Yes, muscle memory is a real thing, but it might not benefit your workout in the way that you think.
Muscle memory is one of those things that totally makes sense if you don't think too hard about it: You squat like a beast every week for years, then you're forced to take months off your practice. When you start up again, your muscles "remember" your squatting history, allowing you to rebound faster than someone who's never done the move in their life. (Whether you're a pro or a novice, this 30-day challenge will take your squat game to the next level.)
But when you really think about it, the whole concept starts to seem a little fishy. Can your muscles really remember workouts you used to do? And what does that mean, exactly?
"Muscle memory really has to do with the nerves that communicate with the muscle to allow them to move in the proper sequences for certain movements," says Cedric X. Bryant, Ph.D., the chief science officer at the American Council on Exercise. "The order in which you activate the muscles becomes engrained," he explains. (Visualization contributes to muscle memory, too.)
Take swimming. If you swam competitively in high school and college, the nerves that tell your muscles when to move in order to form a front crawl, for example, get super-good at their job. And even if you go years without swimming after your graduate, when you return to the pool, you'll be able to move back into perfect front-crawl form faster than someone who's learning to swim from scratch (given, of course, you had good form as a student-athlete).
But as for whether you'll actually get into shape faster—no dice. "In terms of physiological changes, the difference between someone who used to do a sport but is not deconditioned and someone who never has before won't be that significant," Bryant says. "Both will have the same challenges of the muscle adapting to the new stress of exercise."
Bryant says that the only way to develop muscle memory in the first place is repetition, and making sure you're using the proper form when you do practice. "Muscle memory can be positive or negative, depending on the technique," he cautions. (See also: The Best Ways to Pump Up Your Mental Muscles)
But researchers from Johns Hopkins University discovered at least one way to boost muscle memory. They found that people who had to slightly modify their practice routine learned twice as quickly as those who practiced the exact same thing day in and day out. The study authors say it's thanks to a phenomenon called reconsolidation: When you change your routine slightly, your brain recalls and modifies existing memories with the new knowledge, making them even stronger and giving your motor skills an assist. So if you're trying to perfect your tennis serve, changing to smaller racquet for some of your practice sessions may help you learn the move more quickly. For more complicated moves, try pretending you'll have to teach the movement to someone else at the end of the day.