Briefly standing, or being active, reduces blood sugar across the day

LONDON: For obese people who sit for most of
the day, replacing some sitting time with
standing, slow walking or slow cycling reduces
average blood sugar across the day and into the
night, a small study finds.
“Anything you can do to bring down glucose
readings throughout the day is a good thing,”
said senior author Glenn Gaesser of the School
of Nutrition and Health Promotion at Arizona
State University in Phoenix.
“We chose a typical workday because a large
number of Americans spend a lot of time sitting
at an office desk, and a number of (studies)
indicate sitting is a health hazard, so we
reckoned that trying to alleviate that by either
standing or walking or cycling would help,”
Gaesser told Reuters Health.
The researchers studied nine overweight or
obese adults who wore continuous blood sugar
monitors and blood pressure monitors during
their regular, mostly-sitting eight-hour workday.
One week later, participants gradually replaced
some of that sitting time with standing, in
intervals of 10 to 30 minutes for a total of two
and half hours per day.
The following week, the same amount of sitting
time was replaced with walking at a treadmill
desk at a pace of one mile per hour. In the
fourth week, the intervals were spent cycling on
a stationary bike retrofitted to a workstation,
also at an extremely slow pace with low energy
expenditure.
Average 24-hour glucose was lower for standing
and walking than for sitting, and was lowest on
the cycling days, the researchers report in
Medicine and Science in Sports and Exercise.
There was a similar pattern during the hours
right after eating and even during overnight
hours, with people having sustained lower blood
sugar overnight after days they had cycled.
This is “not wholly surprising," because other
research in the last few years has shown that
breaking up prolonged sitting has benefits on
glucose over the course of a day, said Dr. Daniel
Bailey of the University of Bedforshire in the
U.K., who was not part of the study.
It’s uncertain if the difference in blood sugar
would have clinical significance or reduce
metabolic risk, but that would be more likely for
walking and cycling than for standing, which
only resulted in a small reduction, Bailey told
Reuters Health by email.
“Studies with larger groups would be needed
before we could say these findings would apply
to overweight people in general,” he said. But
it’s likely that overweight or prediabetic people
may benefit more from breaking up periods of
sitting than healthy-weight people, he said.
“We found that the overall reduction in blood
sugar throughout the 24-hour day was typically 5
percent to 12 percent, with the greatest effect
being in cycling,” Gaesser said.
After a meal of carbohydrates, most blood sugar
is disposed of in skeletal muscle, and muscle
contractions increase insulin activity and
glucose uptake, which helps to lower blood
sugar, he said.
“For low-level activity throughout the workday,
the effect lasts well after the last exercise bout
at 4:30 or 5:00 in the afternoon,” continuing into
sleep, he said.
Breaks in sedentary time are good, even if you
don’t have access to a walking or cycling
workstation, Gaesser said.