Day 59: Volunteers keep their marbles through three months’ ’space flight’ bed rest

Another volunteer willing to spend 84 days in bed for science. Courtesy of Peter Cavanagh, University of Washington.

Tabitha Garcia had just left Texas to work the Christmas holiday at Sacks Fifth Avenue in New York. Shortly before her seasonal turn was set to expire, she was hunting around on CraigsList.org for her next opportunity, and when she saw a link asking “Are you the right one?” or some such, she clicked. 

The ad was for a University of Washington/NASA study asking volunteers to get into bed for nearly three months — 84 days — in a study of the bone loss that plagues astronauts on the International Space Station. Bone loss is the only real stumbling block left for people’s ability to live in space, now that we have spacesuits to protect people against space’s deadly vacuum and radiation. 

“Who the heck would sleep for three months? Who would do this?” Garcia remembers thinking. 

“I called anyway. Then [the program secretary] told me the stipend, and it seemed easier.”

Space station astronauts do workouts in orbit, but a new study suggests they might not be the right kind. (This is not Garcia.) Photo courtesy of Peter Cavanagh, University of Washington.

Garcia said responded to the ad in early January of 2008, then went throught three weeks of physical testing to see if she was eligible. And on Feb. 18, she got into bed, at Ohio’s Cleveland Clinic.

The study subjects lay head-down, to mimic many of the physiological adaptations astronauts experience during spaceflight, such as bodily fluid shifts toward the head. The bed rest confinement mimics the complete “unloading” of the musculoskeletal system that astronauts feel as they float through space due to the lack of gravity, which accelerates bone loss. Half the subjects are put through rigorous exercises on a treadmill, like the astronauts use. But theirs was different because they were actually pulled toward the treadmill with a powerful harness, so the workouts were higher-impact.

Garcia didn’t make the exercise group, but she said actually, the time went by fast.

“During the week, every hour is planned. You are laying there, but you have lots of activities going on,” she said, adding that baths, massages and physiological testing took most of the time. Around 6 p.m. she could talk on her cell phone or get on the Internet.  She caught up on movies. And she didn’t really mind that her study partner got all the press attention: as she polished off all the prescribed meals and her muscles lost mass, she got a little embarrassed about her appearance.

“I still did all my makeup, I did my hair, I matched all my clothing,” she said. “But it still wasn’t Sacks Fifth Avenue-worthy.”

On the weekends, things were bad, she said.

“I didn’t like the weekends at all. We didn’t get baths, and we didn’t get the massages either. That was the time when friends and family stopped by, but I had just moved from Texas.”

All the study volunteers are encouraged to take up a project during the course of the study, such as studying for exams or learning Spanish. Garcia had the idea to read a 500-page book to expand on her academic background in culinary arts. But the book was in hardcover, and heavy — and it lost its luster pretty quickly. Also, she quickly learned that she needed to write with mechanical pencils, because pens, of course, don’t work well upside down.

“I still did research on what I wanted to do,” she said: “Travel research.” She wanted to go to Columbia and Panama as soon as she finished, but that was not in the cards.

“It took me about three months to go back to normal. I finally ended up going to Panama in December.”

Study leader Peter Cavanagh, a University of Washington professor of orthopaedics and sports medicine, said the volunteers have to be raised to a standing position at the end of their terms very slowly, “because they are very likely to faint” until the heart regains its ability to push blood to the brain. Sometimes, he said, volunteers feel pain in the bottoms of their feet when they finally put them down, and have trouble navigating corners while walking.

“They feel sort of generally weak,” Cavanagh said. “We put them through two weeks of rehab, and we buy them a membership at the health club for another month.”

Garcia said one of the study participants actually fell when the doctors put him upright, but “not me. I didn’t fall,” she said – and that’s apparently a point of pride.

Cavanagh said the results from the first half of the study are “extremely promising.” Of the five study subjects so far who have been assigned to the exercise group, bone loss in four of them has been prevented in important skeletal regions by the treadmill exercise countermeasure, while the six non-exercising control subject participants all lost bone mass.

“We have found that we can, on average, prevent bone loss in an important region of the hip with this intervention,” Cavanagh said. “No bed rest study ever before has accomplished this.”

Cavanagh said the study results will impact bone health in space by improving exercise prescriptions for astronauts on future space missions. Here on Earth, the work could help scientists understand how individualized exercise programs affect age- and gender-related osteoporosis.

As for the volunteers, they do okay.

“One of my most satisfying moments,” Cavanagh said, “is handing them a $12,000 check at the end.”

The end came for Garcia on May 12 of last year, and she says it was a great experience that she’d repeat if she could.

“It’s not every day you can do this. Even when I was a little girl, I wanted to do something for NASA,” she said. 

“Be careful what you wish for.”

See another version of this story I wrote for Universe Today!