No matter how much you exercise, sitting for extended
periods of time and for cumulative amounts of time (i.e., sitting for long periods
many times a day), may be harmful to your health. Several studies have found an association
between sitting time and things we’d rather avoid. They include 1) metabolic syndrome1
(defined as changes in 3 of the 5 following biomarkers which themselves increase
the risk of heart disease, diabetes and stroke: being overfat by waist size,
having high blood fat levels (triglycerides), high blood sugar, high blood
pressure (or being on medicine to treat either of those), and/or low HDL
cholesterol levels); 2) an increase in death
from any cause2; and 3) difficulty completing
self-care activities3, e.g., dressing, eating.
Most studies, including those whose outcomes I just
mentioned, adjusted for physical activity and found that independent of how
often a person engages in exercise, sitting for multiple 1-hour periods each
day is bad for health. Sedentary behavior - sitting around doing stuff -
is a risk factor by itself - independent of physical activity/exercise. A
person who eats a plant-based diet, does not smoke, exercises everyday... still
needs to ‘not sit’ for long periods of time.
What I mean to emphasize is that even if you go to the gym, play golf,
run, etc., an hour or more every day, the more you sit, the greater your risk
for poor health. When I suggest you sit
less and you say, “but I golfed 18 holes this morning” that is like my
suggesting you don’t smoke and you saying, “but I golfed 18 holes this morning.” Golfing does not protect you from the
consequences of sitting 6 hours a day any more than it protects you from the
consequences of smoking. Spending more
than a few hours a day in sedentary behavior puts you at risk for poor health. (I
am not sure that any scientist has quantified what amount of sedentary behavior
is actually safe, so we just have to go with ‘less is better.’)
In addition, one of the studies showed that the association
between sitting and poor health was influenced by total sitting time, AND
whether or not that total time was split up.
In other words, if two people sit for 8 hours a day, but one of them
takes short physical activity breaks every hour, the one taking the breaks will
have less disease or markers of disease (e.g., inflammation, abnormal blood
sugar) than the constant sitter.4 This is assuming that
they both exercise the same amount and are alike in other ways.
The latest study on sedentary behavior and poor health
investigated the association between sitting time and the ability to complete
Activities of Daily Living. I would like to share a few details about that
self-care study today. First the
citation and link:
In this study, Dunlop and colleagues found an association
between time spent in sedentary activity, defined as (sitting while) watching
TV, working or playing games on the computer, reading, playing cards, etc., and
difficulty completing Activities of Daily Living (ADLs).
Dunlop et al evaluated responses from a nationally
representative sample of US adults over the age of 60 who were randomly
selected to participate in one year of the National Health and Nutrition
Examination Survey, NHANES. Their study sample included more than 2000
adults who were all over age 60. Each of
the participants wore an activity monitor for 7 days. From the
information generated by the monitors, the researchers could tell when the
people were being still - as opposed to the people reporting when they were
still. (To be clear, the accelerometers were not perfect. For example, the
monitors did not detect if a person was riding a bicycle and I think the ones
used in this study could not be worn in water.) The outcome that these
researchers evaluated was ADLs. This is an important outcome because older
adults who do not have trouble with their ADLs are more likely to be able to
live independently. ADLs for this study included getting dressed, getting
in and out of bed, walking and eating.
The take home message from this study, the one that you can
apply to your life right now (even if you, like me, are under age 60) is
that in this sample of older adults, for every additional hour of sedentary
activity (sitting at the TV, computer, playing cards, reading) there was a 46%
greater chance of having difficulty with one or more of the ADLs I listed in
the above paragraph.
The researchers also studied the percent of total time in
sedentary activity per day as a predictor of ADL problems. In this case,
for every 10% increase in time spent sedentary, there was about a 70% increase
in the chance of ADL problems. I didn’t see (in the article) what the
comparison was or the absolute value, which bothers me a little. But for
simplicity, if you and I are just alike, every hour more that I sit than you
sit, my risk of having ADL trouble increases by almost 50%.
The authors of the study hope that physicians will start
asking their patients how much time they spend in sit-down activities and
encourage them to take activity breaks. One idea the authors/researchers
had is for someone to lead a physical ‘activity’ before and after a book club
or bingo meeting. I LOVE it.
1 comment:
In Todays life health is most important and this article gave me lots of tips to be healthy and fit .
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