Astronauts can become as weak as 80-year-olds after six months at the international space station, according to a study that raises health concerns as NASA contemplates trips to asteroids and Mars.
Marquette University biologist Robert Fitts, who led the study, stresses that the accelerated space aging is temporary: Astronauts' muscles recover after a few months back on Earth.
Astronauts can avoid becoming weaklings, however, with more research and the right equipment for hitting the space gym, Fitts said.
Fitts bases his findings on calf-muscle biopsies that his team collected on nine U.S. and Russian space station residents from 2002 to 2005. It is the first muscle study of long-flying astronauts that gets down to the cellular level.
The researchers discovered that the astronauts had lost more than 40 percent of the power in the slow-twitch fibers of their calf muscles. Those are the muscles so crucial for balance and posture, and seem to take more of a space-beating than other parts of the body.