To learn more about what's happening on the International Space Station at any given time, check out NASA's frequently-updated ISS blog or their page about the research and development work happening on ISS.
Depends on your body type and metabolism and your routine. But usually it takes around 3 to 4 weeks for visible results. For me it took me a couple of months to actually see any progress visually.
Duration. Muscles begin to swell about two hours after exercise. Swelling peaks on the fourth day, then gradually subsides, returning to normal seven to eleven days after a workout.