Robert Krulwich explores how zero gravity affects the everyday habits of astronauts:
I know that an exercise bike in space is not like an exercise bike on Earth, because up there they don't have seats — none at all. "You don't need a seat," says Williams, because you don't have to deal with your center of gravity. Seats are for settling. There's no weight to settle. "Actually, I haven't sat down for six months now," she says. All you do is put your feet on the pedals and pump.
"Sleeping free" is something that takes practice, since covers float away and there is no lying "down":
Dan Barry, another astronaut, once told me he likes to sleep in a fetal curl, knees to chest. But in space you can't do that, because you're being pulled equally in all directions, so your body just naturally wants to open up. As soon as you doze off, you unfurl into the letter "C." On the first few nights in space, he Velcro-taped himself to his knees.