Hey Angels & Alphas,
You know it, I know it, the world knows it. Many lifters nowadays are super concerned that if they go on a vacation or take a little bit more time away from the gym, their muscles will evaporate and their mass will drop like *snap* that.
Today, we’re here to talk about this concern and see how much validity there is to it.
Now, if you’ve been training for a couple of years, you’re probably aware of the fact that muscles have to be maintained, not just built.
So what happens if you stop lifting weights?
Well, researches call it detraining, but simply put, when you stop lifting weights, you’re naturally going to lose both muscle size and your current maximum strength.
Imagine today is the day you stop strength training.
In the next couple of days, you’re most likely going to experience a small increase in maximum strength. This is because muscles are being repaired, and the built-up stress in your nervous system starts easing and disappearing.
A few days after this, you’ll start seeing small drops in maximum strength. This could technically be as a result of lower motor unit recruitment and losses of coordination (from not doing certain exercises for a while).
However, over the next month or so after that, you’re going to see continuous reductions in strength most likely due to losses in muscle fiber size. It’s a slow and steady process, but muscle size is usually the first to go.
After these 4 weeks, when muscle size stabilizes, you’re probably not going to lose much more size.
Why do we lose size first and strength second?
Your muscles are made up of dozens of thousands of muscle fibers, grouped in a couple hundred motor units.
When your body needs to perform a task, motor units are recruited by the central nervous system. This is done in a specific order related to the muscle recruitment threshold.
Low-threshold motor units are always recruited before high-threshold motor units. In addition, when high-threshold motor units are recruited, low-threshold motor units remain recruited.
Low-threshold motor units control a couple dozen muscle fibers, and high-threshold motor units control thousands, even tens of thousands, of motor units.
Do you follow me so far?
The heavier and more intense the task is, the more motor units are needed for the completion of the movement. That being said, if the action also involves a slow muscle fiber contraction velocity, then the muscle fibers will experience time under tension. This mechanical loading stimulus triggers increases in muscle-protein synthesis.
And technically, when you’re on a strength training regime, you’re providing this mechanical loading stimulus to the muscle fibers of your high-threshold motor units.
When you stop doing this, the muscle fibers stop receiving this regular stimulus. Therefore, they begin to atrophy. This is only natural.
However, low-threshold motor units experience enough “time under tension” to remain a constant size even when you’re just going about your life. (Mostly because of gravity.)
This explains why you experience rapid decreases in muscle size after you stop lifting.
Muscle fibers controlled by high-threshold motor units lose the usual stimulus they experience, while the muscle fibers stimulated by your daily life activities are unaffected.
Did you know? If you have a job that’s rather physical, you’ll experience less muscle atrophy then someone who sits at a desk all day. This is because the number of muscle fibers that will remain unaffected will depend on the type of activities you do in your daily life.
What happens if we take a break from strength training, but then decide to start lifting again?
When you stop lifting for short periods of time, you’ll lose muscle size because you’ve removed the regular stimulus your high-threshold units need to remain at their current size.
This means that, if you take a break from strength training for a week, high-threshold motor units will still atrophy, reducing overall muscle size.
But here’s the kicker! When you start lifting again, hypertrophy occurs way faster than it did the first time you trained.
This might happen because of two reasons.
First – epigenetic memory. This is information about a muscle’s maximum size in the past that is stored inside your muscles. Some people believe that this memory is related to a higher number of myonuclei. Myonuclei are not lost while detraining despite the losses in muscle size, and they permit an increasing resting rate of muscle protein synthesis. Therefore, it’s much easier for muscles to return to a size they previously had.
Second – motor unit recruitment decreases way slower than muscle fiber size. When you return to lifting weights after a few weeks of detraining, you’re able to recruit more motor units than you could the first time you started lifting. Because of this, you can load more muscle fibers, therefore increasing their combined size super quickly.
Once you know all of this, there are probably a couple of questions that arise in your head.
What about deloading? What about short breaks from strength training?
Will they help us enhance hypertrophy? Or are they actually counterproductive when you’re trying to build size?
Can we improve hypertrophy by taking these short breaks from lifting?
Over the last few years, a lot of researchers have proposed that accelerating muscle growth might be possible by deliberately taking short breaks from strength training.
However, I feel like this is unlikely. Muscle growth is quicker during a period of training *after* a period of detraining. Compare that to when you first started lifting weights, when your muscles were rapidly adapting to the new stimulus and growing as fast as they naturally could.
That being said, while the rate of muscle growth will definitely be faster after a period of detraining, this will only be present to the point where the lost muscle is regained. After you reach your past top form, the same slow rate of gaining will come back.
(This means we *cannot* artificially bring about increases in the number of myonuclei by taking short breaks off the weights.)
While it’s a fact that taking time off training will lead to more muscle damage in the first workout after coming back, it doesn’t lead to any *new* muscle gains. Myonuclei are closely related to the rate of repair of your muscles instead of increases in muscle size.
When you start lifting again after a break, myonuclei will be put to work. But this doesn’t indicate that any new myonuclear addition is happening. It’s more or less a measure of how cells are working to repair the damage.
If this is true, why do we deload?
Deloads remain incredibly crucial for all athletes, not just those focusing on strength.
Sometimes, we just have to take breaks off strength training to allow our central nervous system fatigue to evaporate.
However, it’s also true that merely decreasing volume will be better, since this will allow fatigue to evaporate without any losses in muscle mass.
Then what are the downsides to taking breaks off the gym?
Besides the obvious decrease in mass and strength, there might be another reason why you would want to stay away from regular breaks off the gym.
Until recently, it was thought that there are absolutely no downsides to taking a break. Moreover, with you being able to return to your past top shape relatively quickly, breaks seemed rather incentivized.
But as I said, this was only true until recently.
Latest research points to some new insights.
The study I linked to basically concludes that repeated periods of loading and unloading may lead to collagen accumulating in your muscles. This, in its own right, makes them stiffer and more prone to injury.
However, the fact remains – you’re much better off with a deload than you are with a full break from the weight room.
We now know that muscle growth occurs in the 48 hours after a muscle is stimulated by heavy weights.
In addition, deliberately putting your strength training to a halt for more than a week *cannot* help you enhance muscle growth. That being said, this *will* help you get rid of accumulated central nervous system fatigue, which essentially means you will be removing a huge roadblock to your future growth.
If you stop lifting weights, muscle loss will happen. You will experience rapid losses in both strength and size for up to 4 weeks after you stop strength training, or at least to the point of equilibrium with the mechanical loading you experience through other activities in your daily life.
But fortunately, when you start strength training again after a period of “detraining,” you will experience just as rapid muscle size and strength increases!
This means that, for you, the lifter, taking a break is not as scary as it looks.
Don’t worry – even if you take a few months off the gym, you can get back to where you left off pretty quickly.