By Carol Kennedy-Armbruster, PhD/faculty, Indiana University Bloomington, SPH, and advisory board member, Wellness Council of Indiana
A recent publication by Pulsford et al (2015) in the International Journal of Epidemiology questioned the association between sitting time and all-cause mortality risk that many other sitting time studies have suggested. Other epidemiologists have touted sitting as the new smoking in terms of potential risk factors. This recent study had a dramatic headline in The Washington Post that suggested sitting for long periods doesn’t make death more imminent.
The Pulsford study was a 16-year follow-up survey utilizing self-reported sitting time data collected from 1997 to 1999. This survey data was then compared with mortality rates from 2014. The authors found that sitting time was NOT associated with all-cause mortality risk. I had a graduate student perform a literature review of recent sitting time peer-reviewed literature from 2012 to 2015. She found 17 studies that reported conflicting outcomes to this new study. What are we to believe? It’s important to consider all research and to analyze it appropriately.
My take on this issue is that we also consider “common sense” related to daily movement. We know that obesity is on the rise in our society. Our energy balance (whether that be from lack of movement, poor nutritional choices or both) appears to be tipped in the direction of causing us to “store energy” versus expend it in daily life tasks. Let’s look at the whole picture of human daily movement by analyzing a human movement paradigm based on evidence-based movement guidelines.
Human Movement Paradigm
|Exercise||American College of Sports Medicine guidelines – planned/intentional/fitness|
|Physical activity||CDC – 150 minutes/week|
|Potential emerging risk factor – sedentarism||Extended engagement in low-energy expenditure|
If you “exercise,” you get planned movement in your day. Research tells us that only 15% to 18% of the U.S. population engages regularly in “planned/intentional exercise.” If you walk and get 150 minutes of movement in a day, you get the recommended physical activity guidelines put forth by the Centers for Disease Control and Prevention (CDC). If you exercise and/or engage in low-level physical activity, you’re moving more and that’s ideal. Some studies show that if you sit too much, this risk factor of sedentarism can be a problem for you even if you exercise.
It’s important to look at one’s entire movement patterns throughout the day before determining if sedentarism is a risk factor for you or not. Basically the rule of thumb suggested in the majority of peer-reviewed studies is that moving five minutes each hour helps you think better, have better energy balance and in general makes you feel better whether you exercise or get enough daily physical activity. So, is sedentarism a risk factor or not? You know if you need to move more if you’re “storing energy” and not burning energy throughout the day. More stored energy can equate to a potential risk factor. So get up, get moving and Be WELL in whatever way works best for you. Use that stored energy versus waiting to see if it’s a risk factor for health or not.
“I move, therefore I am.”
― Haruki Murakami