What's The Link Between Astronauts and Osteoporosis?, International Osteoporosis Foundation
"Though most people may not think of it, bedridden patients and astronauts share something in common: progressive bone loss. Immobile patients lose bone density because they don't exercise muscles that would otherwise build skeletal strength through motion. Astronauts also face long periods of immobility, in addition to zero gravity, which negatively affects bone cell function."
NASA's bed rest subjects have lot of time to blog, Knight Ridder
"On a Monday morning nothing sounds better than lying in bed just a little longer, but 12 weeks longer? The folks at Stardust Holiday (http://stardustholiday.blogspot.com) are chronicling their time as part of a NASA bed rest study. Participants (who, yes, are being compensated) are spending 84 days in the Cleveland Clinic in bed. As if that's not enough, they're lying at 6 degrees head down. Half of them are in a control group, with no exercise, and the other half gets some exercise."
Despite the importance of this research - and the personal sacrifices made by the people who volunteer three emonths of their life - NASA PAO simply ignores the topic - and the people involved. Now another volunteer is about to spend 90 days on his back. I guess if a NASA activity doesn't involve the CEV or overpriced lunar landers, PAO is uninterested.
Earthbound Astronaut Stands Up - And NASA Ignores Her (previous post)

