Preventive Medicine Column

Dr. David L. Katz

Less sitting could extend our lifespan- and more importantly, our healthspan.

Getting to sedentariness by the seat of our pants increases risk for chronic disease, and shortens our lives.  Specifically, the evidence on this front is that sitting for 8 hours a day is associated with an increase in all-cause mortality risk of 15% at any given age, and sitting for 11 hours a day is associated with a 40% increase.

Merely getting off the seats of our pants more often confers the promise of the opposing benefits: less chronic disease, longer life expectancy.  The study just published in the British Medical Journal suggests a potential gain in life expectancy of 2 years on average from reducing total daily sitting to less than 3 hours.

The larger context here is largely a matter of common knowledge at this point.  Exercise is good for us- and we get too little of it.  While the particular benefits of exercise, in its various forms, to weight loss is fodder for frequent, and in my opinion largely futile, debate- the value of exercise to health is all but indisputable.  Physical activity is the vital, conditioning work of the human animal.  We were meant for it, and we need it.

But alas, we are getting less and less.  Just this week comes news that more and more schools- in the face of epidemic childhood obesity and diabetes- are cutting physical education, rather than expanding it.  And this despite the fact that good physical activity programming during the school day preserves or enhances academic performance, rather than interfering with it- and confers additional benefits into the bargain.  In the case of our own research, findings suggest that if routine ‘recess’ is used to treat rambunctiousness, less Ritalin is needed to treat ADHD!

Exercise has been squeezed out of the average day for adults and kids alike.  And in the absence of dedicated wellness programming, there is less and less on-the-job physical activity as well.

At one point, this might have left us with a square peg/round hole dilemma: do without exercise, or free up a big block of time every day to make room for it.   The trends in schools, work places, and our society at large suggest that this dilemma gets the better of us.

Fortunately, we have long since come to recognize that just about any way of fitting in exercise is a good way.  It needn’t be in one long bout, and we needn’t all make the Olympic team.  Brief bursts of exercise that add up to a reasonable dose (20-30 minutes) over the course of the day will do just fine; as will moderate intensity.

The recent studies expand the realm of relevant physical activity options.  Suddenly, just standing up qualifies.

If you are stiff, or sore, after hours at a desk- it may be time to get up, walk around, stretch out a bit.  If you are feeling sluggish, feel your productivity declining, need something to boost your energy- a walk might be a far better solution than an energy drink.

And we can do more than just stand up, even if we only have a few minutes free at a time.  Colleagues and I have developed a free physical activity program for kids in school (or at home), and another for adults at work, that allow for intermittent, brief bursts of high quality physical activity throughout the day.  There are options for converting work at a desk from a sitting to a walking activity for those so inclined.  And there are ways of adding physical activity that are as much about having fun as they are about finding health.

If just standing more and sitting less can add years to life and life to years, then we owe a lot of ill health to the seats of our pants.   The solution is for us each to incorporate strategies into our daily routines that allow us to get up and move about- at least a little, at least intermittently.  It’s not aviation science, and no complex instrumentation should be required.  I think, in fact, we should all be able to get there- by the seat of our pants.




Dr. David L. Katz;