How to fill a new Habitat?

> > The human body needs gravity in order to survive in
> > the long term, but.
> >
> > What would happens if a human being live and work in a
> > weighless environment, but have the chance to sleep in
> > a kind of centrifugal room?
> >
> > That way, about 8 hours a day he will be exposed to
> > a gravitational field, that is, a third of his time.
> >
> > Could that compensate for long time exposure to
> > weighless environments?
> >
> > Just for curiosity.

One of the effects of living in zero-g is the muscles, with so little
required of them compared to living in gravity, tend to get smaller and
weaker.

Did anybody see the news story about the super strong toddler in Germany?
The point of that piece is that researchers, learning from that baby and his
remarkably muscular family, learned that they had a genetic defect which
meant that their bodies couldn't make a substance called myostatin. This
enzyme, which most people have, turns off the process of muscle building
once it's done. So with very little exercise or stimulation, this kid and
his older relatives could maintain very strong muscles. The authors
suggested that myostatin-blocking drugs might protect against muscle mass
loss for people with diseases like muscular dystrophy, *and* astronauts in
zero-g for long periods. I'm sure NASA and others didn't miss the
implications of this.

Myostatin blockers wouldn't stop the bone mass loss that also happens. It
turns out that bone tissue changes, which occur all the time, begin once we
go to bed. It has been found that if a person does a new type of activity,
say starting an exercise routine that is different from what they have been
doing, that within a few months his or her bones will begin to reshape to
handle the physical forces of the new activity. We know that this reshaping
happens at night, during sleep. So sleeping in a centrifugal room after
working zero-g all day probably wouldn't work to preserve bone mass. The
only saving grace is that bone mass loss is a process taking months to
years.

Cardiovascular efficiency loss in orbit may or may not be a byproduct of
muscle mass loss, we'll have to see.

Hope that helps,
Brad