Sitting Too Long is Bad for You

February 02, 2015

Sitting Too Long is Bad for You 

 Reference:   Annals of Internal Medicine Jan 2015 

 How bad?   This is a big problem. I spend all day sitting. I’m a “knowledge worker”. You know, indoor work, no heavy lifting.   Computer, desk, phone, and intellectual work.   Eight hours a day. Sound like you?  (Then I go home and slump over on the lazy boy in front of the TV - at least in winter.) 

 Ok, these guys took a serious look at the literature and found 47 studies that looked at mortality, hospitalizations, cancer, diabetes, heart disease against the variable “how long you sit”.   They did admit to quite a bit of variability in the studies and listed that as one drawback. But regardless of physical activity outside of the sedentary time, there were fairly dramatic strong associations with sedentary time and all the list above: heart disease, diabetes, cancer, hospitalizing, and just plain not living as long.  

It was across all studies.  This is what we call a "Meta-analysis", combining the data of all pertinent research to answer big, hard questions. What were the numbers?   Their data shows numbers like a hazard ratio of all-cause mortality of 1.24. That basically means you die 24% faster.   Get it? Hazard ratio for heart disease was 1.179.   That’s about 18% more heart disease. No matter how much you go to the gym, exercise outside of work or work out on weekends, you get heart disease 17.9% more just by sitting too much.    Cancer mortality? Also 17%.   Cancer incidence was 13%. Type II diabetes? 91%.   

And that may be the key link. Your diabetes risk goes up, meaning your blood sugar goes up and that leads to higher blood fats, inflammation, and glycation which are the real cause of heart disease. The authors did note that the effect was more pronounced in those who spent more time being completely sedentary, but going to the gym for 30 minutes was not protective if you then sat for 8 hours.   

There was about a 30% variability in risk between those who didn’t exercise at all with those who did, so it’s not completely accurate to portray this as a complete disqualification of exercise. But it is a risk to sit. In fact, you can put it on a par with smoking. It might be the one other most serious risk to us, besides eating diets of sugar and carbohydrates and getting fat from that. Going to the gym is very noble, it’s just not enough when you erase the benefit by sitting the rest of the day. What’s not known yet is just how much sitting can we really get away with. 

The authors suggest that we should aim for a two to three-hour reduction.   Maybe you don’t need to do it all at work. How about learning to stand more at home. Use your imagination. Create a hobby at a workbench where you can stand, instead of sit. 

 WWW. What will work for me? Ok, I’ve been talking about this forever.   I need to get over my putzing around, doing nothing. The data is there and it’s powerful. Neither you nor I can let ourselves sit every day, all day.   Find a way to re-craft your work environment so that you stand part of the day. Make a grease board on your office wall.   Put in a higher counter so that you can stand while your work. Make your phone calls standing.   Express support and admiration for those early adaptors who have already done it. Talk to your office design company!   They’ve got ideas.   But most of all, ask me what I did in my office the next time you see me. I’m determined to get over my lazy-ass attitude and get a grease board so that I can stand. I draw a lot of pictures on pads of paper. Time to do on the wall, so I’m standing.   

 Pop Quiz

  1. Sitting a lot has the ability to increase your risks for cardiovascular disease, cancer, diabetes, early mortality, more hospitalizations. T or F                        Answer:    Yup
  1. Sitting 8 hours a day may be almost as bad as smoking. T or F                      Answer:  True.
  1. Exercising has some benefit, much of it undone by 8 hours of sitting.                  Answer: Yes, it appears that the good exercisers do decrease their risk by about 30% over those who never lift a finger. That means their risk is only 70%. That’s still up.
  1. We know how much you need to stop sitting. T or F                       Answer:  Not yet.
  1. A reasonable goal would be to cut down 2-3 hours a day of sitting.                     Answer:  That’s the author’s advice.