Study, the largest ongoing study of healthy aging in the Southern Hemisphere. VIDEO: Walking While Working: The Treadmill Desk in Action In the study, more than 200,000 people answered questionnaires about the amount of time they spent sitting per day. The participants were split into groups based on their hours spent sedentary: less than 4 hours, 4 to 8 hours, 8 to 11 hours, and 11 or more hours. Regardless of other health factors, sitting for extended periods of time was associated with higher risk of death. According to the researchers, the adverse effects of prolonged sitting are caused mainly by disrupted metabolic functions that lead to worse vascular health. "Prolonged sitting has been shown to disrupt metabolic function resulting in increased plasma triglyceride levels, decreased levels of high-density lipoprotein cholesterol, and decreased insulin sensitivity," says Dr. van der Ploeg in an email. Basically, lack of movement triggers really unhealthy metabolic changes. Although active people may also be harmed by extended sitting sessions, maintaining a consistent exercise regime is still a great benefit. Physically inactive people who reported sitting the most had double the risk of dying within three years, compared with active people who reported sitting the least. Among the sedentary group, people who sat the most had a nearly one-third higher chance of dying than those who sat the least. "For people who are regularly physically active, those who sit less have a lower risk of dying than those who sit more," says Dr. van der Ploeg. However, active people have a lower risk of dying compared to those who are physically inactive. So it is still very important to meet the physical activity recommendations of 30 minutes per day of at least moderate intensity physical activities - such as walking - for adults and 60 minutes per day for children. MORE: The Dangers of Sitting at Work - and Standing We already know that vegging out on the couch for hours to watch TV doesn't do the body good. Doctors have preached that for ages. But what if your 9-to-5 job requires you be chained to your desk? Try ways to break up your sitting and add in more standing or walking where possible. For example, try standing up while on the phone or have a stand-up meeting," says Dr. van der Ploeg. Several workplaces in the Sydney area are trying sit-stand workstations, and they are generally well received, so this might be the future for workplaces. It is also important to sit less outside of work, says Dr. van der Ploeg. The average adult sits for 90% of their leisure time, so it seems there is some room for improvement. You don't have to stand or walk for 100% of your leisure time of course, as sitting is very comfortable. But try to find a healthy balance between sitting, standing and walking or other physical activities. The study was published March 26 in the Archives of Internal Medicine. MORE: The Science of Children's Bedtime MORE: No Clots in Coach? Debunking "Economy Class Syndrome"