Experiment to determine why astronauts feel weak back on Earth

Astronauts don't have it easy when they come home, and it's not just because of the change in gravity: their red blood cell production drops while they're in space, leaving them weakened on Earth. But why? That's what a Canadian experiment aboard the International Space Station hopes to find out. The research is testing red and white blood cell functions, as well as bone marrow fat levels, to see how they change before, during and after spaceflight. It should not only show how microgravity (and the resulting lack of activity) affects blood cells, but how reversible the effects are. How soon could you go back to normal?

The science should help astronauts stay healthy on future missions, whether it involves stepping up their exercise or giving them medicine. They wouldn't have to worry about being in rough shape when they return to Earth or land on another planet. However, it could also do a lot for people back on terra firma -- the effects are frequently the same for Earthbound people who are bedridden or otherwise can't move much. Even if you never head into orbit, the findings could improve your health during tough times.