When a fit person stops working out, the defined muscles will fade and eventually seem to disappear. So why is it possible to build the same amount of muscle faster when returning from a break? How long can a break from working out actually be without having to start from scratch again?
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This might just be selection bias. You’re comparing two groups:
* People who have had defined muscles, have lost them, and are trying to regain them
* People who have never had defined muscles and are trying to gain them for the first time.
You observe that the first group generally shows faster improvement. But that doesn’t mean that them being ripped before is causing them to show faster improvement. Maybe it’s just that this group, by definition, excludes those who were unable to gain defined muscles at all, meaning that this group is selected to be more athletic.
The muscles are still there, just deflated or compressed.
There’s a concept called muscle memory. There’s a lot to it but basically your muscles remember being bigger and stronger before and have an easier time rebuilding it than those that don’t have it. Also your muscles don’t go away, even if you don’t lift for a while, as long as you aren’t losing excess weight you will still retain a decent amount of muscle mass, so it also appears to come back faster.
Also on top of this, people who where previously fit tend to have more skill and dedication compared to new lifters, so will see results quicker cause they are better and more consistent at lifting and diet in the first place
there’s a difference between hypertrophy (muscles that look actually big) and having muscles. they can be related, but they are not the same. in general, fit people who have built muscles will generally retain those muscles for a while even if they “deflate” seemingly pretty quickly.
relatedly, if you already have the muscles, the phenomenon of looking “pumped” after a workout is going to be much more pronounced for a fit person getting back into the rhythm of exercise than for someone building the muscles in the first place, and it’s going to look like the fit person made a bigger “comeback” even though it’s mostly just appearances.
Muscles are like ropes – if you’ve ever seen a rope, you’ll notice it’s a bunch of strands twisted together.
When you work out and build muscle, you’re making those strands bigger, and also adding new strands.
When you stop working out, over time those strands will shrink – but you still have more than before, and they’ll be quicker to grow back since they’ve done it before.
It’s possible that its not about being able to build muscle, but how to build muscle.
There will be routines and learnings from when they previously built muscle that they can focus on to more effective work out.
Myonuclei in a word.
When you gain muscle, you not only increase the quantity and size of your muscle cells, you gain myonuclei.
The size of your muscle cells can shrink, and the quantity of fibers can reduce, but myonuclei are ‘sticky’. Think of myonuclei as the assistant control centre for the muscle cells. They support the nucleus with most of the cells function which is unique to cells.
So they can help your existing muscle cells synthesize protein for growth, repair damage, and assist with other cell functions meaning you’re more efficient for those kinds of functions than back in the day before you had all those extra myonuclei.
They stick around for a long time, maybe even indefinitely. So once you’ve earned them, you mostly keep them it seems.
When you work out over time you slowly gain more muscle nuclei, and gain muscle fiber. When you stop for a long time, those muscle fibers atrophy in size, maybe even back to your starting level but those gained nuclei still are there still.
The next time you start lifting consistently, you pick it back up faster and can more easily get back to your previous levels because those nuclei are still there. It’s like how a small business might buy equipment and systems and processes after they start up, building up and fine tuning things as time goes on. If they were to put things on pause for a year or two, it would easier to start things back up because the infrastructure is already there from before.
This is what people mean when they describe “muscle memory”.
Long term strength training creates a higher density of a cell within the muscle fibers called “myonuclei”. These cells function like a factory facilitating protein synthesis and repair and persist for a decent amount of time. So even if you don’t work out for a long time and the muscle loses mass, the myonuclei remain so when you strength train again, the presence of a larger density of myonuclei “factories” causes more rapid hypertrophy (muscle mass gain) in response.
When your muscles grow enough, they eventually need more nuclei to support the capacity needed to sustain themselves. This process is permanent. Even if your muscles shrink due to lack of exercise and/or diet change they grow more effectively due to the increase in nuclei (when you apply proper diet / exercise). Also, muscle memory and having knowledge of technique / diet required can be helpful in making the process more efficient.
As someone who just came back to the gym after a long depression of 2 years ,wow, it feels so good! I can really feel all the muscles being there, and I’m hitting them when I do exercise. When I started working out back in 2021, it took me a very long time to feel all the muscle, and like many said, when you are new, it just takes time to develop those muscle.
Now, I’m doing my old stuff, old rutine, and so on. The only thing I miss is I lost my strength, but we have to keep grinding, baby 💪
There are underlying structural changes (more fibers, more vascularity, neurological improvements) that happen when you work out. These don’t go away after the muscle atrophys.
Hey there! Think of those muscles as a friendly old neighborhood that gets quicker to spruce up once you’ve visited before—it’s like they remember the good ol’ days! When you’ve had muscles in the past, your body can “rebuild” them faster due to muscle memory, saving you from starting all over again. So, take that break, but not too long; those muscles are patiently waiting for some action!
A yuuuman is the most complex mechanism on Earth. Long story short: no one knows exactly why. There are plausible theories, and some bits and pieces of knowledge on what goes on (in the muscles, in the nerve endings within those muscles, in the brain), but we’re nowhere near having it all figured out.
It definitely has more to do with the nervous system than the muscle fibers themselves, however. Strength, in general, is more about the nervous system than the muscles themselves: about the ability of the brain to control the muscles. And that ability needs to develop, along with the muslces, and hangs around for a long time, especially in the brain. Also, developing it actually takes a slightly different approach than muscle building. Different sets, different loads, different effort level, different mindset. Andrew Huberman talks a lot about this.
Not saying the guy talking about myonuclei is wrong. That’s true too. But it probably has more to do with the nervous system being ahead of the curve already, the second time around.
Also, skill and psychology are almost certainly a big factor. Training (be it lifting weights or bodyweight exercises) is a skill. Not an easy one, either. The second time around, you train far more efficiently, because you know what you’re doing. You’re more confident, too, so you push yourself harder. And you know that, if you do the work, the results will come, because you’ve done it before. There first time around, there’s often that creeping feeling of “what if I’m just wasting my time, moving weights back and forth like an idiot … what if I’m wone of those non-responders who can lift all day and not put on any muscle?”.
Without getting into the science of it, you have built a foundation if you’ve been muscular before. It is a lot easier to build a house when the foundation is already there.
Eli5: When getting big and strong, the muscles increase their number of nuclei, which are like muscle building factories. After taking a break from exercise, those factories slow down, but don’t go away. When you start exercising again, the factories are already there to help build bigger muscles faster than before. These extra factories are thought to last for a very long time, or for a lifetime in some cases once they are built. Also, once you have exercised before, your brain and body don’t have to relearn how to exercise, they quickly remember how it feels and how to push hard enough to make those factories build muscles.
More complex: Many have answered correctly that myonuclear addition, or accretion, is thought to be the primary mechanism that allows easier regrowth of muscle after a lapse in stimulus/training. Simply put, more myonuclei = more protein factories.
Many are incorrect in stating that muscle fiber number increases. That is called hyperplasia, and while it is possible in animals, humans do not experience hyperplasia in any measurable amount. Human skeletal muscle grows exclusively through hypertrophy, a gain in size of the existing muscle fibers by added sarcomeres and increasing contractile components, enlarging the cross sectional area of those fibers.
Source: masters in exercise physiology, partial PhD in exercise physiology, doctorate in physical therapy
I stopped working out for a long time, maybe 12 years. And I work on a computer all day, so my job doesn’t keep me fit. I recently started lifting weights again and I put muscle back on fairly quick, especially quick in my mind because all I have is two adjustable dumbbells that don’t go past 52 pounds, and I only lift a few times a week, if any some weeks.
So 12 years seems to not be too long.
Regaining muscle through muscle memory is easy. Building NEW muscle, especially if you’re already in peak condition, can be exceptionally difficult. If you were to take an experienced weighlifter/bodybuilders put them in a race with a novice with no experience whatsoever in lifting weights as to who can add a whole inch of muscle to their upper arms first, the novice would win by a mile. Because the body reacts to new stimulus it’s not used to very effectively.
If this is true why is it so commonly said that people working out for the first time put on muscle the fastest? (Newbie gains).
The mitochondria is the powerhouse of the cell
You don’t so much lose cells as they replace the contents with other things. The body is great at using unused muscle tissue. You get some lipid storages, but it’s not nearly as efficient as a fat cell. It can contribute to insulin resistance.
But in short, like fat cells, when those muscle cells go unused, they don’t really go anywhere for a long time.
Sure, you lose strength, but that’s mostly glycogen stores, and then if they stagnate, fat can be deposited in them, but overall muscle fibres like fat cells take a long time to degrade the contents of th le cells however l, not so much.