In a zero gee environment (weightlessness), the Human Body almost immediately begins losing muscle and bone mass.
If they did not exercise, Astronauts returning from Space after a long stay on the Space Station would be unable to walk, and would have to be in a wheelchair for weeks before they could learn to walk again.
astronauts like to exercise while in the ship
If the space station is pressurized, I don't think astronauts need to where space suits.
The International Space Station normally has a crew of three or four, and while they rotate, most astronauts do not get to live on the space station. As of Feb. 2010 the number is now up to 6.
Astronauts can perform their space walk and move around as if nothing is happening while the space station is traveling at 17,500 miles per hour, because there is no gravity. This keeps them from feeling the fast speed.
Astronauts should and do exercise in freefall
I don't think that they do. However astronauts skeleton's do tend to lose some of their calcium while in space. This is because the lack of gravity means that the skeleton is not stressed. To try and prevent this calcium loss astronauts try and exercise hard (to stress the bones) if they are in space for a long period.
to me if they run out they used a urine filter then drink the water
You will tie your shoelaces to the bedpost, or, as astronauts do in the International Space Station, strap yourself to the bed.
While on a mission - probably not. Crumbs that get airborne is a concern in a spacecraft/space station, so muffins wouldn't be particularly suitable...
Space Adaptation Syndrome
no
Astronauts use a variety of tools while in space. For instance, astronauts use specially designed tools, like hammers and wrenches, that are made to be used with unwieldy space suits.