Often quoted but rarely discussed in detail, it is often claimed that muscle has memory.
It has been stated that muscle remembers the size it once had and will regain it quickly.
In a very recent study, this has been shown to be correct.
This is because A muscle can gain nuclei, but never loses them – ever.
As stated in the study “It appears that once acquired, myonuclei persist even when a muscle becomes atrophic or initiates cell death.”
This has uses beyond bodybuilding. It may help those who simply want a better quality of life when older “Informing public health policy, the discovery that myonuclei are retained indefinitely emphasizes the importance of exercise in early life. During adolescence muscle growth is enhanced by hormones, nutrition and a robust pool of stem cells, making it an ideal period for individuals to “bank” myonuclei that could be drawn upon to remain active in old age.”
You can see the study here – https://www.frontiersin.org/articles/10.3389/fphys.2018.01887/full