By Dayne Hudson
Muscle memory.
It's like a holiday at the end of the horizon, your favourite desert, or finding out your favourite band is touring again.
If it exists, it's a godsend.
You've heard all about it before; train like mad, take a few months off, then come back and regather the muscle mass you used to have rather quickly.
But is it correct? Does muscle memory exist?
Is muscle memory real?
THE RESEARCH
The good news is - it does!
Muscle memory is a real thing that's been proven quite a number of times (1).
But the way in which it works has been quite misunderstood.
MUSCLE MEMORY SIMPLIFIED
STEP 1: A newbie begins lifting weights with the goal of hypertrophy (muscle growth). Muscle fibres have multiple nuclei, and the number of nuclei increases when his/her muscle mass increases (2).
STEP 2: After 6 months with considerable muscle growth, he/she stops training for 3 months. The detraining (not training) leads to muscle atophy (reduction in muscle size) but NOT the loss of myo-nuclei (3).
STEP 3: The increased number of nuclei in the muscle fibers that have grown due to the weight training are what contributes to the muscle memory, when he or she begins training again! The seemingly rapid regrowth comes down to this.
The muscle size comes back a lot easier when they begin training again, due to the moderate increase in the protein synthesis rate of each of the nuclei.
They are essentially jumping the queue of having to gain the nuclei in the way they did during the first 6 months (3).
There is also data that suggests the newly gathered nuclei isn't ever lost (4), meaning the benefits gained from pumping iron are likely to hang around!
However, it's clear that one should be weight lifting in their youth and younger years to first gather the nuclei, as the ability to obtain new nuclei is impaired in the elderly (5).
So don't start too late!
SHRINKING MUSCLES IN 2 WEEKS
Research (6) has found just 2 weeks away from the weights room results in a "significant" reduction of muscle mass.
I'm talking about 6.4% - which is a lot when you're working hard for every last bit of it.
But of course, this is just a reduction of muscle size, and not muscle nuclei, which you now know is behind gathering back your previous level of muscle mass.
EVEN BETTTER MUSCLE MEMORY
It's another reason people turn to anabolic steriods - not only for large increases in muscle mass but for the possiblity of enhanced muscle memory as well.
The above cited study (2) into mice found that the increased nuclei in muscle persisted after withdrawing the steroids for 3 months, when the muscle mass had returned to normal.
When these muscles were overloaded again, they grew by a whopping 30% in just 6 days, while the control experiment experienced insignificant growth.
Now of course, this is a study into mice and no one is suggesting such a magnitude of results may be seen in human beings.
But the point is the possiblity for unbelievably enhanced muscle memory exists for those using anabolic steroids (which of course, I DO NOT recommend under any circumstances).
It's why many call for life bans for athletes found using these drugs, as they can benefit for a long time after usage; even when they have completly removed the substance from their bodies.
CONCLUSION
If you need to take a break from the gym, go on a holiday, or attend to something important for a while, the good news is that you can kick back knowing you really won't lose any muscle mass in the long run at all.
Call it a godsend, muscle memory training, whatever you like. The thing to know is that muscle memory is real.
I've heard many suggest that weight training with the goal of hypertrophy is silly, considering you lose all of it when you stop.
But although this may appear to be the case with the reduction of muscle size evident in the mirror and scientific data, the happenings away from the surface appearance of muscle mass don't dissapear too, that is, the muscle nuclei.
It is the nuclei gained that lives on to allow the previous state of hypertrophy to return.
So if you need a break for whatever reason, take it.
Remember: It's all about the nuclei - not the mirror.
"Stay Fit, Stay Flexed!"
REFERENCES
(1) Staron RS, Leonardi MJ, Karapondo DL, Malicky ES, Falkel JE, Hagerman FC, Hikida RS. Strength and skeletal muscle adaptations in heavy-resistance trained women after detraining and retraining. J Appl Physiol (1985). 1991 Feb;70(2):631-40.
(2) Egner IM, Bruusgaard JC, Eftestol E, Gundersen K. A cellular memory mechanism aids overload hypertrophy in muscle long after an episodic exposure to anabolic steroids. December 15, 2013 The Journal of Physiology, 591, 6221-6230.
(3) Bruusgaard, J. C., et al. "Myonuclei acquired by overload exercise precede hypertrophy and are not lost on detraining." Proceedings of the National Academy of Sciences 107.34 (2010): 15111-15116.
(4) Gundersen K, Bruusgaard JC. Nuclear domains during muscle atrophy: nuclei lost or paradigm lost? J Physiol. 2008 Jun 1;586(Pt 11):2675-81. doi: 10.1113/jphysiol.2008.154369. Epub 2008 Apr 25.
(5) Schultz E, Lipton BH. Skeletal muscle satellite cells: changes in proliferation potential as a function of age. Mech Ageing Dev. 1982 Dec;20(4):377-83.
(6) Hortobagyi T, Houmard JA, Stevenson JR, Fraser DD, Johns RA, Israel RG. The effects of detraining on power athletes. Med Sci Sports Exerc. 1993 Aug;25(8):929-35.
