Planning A Mars Trip? Start With A Workout Regimen

Wednesday, October 24th, 2012

by AJ Plunkett

Turns out that eating right and proper exercise are good for you. (Don’t you hate it when the doctor is right?) And if that’s not reason enough to eat your veggies, staying fit might be necessary to survive a two-to-three-year trip to Mars and back.

Researchers have long known that astronauts lose bone density during extended missions in the microgravity of space — an average of 1 to 1.5 percent in a single month. By comparison, seniors lose about the same amount of bone mass in an entire year.

So, being in space can make you feel old. Literally.

After extended missions, astronauts begin to experience fatigue and problems with physical stability, their sleep cycle is disrupted, their muscles and immune system are weaker, and their blood circulation is wonky. That’s on top of the bone density loss, which can make astronauts more susceptible to injury.

(Makes you wonder why people volunteer for this, doesn’t it? We suspect it’s their incessant curiosity.)

Photo: Enrico Agnosti / Shutterstock.com

Another thing that’s different: while everyone gets shorter with age, in space, you get taller. The discs between the vertebrae in your spine compress every day because of gravity and don’t entirely recover overnight — eventually you lose height. In space, the discs actually expand, making you taller. (The downside is that your back might hurt.)

While most of the physical side effects of being in space are due to microgravity, exposure to higher levels of space radiation can also impact an astronaut’s health.

Extra shielding in the International Space Station has shown to help protect astronauts from the radiation. But what about gravity? And what does it mean for extended space travel?

While gravity on Mars may only be 38 percent of what it is on Earth, it still would cause problems for explorers with weakened muscles and more brittle bones after a long trip in no gravity at all.

That’s why researchers are excited about data that shows astronauts who switched to more intensive, resistance workouts “came home with more lean muscle and less fat, and kept more of their whole body and regional bone mineral density,” according to NASA information.

The study, published in the September 2012 issue of Journal of Bone and Mineral Research, compared information gathered on astronauts before and after a new Advanced Resistive Exercise Device (ARED) was installed on the Space Station in 2008.

The ARED doubled the maximum simulated weight that the astronauts could “lift” in microgravity. The harder workout, combined with a diet “sufficient in calories and vitamin D, among other nutrients,” is believed to have produced the healthier results.

“After 51 years of human spaceflight, these data mark the first significant progress in protecting bone through diet and exercise,” said Dr. Scott M. Smith in a NASA release. Smith is the nutritionist at NASA’s Johnson Space Center in Houston, and lead author of the study.

“These data will be critical in enabling us to send humans, once again, to destinations beyond low Earth orbit,” Smith expained.

Of course, much more research into all kinds of physical side effects needs to be done before that can happen. Experiments on the Space Station now include how diets with different ratios of animal protein and potassium affect bone health, and the benefits of lowering sodium intake.

Now, what was the doctor saying about less salt in the diet?

AJ Plunkett is a freelance writer in Virginia with experience in covering defense and aerospace industries, as well as health care issues. AJ blogs via Contently.com.