Although there are no sure-fire recipes for good health,
the mixture of healthy eating and regular exercise comes awfully close. Most of
The Nutrition Source is dedicated to singing the praises of a good diet. This
is where physical activity gets its due.
Regular exercise or physical activity helps many of the
body’s systems function better, keeps heart disease, diabetes, and a host of
other diseases at bay, and is a key ingredient for losing weight. According to
the 2008 Physical Activity Guidelines for Americans, (1) being physically
active on a regular basis
Improves your chances of living longer and living
healthier
Helps protect you from developing heart disease and
stroke or its precursors, high blood pressure and undesirable blood lipid
patterns
Helps protect you from developing certain cancers,
including colon and breast cancer, and possibly lung and endometrial (uterine
lining) cancer
Helps prevent type 2 diabetes (what was once called
adult-onset diabetes) and metabolic syndrome (a constellation of risk factors
that increases the chances of developing heart disease and diabetes; read more
about simple steps to prevent diabetes)
Helps prevent the insidious loss of bone known as
osteoporosis
Reduces the risk of falling and improves cognitive
function among older adults
Relieves symptoms of depression and anxiety and improves
mood
Prevents weight gain, promotes weight loss (when combined
with a lower-calorie diet), and helps keep weight off after weight loss
Improves heart-lung and muscle fitness
Improves sleep
The Cost of Inactivity
If exercise and regular physical activity benefit the
body, a sedentary lifestyle does the opposite, increasing the chances of
becoming overweight and developing a number of chronic diseases. Despite all
the good things going for it, only about 30 percent of adult Americans report
they get regular physical activity during their leisure time—and about 40
percent of Americans say they get no leisure-time physical activity at all.
(25) Studies that measure people’s physical
activity using special motion sensors (called accelerometers) suggest that
self-reports of physical activity probably are over-estimated. (26). According
to analyses by a team from the Centers for Disease Control (CDC) and
Prevention, inactivity was associated with more than 9 million cases of
cardiovascular disease in 2001, at an estimated direct medical cost of nearly
$24 billion. (2) Another CDC analysis suggests that because individuals who are
physically active have significantly lower annual direct medical costs than
those who are inactive, getting people to become more active could cut yearly
medical costs in the U.S. by more than $70 billion. (3)
Being a “couch potato” may be harmful even for people who
get regular exercise. (4) The Nurses’ Health Study, for example, is one of
many, many studies to find a strong link between television watching and
obesity. (5) Researchers followed more than 50,000 middle-aged women for six
years, surveying their diet and activity habits. They found that for every two
hours the women spent watching television each day, they had a 23 percent
higher risk of becoming obese and 14 percent higher risk of developing
diabetes. Interestingly, it didn’t matter if the women were avid exercisers:
The more television they watched, the more likely they were to gain weight or
develop diabetes, regardless of how much leisure-time activity and walking they
did. Long hours of sitting at work also increased the risk of obesity and
diabetes.
More recently, studies have found that people who spend
more time each day watching television, sitting, or riding in cars have a greater chance of dying early than
people who spend less time on their duffs. (6-8) Researchers speculate that
sitting for hours on end may change peoples’ metabolism in ways that promote
obesity, heart disease, diabetes, and other chronic conditions. (4, 7) It is
also possible that sitting is a marker for a broader sedentary lifestyle.
In sum, a morning jog or brisk lunchtime walk brings many
health benefits—but these may not entirely make up for a day spent in front of
the computer or an evening in front of the television set. So as you plan your
daily activity routine, remember that cutting down on “sit time” may be just as
important as increasing “fit time.”
