If the simple version of that hypothesis is true, then why is exercise so beneficial? Even in 1g our lifespan suffers if we don't regularly stress our body. Ma

If the simple version of that hypothesis is true, then why is exercise so beneficial? Even in 1g our lifespan suffers if we don't regularly stress our body. Maybe in 0g it is possible to find a better balance with lower baseline stress, with regular high-stress periods. But any ideas on how to even reach earth-equivalent levels of healthiness require much better space stations than what we have or build today