Don't Just Sit There, Do Something! Part 5

A day late & a dollar short.  It's been rumored that I'll be late to my own funeral.  So it's no surprise that thanks to USA Today, I stumbled upon yet another study linking inactivity to mortality - a year after it was first published!  Better late than never!

So what did I miss?  Well, this was a 14 year observational study sponsored by the American Cancer Society involving 53,440 men (avg 63.6yo) and 69,776 women (avg 61.9yo) who were all disease-free at enrollment. These individuals were part of ACS' Cancer Prevention Study II and specifically selected because they did not have a personal history of cancer, heart attack, stroke, or emphysema/other lung disease.  Others from the larger cohort were excluded due to missing information.

After breaking down the individuals into tertiles based upon time spent sitting, the authors noted that those who spent 6 or more hrs/d sitting outside of work had a greater all-cause mortality than those who spent less than 3hrs/d sitting outside of work.  Physically activity as measured & calculated by metabolic equivalent (MET)-hours/wk was also inversely associated with all-cause mortality at a cut off of 24.5MET-hours/wk.  The association remained after adjusting for the usual suspects such as smoking & body mass index. 

So what are we to make of this study, especially in light of my recent diatribes about research & statistics?  Because it's observational, no proof of cause & effect can be made.  Instead, this study can only be used to develop (and support) a hypothesis.  But as I also mentioned, the practice of evidence-based medicine means making the most of what we currently have available to us.  In the particular scenario of time spent sitting each day, less is more.  Consider the alternative (or at least the consequence).  So don't just sit there, do something!  And if you don't believe this study, check out Part 4!