Once someone reaches a certain muscle state, if they undergo muscular atrophy and lose it, is it easier to get back to it than if they had never reached it. Is this a biological effect and if so is there a name for it? Any scholarly sources would also be really appreciated
Myonuclei acquired by overload exercise precede hypertrophy and are not lost on detraining.
Bruusgaard JC1, Johansen IB, Egner IM, Rana ZA, Gundersen K.
Effects of previous strength training can be long-lived, even after prolonged subsequent inactivity, and retraining is facilitated by a previous training episode. Traditionally, such "muscle memory" has been attributed to neural factors in the absence of any identified local memory mechanism in the muscle tissue. We have used in vivo imaging techniques to study live myonuclei belonging to distinct muscle fibers and observe that new myonuclei are added before any major increase in size during overload. The old and newly acquired nuclei are retained during severe atrophy caused by subsequent denervation lasting for a considerable period of the animal's lifespan. The myonuclei seem to be protected from the high apoptotic activity found in inactive muscle tissue. A hypertrophy episode leading to a lasting elevated number of myonuclei retarded disuse atrophy, and the nuclei could serve as a cell biological substrate for such memory. Because the ability to create myonuclei is impaired in the elderly, individuals may benefit from strength training at an early age, and because anabolic steroids facilitate more myonuclei, nuclear permanency may also have implications for exclusion periods after a doping offense.
I think so, based on my own personal experience.
A lot of training is about forging neural pathways (which is fairly well documented) and learning the movements. Those stick with you for a long time, in addition to the knowledge of how to successfully train.
So specifically from a "muscle" standpoint I don't know if any research has been done. But I've seen people who stopped training go back to the weight room and they rapidly advance.
In fact, and I remember reading up on this in Practical Programming (Rippetoe) a major problem with folks who re-enter training after a significant absence can actually pick up a lot of injuries because their CNS/muscles/connective-tissue are totally of balance.