We already use blood and blood products to improve health and performance. We already know that hematopoietic stem cells (HSCs) from adult hosts can be released into the circulatory system to regenerate organs. We understand that cell death is suspended until long after the blood has stopped pumping.
Beat me to it! A decade(?) ago, when the media first started reporting that human stem cells were being harvested from afterbirths, for use in saving other
humans' lives - and then that politicians were getting worried about the repercussions, and passing laws - it sounded very
science fictiony "magic"!