Health Risks of Prolonged Sitting

There are many controllable lifestyle factors known to have a detrimental effect on our health, including poor diet, tobacco use, and lack of exercise. However, prolonged sitting, or sedentary time, has been getting a lot of recent attention and may be just as harmful as these usual suspects. Thanks to our modern society, it’s not uncommon for individuals to sit for 8+ hours a day at work or school and then spend evenings and free time engaged in other types of sedentary behavior, such as watching TV or playing video games. Research has shown that this prolonged sitting time, independent of physical activity, is linked with increased mortality from all causes and numerous chronic health conditions including cardiovascular disease, certain cancers, type 2 diabetes, metabolic syndrome, and obesity. [1,2,3]

A study of NHANES data examined sedentary time and amount of breaks from sitting using ActiGraph accelerometers.[4] When subjects in quartile 4 were compared to those in quartile 1 for total sedentary time, they had significantly higher waist circumferences, systolic blood pressure, fasting triglycerides, and insulin levels. Comparing the subjects in quartile 4 to quartile 1 for total amount of breaks in sedentary time, they had significantly lower values for waist circumference and C-reactive protein, an inflammatory marker associated with several major diseases. Researchers found that the more breaks the subjects took from sedentary time, the lower the levels of C-reactive protein. This study demonstrates the health risks of prolonged sitting and how important it is to take time to move throughout the day.

Breaking the pattern of sedentary behavior may be even more important for children and adolescents, as research has indicated that their behaviors have a strong influence on their health as adults. A Spanish cohort study examined physical activity and sedentary time in children and adolescents, and compared these values to those collected 6-10 years later when the subjects were young adults. They found that as subjects got older, physical activity levels went down and sedentary time increased. [5] As technology advances, we have started seeing trends of children spending less time involved in physical activity and more time watching TV or playing video games. These increases in screen time as an adolescent may result in greater BMI gains later in life. [6,7]