"As part of my flight training to the International Space Station (Exp 40/41) we astronauts need to stay in good shape. Not only to better cope with the stress of launch, but to actually stay healthy in zero gravity. Extended stays in reduced-gravity environments can cause a number of negative health impacts on the human body. One significant challenge is the potential for loss of bone density that crewmembers experience after traveling in space. After just a few days in space, reduced gravity begins to impact muscle density and function. That is why exercising prior and during a mission is so important. #NASA #Health #Space #STEM #Medicine #Gym"