“Sitting is the new smoking”. This is the new mantra in
cardiology and global population health. Sitting, or a sedentary lifestyle, has
long been known as a risk factor for the development of heart disease.
Excessive sitting is also associated with a higher mortality rate. Is sitting really
as bad as smoking for your health? Why is sitting so detrimental? What
strategies can combat a sedentary life?
A sedentary lifestyle is a global health hazard. In a recent study looking at adults in 54
countries (representing 25% of the world’s population), more than 61% of people
sat for more than 3 hours per day. It was found that sitting for > 3 hours
per day could account for 433,000 deaths per year globally. Why is sitting so bad? Sitting reduces
glucose uptake and leads to diabetes. When sitting, triglycerides are not used
or broken down. This increases the level of triglycerides in the blood, which subsequently
lowers the good cholesterol (HDL). The combination of high triglycerides, low
HDL and diabetes all lead to heart disease.
Sitting also results in obesity and fat deposition in the heart. In addition, recent research showed that
patients who sat for more than 10 hours per day had above average levels of
troponin in their blood. Troponin is an enzyme that is released when the heart
muscle is injured. High levels of troponin are released during a heart
attack. It was found that sedentary
individuals have chronically high levels of troponin (although at much lower
levels than heart attack patients). Chronically high troponins indicate that
the heart muscle has ongoing damage occurring.
To combat this ongoing damage, a change from a sedentary lifestyle
to even a mildly active lifestyle can yield great benefits. Any physical activity
is better than no physical activity. For instance, replacing sitting with
standing for 2 hours per day is associated with a 10% lower chance of death. There
appears to be a benefit even if the recommended amount of exercise (150 minutes
of moderate exercise per week or 75 minutes of vigorous exercise per week) is
not met. In those who only exercised to about two thirds of the weekly
recommended volume, there was a lower mortality rate than those who were
sedentary. Increasing the amount of
exercise results in further reductions in cardiac disease and mortality.
Walking is a great way to get the recommended exercise. It
doesn’t require any training or equipment; it’s cheap and easy to do. Since walking
alone can be boring, many people join a walking group or walk with a friend.
However, what if the friend is ill and can’t walk? What if they are away or
have other engagements? Wouldn’t it be
great to have a walking partner available at all times? A partner that has
walking in its DNA? A partner that would never refuse to go out for a walk, no
matter the weather? Look no further than the family dog. It has been shown that
dog owners who walk their dogs are more likely to achieve recommended exercise goals,
have lower cholesterol levels, lower blood pressure and less obesity. In
addition, dogs offer social support by providing companionship and acting as a
vehicle for increased interaction with other people while out walking. Can owning a dog prolong life? In a recent study of 3.4 million Swedes, researchers
compared hospital records with dog ownership registers. They showed that owning
a dog reduced the risk of death by 33% and reduced the risk of a heart attack
by 10%. Perhaps this effect may be
because more active people choose to own dogs or perhaps dogs alter the balance
of the household and force people to be active at least a couple of times per
day.
The most troubling aspect of the research on sedentary
lifestyles is that sitting for prolonged periods (more than 7 hours per day)
can still increase the risk for death even if the recommended amount of
exercise is met. This means that going to the gym after work won’t offset the
potential damage done by sitting for hours in an office all day. Therefore it
is important to consider physical activity across the entire spectrum, by
incorporating a weekly exercise regimen and to use light intensity physical
activity to replace sitting during the daily routine.
So, to live a longer
and healthier life, first get off of the couch. Next, in addition to starting a
weekly exercise program, start altering your daily habits to incorporate more
exercise and less sitting. Take the stairs at work. Park at the end of the
parking lot and walk further to the office. Instead of sitting at your desk,
try a standup desk, or a desk that has a treadmill underneath it. With more
activity and less sitting, you might find yourself more productive. Hold
meetings in rooms without chairs. By standing and talking meetings may be
quicker and more productive. Buy a smart watch that gives you an alert when you
have been sitting too long. And, of course, take your furry friend out for a
nice long walk when she scratches at the door.
