We wrap up the microgravity series by focusing on the countermeasures used to fight physiological decline in space. These include treadmill harnesses, cycling, resistive training, and pharmacological strategies like calcium, vitamin D, and bisphosphonates. We also discuss the challenges of returning to gravity, including orthostatic hypotension, weakness, and vestibular disorientation, as well as the long-term risks of extended missions. Finally, we explore future solutions, such as artificial gravity and gene-based therapies.