> long term astronauts and people who are bed ridden And those people lose a lot of bone mass, muscle mass, and need physical therapy to get back to normal fun

> long term astronauts and people who are bed ridden And those people lose a lot of bone mass, muscle mass, and need physical therapy to get back to normal function in 1G. Two months of bed rest will absolutely ruin you. There's a good reason astronauts need to be fit to begin with! 6 months in space causes bone loss equivalent of 20 years of aging. Return to Earth, do physical therapy for 1 year, and you're still "10 years older" as far as bone loss goes. (https://www.sciencenews.org/article/space-bone-loss-density-astronaut-recovery-gravity https://www.sciencenews.org/article/space-bone-loss-density-...). Generally, as far as I know, bone growth is triggered by impacts (think running etc), and is hard to stimulate with just muscle exercises.