Mouse study is the
first to show less strenuous alternative can benefit bone health
The Endocrine Society
A less strenuous form of exercise known as whole-body vibration
(WBV) can mimic the muscle and bone health benefits of regular exercise in
mice, according to a new study published in the Endocrine Society's
journal Endocrinology.
WBV consists of a person sitting, standing or lying on a machine
with a vibrating platform. When the machine vibrates, it transmits energy to
the body, and muscles contract and relax multiple times during each second.
Many people find it challenging to exercise regularly and that
is contributing to the obesity and diabetes epidemics. These disorders can
increase the risk of bone fractures. Physical activity can help to decrease
this risk and reduce the negative metabolic effects of each condition.
"Our study is the first to show that whole-body vibration
may be just as effective as exercise at combatting some of the negative
consequences of obesity and diabetes," said the study's first author,
Meghan E. McGee-Lawrence, Ph.D., of Augusta University in Augusta, Ga.
"While WBV did not fully address the defects in bone mass of the obese mice in our study, it did increase global bone formation, suggesting longer-term treatments could hold promise for preventing bone loss as well."
To conduct the study, researchers examined two groups of
5-week-old male mice. One group consisted of normal mice, while the other group
was genetically unresponsive to the hormone leptin, which promotes feelings of
fullness after eating. Mice from each group were assigned to sedentary, WBV or
treadmill exercise conditions.
After a week-long period to grow used to the exercise equipment,
the groups of mice began a 12-week exercise program. The mice in the WBV group
underwent 20 minutes of WBV at a frequency of 32 Hz with 0.5g acceleration each
day. Mice in the treadmill group walked for 45 minutes daily at a slight
incline. For comparison, the third group did not exercise. Mice were weighed
weekly during the study.
The genetically obese and diabetic mice showed similar metabolic
benefits from both WBV and exercising on the treadmill.
Obese mice gained less
weight after exercise or WBV than obese mice in the sedentary group, although
they remained heavier than normal mice.
Exercise and WBV also enhanced muscle
mass and insulin sensitivity in the genetically obese mice. Although there were
no significant effects in the young healthy mice, the low-intensity exercise
and WBV protocols were designed for successful completion by obese mice.
These
findings suggest that WBV may be a useful supplemental therapy to combat
metabolic dysfunction in individuals with morbid obesity.
"These results are encouraging," McGee-Lawrence said.
"However, because our study was conducted in mice, this idea needs to be
rigorously tested in humans to see if the results would be applicable to
people."