New research supports the idea that spending more time
standing during waking hours can help to counteract some of the negative
consequences of sedentary lifestyles.
Compared
with sitting or lying down for the same amount of time, standing uses more
energy. This could help to burn calories that would
otherwise end up in fat storage.
These
are among the findings and conclusions of a recent PLOS One study from the University of Granada (UGR), in Spain.
Many
scientists believe that lying, sitting, and standing use up different amounts
of energy.
However,
until the recent study, no one had quantified the energy differences between
the three behaviors.
In the new
investigation, corresponding study author Francisco J. Amaro-Gahete and
colleagues calculated that the body expends 45 more kilocalories per 6-hour
period when standing, compared with lying down or sitting.
The
team found little significant difference in energy expenditure between lying
and sitting.
Health hazards of prolonged sitting
"We
Spaniards spend between 8 and 10 hours sitting or lying down each day, not
counting the hours we are asleep," says Amaro-Gahete, who is studying for
a Ph.D. in biomedicine at UGR.
Prolonged
sitting is also common in the United States. A 2018 study by
the Centers for Disease Control and Prevention (CDC) found that around 25% of
people in the U.S. spend more than 8 hours per day sitting.
The
new findings follow numerous studies on the health hazards of prolonged sitting
and the benefits of reducing it.
A study that
spanned 45 years concluded that being physically inactive is second only
to smoking as a risk factor for early death.
Even
short bouts of activity can reduce the health risks of a sedentary lifestyle,
according to other research that reviewed dozens of
studies.
Another study of
adults in middle age and older also found that prolonged sitting can harm the
brain. Even high levels of physical activity appear to make no difference.
"Therefore,
if we take steps to combat a sedentary lifestyle by making small lifestyle
changes," Amaro-Gahete suggests, "such as spending more time
standing, this could reduce the risk of developing diseases such as obesity or type 2 diabetes."
Savers vs. spenders of energy
For
the new study, the researchers measured energy expended during time spent
sitting, lying, and standing in 55 healthy adults. The average age of the
volunteers was 21.7 and 69% of them were female.
The
team used a noninvasive method called indirect
calorimetry to measure energy expenditure in each of the three
positions: sitting, standing, and lying down.
Indirect
calorimetry is one of the most accurate and sensitive ways of measuring a
person's energy use noninvasively.
The method
measures energy expenditure from the amount of oxygen that the body uses and
the amount of carbon dioxide that it releases.
As
well as demonstrating that, in general, standing uses more energy than sitting
and lying, the study found that the participants fell into two types of energy
users: savers and spenders.
It
seems that spenders use more energy when they switch from lying or sitting to
standing.
"Savers
consume very little energy in their activities and, therefore, the difference
between sitting [and] lying or standing is practically nil for them,"
Amaro-Gahete explains.
Spenders,
on the other hand, burn around 10% more energy when they switch to standing
from lying or sitting, he adds.
Muscle mass could be a factor
Researchers
are still trying to figure out why some people are energy savers and others are
energy spenders.
The answer
to that question could help explain why some people lose weight with great
difficulty while others do so with ease.
In
conclusion, the researchers suggest that people with sedentary occupations,
such as office workers, should spend more time standing up.
While
the findings appear to support the use of desks that people can adjust to allow
them to work standing up, there are other ways to counteract the effects of
prolonged sitting.
The
important thing is to change position, says senior study author Jonatan R.
Ruiz, Ph.D., an associate professor in the Faculty of Sport Sciences at UGR.
"If a person were to
get up, take 10 steps, and sit down again, it appears that the effects of a
sedentary lifestyle would be greatly reduced."
Jonatan R.
Ruiz, Ph.D
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