No Amount of Exercise will Undo the Harm of Sitting all Day
We sit a lot. We drive to work, sit at our desks, and watch TV after dinner. Most of us spend more than half of our day sitting and this sitting is making us sick.
The risks of sitting
The effects of sitting are scary. We’ve found that sitting leads to a huge jump in risk of colon, endometrial, and lung cancer. For each extra two hours we spend sitting each day, we face a statistically significant 8% increase in colon cancer risk and 10% increase in endometrial cancer risk. In addition, those of us with jobs that require us to sit, face twice the risk of cardiovascular disease. It is time, as Dr. Hamilton of the University of Missouri suggests, we consider sitting all day to be “a serious health hazard”.
We’re not made to sit for this long
When we sit, we burn roughly one calorie a minute. This means we face a greater possibility of being overweight which leads to a whole host of chronic diseases.
When we sit, our muscles don’t do any work. “Skeletal muscles have an electrical activity in them when they’re working which is like the light switch that turns on all these healthy things in the muscles,” explains Dr. Hamilton. When we sit, all this activity shuts down.
Inflammation and gene suppression
When we don’t move, a gene that reduces inflammation and aids in blood clotting is suppressed. As Runner’s World magazine put it, “Sitting is the new smoking. Even for runners.”
Exercise doesn’t help
The scariest part of this research is that exercise doesn’t seem to help. Ever since we were kids, we’ve been told that we need to have 30 minutes of exercise per day.
However, what we do for the 15.5 hours we don’t spend sleeping or exercising is just as important in staying healthy. The study found that people who were physically active for 30 minutes in their otherwise sedentary day were still larger, had higher systolic blood pressure, and higher levels of cholesterol.
Another study found that lipoprotein lipase (LPL) activity drops significantly when we stop moving . LPL is what Dr. Hamilton calls “a vacuum cleaner for fats in the blood stream”. When researchers made rats sit for 24 hours they found that the rats’ LPL levels dropped by 95%. Without the vacuum cleaner working, the rats lost 75% of their ability to get rid of noxious fats from the bloodstream. They also had a significant decrease in “good” cholesterol (HDL cholesterol). Even when the rats were made to exercise intensely for hours, their LPL activity didn’t increase to anywhere close the original levels. Exercise barely helps.
Sitting is the new smoking, even for those who exercise.
Most of us have to sit for most of the day. We can’t help but sit when we drive or work at the computer, and we sit when eating dinner with friends and family.
- Take small breaks. Stand up and walk around for two minutes after a half hour of sitting.
- If you have a sedentary computer job, make it a habit to stand up and stretch while taking phone calls. Or better yet, use a hands free or headset and walk around. I know a colleague who has all meetings, in person or by phone, while going outside for a walk.
- Create a sit-stand workstation by lifting your monitor and keyboard to accommodate you standing for ½ an hour or longer at a time during the day.
- Use an exercise ball to sit on for part of the day. It is hard to be perfectly still when sitting on a ball. You have to keep using your postural muscles to balance yourself.
- Walk around the block during your coffee and lunch breaks. The fresh air is good for you too.
- Opt for the stairs, instead of the elevator.
My Bottom Line
We need to rethink the concept that being active for 30 minutes a day is enough to be healthy. What we need is to do more light activity – walking, standing, stretching – activities that we don’t even think of as exercise. Let’s try and move around more during our day – we’ll be healthier, and feel healthier too.