People + Process = Performance

Sitting Isn’t Really “Sitting Disease”??

A new study is challenging the current trend in thinking that prolong sitting increases the risk of an early death.  The study, from the University of Exeter and University College of London, goes against previous studies that state the act of sitting itself is harmful to one’s health even if people are regularly active or exercise.  It also disputes widespread recommendations (USA’s CDC and UK’s NHS) that remaining seated is unhealthy, regardless of the amount of exercise one does.

The study was published in the International Journal of Epidemiology.  The abstract of the study is as follows: (quoted verbatim)

Background: Sitting behaviours have been linked with increased risk of all-cause mortality independent of moderate to vigorous physical activity (MVPA). Previous studies have tended to examine single indicators of sitting or all sitting behaviours combined. This study aims to enhance the evidence base by examining the type-specific prospective associations of four different sitting behaviours as well as total sitting with the risk of all-cause mortality.

Methods: Participants (3720 men and 1412 women) from the Whitehall II cohort study who were free from cardiovascular disease provided information on weekly sitting time (at work, during leisure time, while watching TV, during leisure time excluding TV, and at work and during leisure time combined) and covariates in 1997–99. Cox proportional hazards models were used to investigate prospective associations between sitting time (h/week) and mortality risk. Follow-up was from date of measurement until (the earliest of) death, date of censor or July 31 2014.

Results: Over 81 373 person-years of follow-up (mean follow-up time 15.7 ± 2.2 years) a total of 450 deaths were recorded. No associations were observed between any of the five sitting indicators and mortality risk, either in unadjusted models or models adjusted for covariates including MVPA.

Conclusions: Sitting time was not associated with all-cause mortality risk. The results of this study suggest that policy makers and clinicians should be cautious about placing emphasis on sitting behaviour as a risk factor for mortality that is distinct from the effect of physical activity

 

As you can see, during the 16 years in which this study’s participants were followed, none of the five sitting measures influenced their mortality risk. 

I found an interesting quote from one of the authors in the study’s release:

Study author Melvyn Hillsdon, PhD, from the Sport and Health Sciences department at University of Exeter states that, “Our study overturns current thinking on the health risks of sitting and indicates that the problem lies in the absence of movement rather than the time spent sitting itself. Any stationary posture where energy expenditure is low may be detrimental to health, be it sitting or standing.”

“The results cast doubt on the benefits of sit-stand work stations, which employers are increasingly providing to promote healthy working environments.”

So, what is a person to conclude about prolonged sitting?  Is it a “disease” that will lessen one’s lifespan or is it just another lifestyle factor that in and of itself is no more risky than anything else?  There’s no doubt the studies are at odds with each other and that more studies with large populations or a long period of time are needed to settle this conclusively, if that is possible.  My recommendation was and still is this: “MOVE!”  Movement at some point during the day, every day is key.