The effects of microgravity on the human body are quite nasty actually. Do not believe all those science fiction stories where people travel nilly-willy without a thought of bone loss and heart problems and brain changes and gastrointestinal problems. Gravity is far more important in the functionings of our bodies than you might at first think.
So my senior design team is trying to simulate gravity in our project by spinning our station. But then we had to figure out how much spinning the human body could take before getting sick. Try walking around with a slow spinning motion for a bit. You get dizzy after only a short time (I know because I tried).
Anyway, it is most interesting work and way more complicated than we initially thought.