Whether it’s riding a bike, playing the piano, or hitting a hole-in-one, there are things you never forget to do. And the reason for this phenomenon is thanks to something called “muscle memory”.
Muscle memory applies to a wide range of physical activities, from playing an instrument to sports. But although we need to practice a movement repeatedly in order to develop muscle memory, the term does not refer to the ability of muscles to remember movements. Rather, this “memory” occurs in our central nervous system, which is why many of us can retain skills learned in childhood, even if we haven’t used them for years.
But muscle memory doesn’t just apply to skills and physical movement. It turns out muscle memory can help us out in the gym, especially if you’re trying to get back in shape after a break.
Types of muscle memory
There are two types of muscle memory.
The first type refers to our ability to perform physical tasks automatically and easily. By practicing a movement repeatedly, it allows you to perform those movements more automatically, without having to think too much before doing it. This is why athletes will practice a specific move or shot over and over, so they can execute it quickly and accurately under the pressure of competition.
At its most basic, this type of muscle memory involves the development of neural pathways that help our brain communicate more effectively with our muscles. This happens through a process called myelinationin which the myelin sheath (an insulating layer that surrounds nerve fibers) becomes thicker and more efficient at conducting electrical signals in the body and brain.
Studies show that myelination is improved by repeated practice of a physical task. Even relatively brief periods of practice can lead to significant changes in the brain and body that promote the development of muscle memory.
But it’s important to note that not all reps lead to muscle memory. This only happens when you engage in deliberate practice – meaning you perform specific movements or activities with focused attention and effort.
Back to fitness
The second type of muscle memory applies to our ability to get in shape.
Let’s say you were someone who, until recently, had never lifted heavy weights in the gym. You probably remember how awkward and difficult these exercises were when you first started, and how much gradual work it took to get to lifting heavier weights.
Now, let’s say you took a break from training and came back several months later. You may have found that despite having free time, it was quite easy to get back to the weights you were lifting before.
It’s because of muscle memory. It applies to all the exercises you do and can make it easier to regain lost muscle mass compared to the first time you build muscle.

The mechanisms behind this type of muscle memory are not fully understood. But our current theory is that even when muscle shrinks, muscle cells remain.
In order to build muscle, they must be under stress, for example during exercises such as weightlifting. This stress triggers the growth of muscle cells, helping us to become stronger.
For a long time, it was believed that if you didn’t use your muscles, those new cells would die. But research suggests that may not be the case, with a Conclusion of the 2016 study that myonuclei (a part of the muscle cell that contains genetic information and also acts as a key indicator of muscle growth) actually only shrink when we’re inactive – they don’t shrink at all. While more research is needed to help us fully understand this process, it at least suggests that our bodies use myonuclei to build up our fitness capacity – which would explain why it’s faster to get into shape the second time around.
But if you’re wondering how long it will take you to get back in shape after a break from training, unfortunately, that’s not that easy to answer and it will vary from person to person.
The rate at which muscle is recovered may also depend on the level of inactivity you had during your training break. For example, he can take longer to get back into shape if you’ve been bedridden for months versus if you just stopped resistance training but continued with your normal daily activities.
In the last case, a study in women showed that even after more than six months off, participants were able to regain their pre-break muscle strength and size during six weeks of retraining compared to the 20 weeks of strength training it took them to get in shape initially. Another study found that men and women who trained for ten weeks and then took 20 weeks off were slightly stronger and slightly more muscular after five weeks of retraining than they were after the first ten weeks of training .
While there’s still a lot we don’t know about muscle memory, the good news is that it’s never too late to get back to the gym, even if it’s been a while. Although it may feel like starting from scratch at first, the gains will come back in no time. But while it may be tempting to go back to what you were doing before taking time off, it’s important to listen to your body and gradually reintroduce yourself to the gym to avoid injury.