eople who spend much of their day sitting may need to move around less than we thought to counteract their sedentary lifestyle, new research shows.
Our research, published today in the Journal of the American College of Cardiology, found about 20-40 minutes of physical activity a day seems to eliminate most health risks associated with sitting.
That's substantially lower than the one hour a day a previous study has found.
We spend almost all our waking day sitting, standing, or moving. The health impact of each one of these can be complex.
For example, too much standing can lead to lower back problems and even a higher risk of heart disease. But sitting for too long and not moving enough can harm our health.
Then there are people who sit for many hours and also get in reasonable amounts of physical activity. For example, someone who has an office job but walks to and from work for 20 minutes each way and runs two to three times a week easily meets the recommended level of physical activity.
While we know moving is better than sitting, what is far less clear is how much of a good thing (moving) can offset the harms of a bad thing (sitting).
That's what we wanted to find out in our study of almost 150,000 Australian middle-aged and older adults.
We followed people enrolled in the 45 and Up Study for nearly nine years. We looked at links between sitting and physical activity with deaths from any cause, and deaths from cardiovascular disease such as heart disease and stroke, over that time. We then estimated what level of moderate-to-vigorous physical activity might offset the health risks of sitting.
This kind of activity is strenuous enough to get you at least slightly out of breath if sustained for a few minutes. It includes brisk walking, cycling, playing sports or running.
He has a very sedentary job.
He became increasingly sedentary in later life.