The Health Effects of a Sedentary Lifestyle
The physical, economic, and social environments in which modern humans operate have dramatically changed since the middle of the last century. These changes have been associated with significantly reduced demands for physical activity.
How Have Things Changed?
Consider the move that we have made from our hunter-gather roots to our modern routines. First we started out as dynamic active individuals who relied on movement and fitness to find nourishment and avoid danger. Once we learned the principals of agriculture, we became farmers who no longer needed to search for our food and relied less on our physical abilities to survive. Fast forward to today, many of us spend the bulk of our days in offices, we can order our meals for delivery and our lifestyles don't require us to be physically fit. A recent study submitted to the National Academy of Sciences demonstrates how these lifestyle changes have affected the average bone density of modern humans. The move from foraging to farming resulted in a significant decrease in bone density.
"There's seven million years of hominid evolution geared towards action and physical activity for survival, but it's only in the last say 50 to 100 years that we've been so sedentary - dangerously so." - Dr. Colin Shaw
These researchers studied the bones of ancient humans and found that their mass and density were around 20% higher than that of their farming descendants. This is the same difference in density that we see in astronauts who have been living without gravity for 3 months! If we project that data forward to our current sedentary lifestyles it is easy to draw the association between inactivity and poorer bone health.
How are we Doing Now?
An Australian study from 2010 by Owen and colleagues coined the term "Active Couch Potato" referring to individuals who meet the daily exercise guidelines proposed by the government (30 minutes per day) but are otherwise sedentary. In their research, these authors examined active couch potatoes and observed the associations between sedentary periods and their effect on health. What did they find?
There is a link between self-reported TV viewing time and abnormal blood sugar regulation and metabolic syndrome. This correlation is strongest in those people who watch greater than 4 hours of television per day. Of critical note is that these associations persist after adjusting for moderate-to-vigorous intensity leisure time/physical activity (active couch-potato). In those individuals who watched greater than 4 hours there was an 80% increased risk of cardiovascular disease mortality.
What If I Don't Watch TV?
So you don’t watch television, how do these numbers affect you? Those individuals who spend greater than 10hrs/week sitting in automobiles (compared to less than 4 hours/week) had an 64% greater risk of cardiovascular disease. When both television and automobile time are considered, greater than 23 hrs combined (compared to less than 11 hrs/week) was associated with 84% greater risk of dying from cardiovascular disease.
Just this past week research published in Annals of Internal Medicine concluded that prolonged sedentary time was independently associated with increased cancer, diabetes, and cardiovascular disease risk independent of physical activity.
So we have seen the statistics, what can we take away from them?
It is important to recognize that meeting the minimum guidelines for physical activity does not necessarily make one physically fit. People must put emphasis on ‘not sitting’, and not just simply ‘exercising’. Taking regular breaks from sitting positions allows for improved circulation, decreased muscle strain, and improved posture. Modifying our daily routines and workstations to per
mit more time spent standing and moving is essential to improving our head.
A qualified health practitioner can give you suggestions on how to modify your lifestyle and routines to counteract the ill effects of prolonged sitting. Corrective and preventative exercise will increase the strength and resilience of your muscles, bones and joints to prevent injury and improve your health.
Here are some exercises to get you started:
3 Exercises for a Strong Back and Core
Biswas A, Oh PI, Faulkner GE, Bajaj RR, Silver MA, Mitchell MS, et al. Sedentary Time and Its Association With Risk for Disease Incidence, Mortality, and Hospitalization in Adults: A Systematic Review and Meta-analysis. Ann Intern Med. 2015;162:123-132.
Owen, N., Healy, G. N., Matthews, C. E., & Dunstan, D. W. (2010). Too Much Sitting: The Population-Health Science of Sedentary Behavior. Exercise and Sport Sciences Reviews, 38(3), 105–113. doi:10.1097/JES.0b013e3181e373a2
Ryan, T., Shaw C., Gracility of the modern Homo sapiensskeleton is the result of decreased biomechanical loadingPNAS 2015 112 (2) 372-377; published ahead of print December 22, 2014
Sitting Infographic from Austrailian Heart Foundation http://www.heartfoundation.org.au/SiteCollectionImages/Sit%20less,%20move%20more_Adults.jpg
Ware, Chris - Active Potato Illustration