NASA-Funded Study Finds Exercise Could Help Women on Bed Rest

Nov. 15, 2007

Melissa Mathews/Beth Dickey
Headquarters, Washington
202-358-1272/2087
melissa.mathews-1@xxxxxxxx, beth.dickey-1@xxxxxxxx

Marc Ransford
Ball State University, Muncie, Ind.
765-285-1570
00meransford@xxxxxxx

RELEASE: 07-253

NASA-FUNDED STUDY FINDS EXERCISE COULD HELP WOMEN ON BED REST

WASHINGTON - Short but intense sessions of exercise may help women on
bed rest stay strong and recuperate more quickly, according to a
NASA-funded study by researchers at Ball State University, Muncie,
Ind. The findings of the first comprehensive bed rest study focusing
exclusively on women will help NASA develop more effective
countermeasures to mitigate strength and muscle loss in female
astronauts on long-duration missions to the International Space
Station and, perhaps, someday to Mars.

It also may have implications for women on Earth confined to bed rest
because of illness, injury or pregnancy.

"With NASA astronaut Peggy Whitson commanding the International Space
Station now and astronaut Pam Melroy commanding the last space
shuttle mission, we're reminded daily that women make up an important
segment of our astronaut corps and are taking on more and more
leadership roles," said Carl Walz, a former long-duration astronaut
and head of NASA's advanced capabilities division in the agency's
Exploration Systems Mission Directorate, Washington. "It's important
that we look at how space travel -- microgravity, radiation, and
other factors -- affects women and men differently."

Ball State's Human Performance Lab has been working with NASA for
more
than a decade to examine the impact spaceflight has on humans,
according to Scott Trappe, the lab's director. He co-authored the
study with fellow lab researcher Todd Trappe, his brother.

"Until we completed this study, we had no solid research on how women
would adapt to long durations in space," Trappe said. "This
information should have a dramatic impact for NASA in the coming
years."

Conducted in Toulouse, France, the study was sponsored jointly by the
European Space Agency, the Canadian Space Agency, the French space
agency CNES, and NASA. Results were published recently in the Journal
of Applied Physiology and Acta Physiologica.

The study examined 24 female participants to determine whether
specific exercise regimens or nutritional supplements could prevent
the loss of lower body muscle mass and strength. The women spent 60
days on bed rest. They lay with their heads pointing downward at a
6-degree angle, which researchers believe most accurately simulates
the weightless conditions of space. One group was put on an exercise
regimen. A second group was put on a high-protein diet rich with
leucine, an amino acid. The control group did not take part in any
exercise or dietary protocols.

"When we looked at these women after two months, the difference in
the
physical condition among the three groups was undeniable," Trappe
said. "The women who did not exercise lost nearly half their strength
in some cases. What's more, the group who ate a high-protein diet but
did not exercise lost even more muscle mass than the control group."

The exercise regimen included a 40 to 50 minute aerobic workout two
or
three times a week and 20-minute strength training sessions two or
three days a week. While lying on their backs, the women did multiple
sets of thigh and calf exercises using a flywheel device similar to a
typical leg press machine at a gym. They also worked out on a
vertical treadmill.

"The message for women and their doctors is that it really took very
little exercise to make an impact," said Trappe. "The total time
spent exercising was less than two percent of the time they spent in
bed during the entire 60-day period. In the end, a little bit of
intense exercise goes a long way."

Using a magnetic resonance imaging device, or MRI, researchers
measured muscle mass in all of the study subjects after the 60-day
period. They found that women in the control group lost 21 percent of
the muscle mass in their quadriceps, and the nutrition group lost
more than 24 percent, but the exercise group lost none. Results were
similar for MRI scans of the calf muscle.

The loss of muscle strength was even more significant. Researchers
tested strength using the flywheel device. Women who did not exercise
during the study lost as much as 33 percent of their strength in
squat exercises and 46 percent in calf press exercises. But the women
who exercised maintained their strength.

NASA's Human Research Program is working to understand the health
effects of spaceflight on astronauts in preparation for long-duration
missions. "It could take six months to reach the surface of Mars, and
we have to make sure our astronauts are healthy when they get there,"
Walz said.

For more on NASA's space exploration plans, visit:

www.nasa.gov/exploration


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