Here is yet another study to add to those demonstrating that physical activity is associated with a lower risk of chronic disease. Causality for this link is well demonstrated in laboratory animals, but human studies must use statistical methods on a population, or track large numbers of people for decades, which makes it more challenging to prove that exercise causes better health. Given the weight of evidence at this point, however, that exercise improves health is a good working assumption.
The paper for this study is open access and linked in the release materials quoted below:
People who decrease sitting time and increase physical activity have a lower risk of chronic disease. Even standing throughout the day - instead of sitting for hours at a time - can improve health and quality of life while reducing the risk for chronic diseases such as cardiovascular disease, diabetes, heart disease, stroke, breast cancer and colon cancer, among others.
The researchers studied a sample of 194,545 men and women ages 45 to 106. The data was from the 45 and Up Study, which is a large Australian study of health and aging. "Not only do people need to be more physically active by walking or doing moderate-to-vigorous physical activity, but they should also be looking at ways to reduce their sitting time." Sitting for prolonged periods of time - with little muscular contraction occurring - shuts off a molecule called lipoprotein lipase, or LPL. Lipoprotein lipase helps to take in fat or triglycerides and use it for energy.
"We're basically telling our bodies to shut down the processes that help to stimulate metabolism throughout the day and that is not good. Just by breaking up your sedentary time, we can actually upregulate that process in the body."