Is there a more misconstrued concept in all of broscience than muscle memory?
Most imagine muscle memory works this way; as you stop exercising, you lose your size and strength, but because you already had it, you regain it faster the second time around.
It gets even murkier when wondering how long it takes to lose muscle, or how fast the recovery usually is.
So how far off base is the broscience?
“Muscle memory is the ability to reproduce a particular movement without conscious thought, acquired as a result of frequent repetition of that movement.” That’s the dictionary definition.
However, that’s not how most of us think of it. Instead, we think of muscle memory as the mechanism which enables quicker size and strength regains.
The size and strength dichotomy, in particular, goes beyond semantics. It’s a worth distinguishing before we can arrive at any conclusions.Specifically, muscle memory affects strength regains differently than muscle mass regains.
Hence, if you’re retraining, size and strength aren’t regained at the same rate.
Because of the distinctions, “muscle memory” is a subjective term. A bodybuilder that meticulously tracks their lifts and nutrient intake may view the retraining process differently than someone who’s less fastidious.
To account for the subjectivity, we’ll go over what muscle memory is, and how it works with muscle mass, as well as strength.
Process, Process, Process
The way most of us think about muscle memory isn’t far off base. Here’s the basic process in simplified form;
- As you train, you initiate muscle growth. Specifically, you’re damaging tiny strands within your muscle fibers, called myofibrils.
- To repair the tears, the body directs proteins (cytokines) to order surrounding muscle fiber satellite cells to fuse the torn myofibrils together.
- This regenerates and increases the myofibrils and by extension, muscle fibers.
Throughout the hypertrophy process, muscle fiber satellite cells fuse to the myofibers and “thereby increasing the capacity for protein synthesis.” This fusion creates “extra nuclei which seem to remain part of the fiber even during subsequent atrophy as muscle memory.”1
Finally, the number of nuclei is crucial as it’s an “important condition for regulating muscle size.” After all, the newly acquired nuclei are atrophy resistant even through prolonged and severe inactivity periods. Essentially, increased overload derived nuclei make muscle memory and quicker retraining possible.2
So how Long is the Process?
So we understand the process. but how long does retraining take? There are a lot of factors to consider, the most important; how long you were inactive and your inactivity level. You’ll also consider your prior fitness level, age, etc.
For example; if you were bedridden, you’ll take longer to recover. But if you took time off because of other priorities, the marginal activity levels will enable shorter regain periods.
Putting a number value on all these factors is a different matter. How much faster does muscle memory work for strength than size? Does an athlete recover faster than the casual gym goer? Fortunately, there’s research addressing the specifics.
Muscle Mass Recovery Time
Regaining strength takes longer than regaining muscle mass. That’s the most important muscle memory related takeaway.
A 2015 University of Copenhagen study3 revealed that “after two weeks of immobilization, bicycle training three to four times a week for six weeks was not enough for the participants to regain their original muscular strength.”
However, the retraining was “sufficient to help people regain lost muscle mass and reach their former fitness level.”
Hence, the subjects took three times the amount of time they were inactive to regain their lost muscle mass.
Strength Recovery Time
However, if you’re devoting time and energy towards your fitness, you’re after more than size, you’re after strength as well. Strength is the other side of the coin. Size and looks matter, but they don’t get your lifts up.
You’ve worked hard for your strength gains, progressively overloading your lifts week after week. Hence, putting on fewer plates induces great amounts of angst. So how much longer does it take to get that strength back?
For starters, the University of Copenhagen authors suggested weight training as the best form of strength regains.
A University of Ohio study4 took the suggestion further. The researchers subjected six participants to eight months of detraining after a preceding five-month strength training regiment.
Following the detraining period, the subjects then retrained for six weeks.
The initial detraining had relatively little effect on fiber cross-sectional area. Also, unsurprisingly, “maximal dynamic strength decreased but not to pre-training levels.”
However, “retraining for six weeks resulted in significant increases in both fast fiber types compared with detraining values.” A further seven week retraining period “accentuated the trend.”
Reconciling the two studies, here’s the takeaway; six weeks of bicycle training was insufficient for muscle memory induced strength regains, but weight training over the same time period was enough to initiate “rapid muscular adaptations in previously trained” subjects.
The research is encouraging; muscle memory isn’t just broscience, it’s real. Both anecdotal and lab derived evidence evinces that reality. But as indicated above, there are a lot of factors determining how effective and how long the muscle memory process is.
Besides our obvious genetic differences, our prior fitness levels and the subsequent inactivity levels and durations all play a significant role in regaining size and strength.
Finally, making up for lost strength takes longer than retraining for size. Luckily, both are quicker the second time around.