How do you test the effects of weightlessness in space without risking lives and a lot of money?

Use a bed. People in bed with their heads 6° below the horizontal for long periods causes their bodies to react in similar ways to being weightless and so bedrest studies are being used to answer questions on how our bodies adapt to living in space and and even how our bodies adapt to growing old. Like Tang and pens that write upside down, findings from bedrest studies may apply directly to people on Earth.

In an ESA project, 12 volunteers are about to spend 21 days in bed, lying with their heads tilted below the horizontal, and they will not be allowed to get up, not even once, for a breath of fresh air, a change of scenery, a shower or to use the toilet. Then they get to do it again a few months later.

 As we age, our bodies lose bone density and muscle strength. Astronauts in space suffer similar changes but at a much faster rate than on Earth. Finding ways to combat this process is important to space agencies but also to hospital patients and everyone who plans on growing old.

In the study, the 12 volunteers are divided into three groups to test a set of countermeasures to muscle and bone loss. The control group will spend 21 days in bed without any countermeasures, while a second group follows a schedule using resistive and vibrating exercise machines. The last group will use the exercise machines and eat nutritional supplements of whey protein – a common supplement used by bodybuilders to train their muscles.

Checking the bed angle during the 2005 bedrest study. Credits: CNES–S. Levin, 2005

Although the properties of whey protein are well known to bodybuilders, will the protein help to maintain muscle strength without hours spent in the gym? The healthy volunteers will participate in all the regimes one after the other over the course of the entire experiment of more than a year. 

After the first 21-day session, which started yesterday, they will return to the clinic in Toulouse, France, for another session and once more in 2013 for a final session. The volunteers will have four months between each bedrest session to recuperate, get some real rest and appreciate getting out of bed in the morning.