The concept of "muscle memory" refers to the neuromuscular adaptations and increased efficiency of movement that occur with repeated training of specific exercises. When individuals train consistently, their bodies become more adept at performing those movements, enabling quicker strength recovery and skill reacquisition after periods of inactivity. Muscle memory is facilitated by changes in the muscle’s structure and the nervous system's capacity to recall previously learned movements, making it easier for individuals to regain lost strength or skills when returning to training.