Scientists Get Closer to Figuring Out How Exercise Works
But We’ll Have to Wait On the Workout Pill
by Jovaughn Lane, age 14
 If
you had the decision to jog a few miles or take a pill that could
possibly have the same health effect, what would you choose? Most people
would take effortless fitness over sweating bullets. According to a new
study by a team at Scripps Research Institute in Jupiter, Florida,
scientists may have stumbled onto a compound that simulates the effects
of exercise.
The study reported a compound that increased the
activation of a protein called REV-ERB, which is known to partially
control animals’ circadian rhythms and internal biological clocks.
The
study was tested on mice. The mice that were injected with the compound
lost weight even on a very high fat diet, while also improving their
cholesterol profiles. Unexpectedly, the mice that were injected also
started to use more oxygen throughout the day, expending five percent
more energy than the untreated mice. In most cases, they were more
physically lazy and inactive prior to the injection. The drug seemed to
provide them with a workout without the effort.
Interested, the
Scripps scientists along with researchers from Pasteur Institute in
France and other institutions set out to find out what their compound
might be doing inside muscles to provide this simulated workout. They
knew the drug increased the potency of REV-ERB but did not know what
REV-ERB actually does in muscles.
So in a separate part of the
experiment, scientists used genetically engineered mice that did not
generate very much REV-ERB. They noticed these mice were weak and
inefficient specimens, and produced far fewer mitochondria than the
normal mice. Mitochondria are the cellular structures that produce
energy using up oxygen. But when scientists added the
REV-ERB-stimulating compound, they found the genetically modified mice
began to make more, and strengthen existing, mitochondria. This is the
same effect that exercise has on mitochondria. Under regular conditions,
the mitochondria in muscle cells increase in number and strength during
exercise. These weak, slow, genetically modified mice had a 60% reduced
oxygen capacity compared to regular mice. This is the same effect that
exercise has on mitochondria.
Finally, scientists injected
sedentary mice, increasing their production of REV-ERB far more than
regular mice would be expected to have. When they tested these mice on
little treadmills, they ran an exceptionally longer time and distance
than untreated mice, even though they had not been training.
Scientists
are unsure of the potential harmful side effects the compound could
have. Although taking a pill may be the easiest thing, no drug can take
place of all the good things exercise can do for us, such as, a
psychological feeling that we are improving our own lives. It is
doubtful that exercise will be fully reduced to tablet form in the near
future.
[Source: New York Times]
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