Table of Contents
The first results, which you start to see in the mirror thanks to exercise, can quickly boost not only motivation but also ego. This is of course is fine, because in addition to the health benefits, exercise also brings higher self-esteem, improved stress management, less anxiety and a better mood. Seeing muscles in the mirror that are a reflection of long and hard work is priceless. However, life brings about different situations and it can be very easy to fall out of routine. In comes the fear that you will lose the muscles that you have been building for so long. What about muscle memory then? Can muscles remember that they were once strong and large?
Muscles adapt to loads with exercise
As long as you regularly load the muscles through exercise, they will grow and get stronger. It is an adaptation to increasing load. Therefore, it is important to progressively increase the load. If the load does not increase over time, the muscles will not have enough stimulus to grow and get stronger either.
The load can be increased in a number of ways:
- gradual weight increase
- increasing the number of repetitions with the same weight
- increasing the range of movement
- slowing the negative phase of the movement to increase the time under tension
- improving exercise technique and muscle mind connection
All of these approaches ensure an increase in tension in the muscle fibres and thus stimulate their growth. The increased tension causes a certain amount of damage, which is continuously repaired by the synthesis of new proteins. [1]
What are muscle fibres?
Muscle fibres are essentially muscle cells, but they have a slightly different structure than a typical cell. They are long and have multiple cell nuclei.
As muscle fibres enlarge over time, their energy consumption also increases. In order to grow, they need large amounts of protein, which must first be produced. Protein from your diet does not go straight to your muscles, but is digested and broken down into individual amino acids. Only the proteogenic amino acids are used to form new proteins in the muscle fibres, which consumes a large amount of energy. This is why most glucose metabolism takes place in the muscles.
If by chance there comes a time when you stop exercising, the principle “use it, or lose it” applies. Muscles that are not used are a burden to the body. They consume a lot of energy. Therefore, after prolonged inactivity, muscles shrink in volume – they atrophy. This is an evolutionary adaptation whose purpose is to conserve energy. But do you lose your muscles forever?
You might be interested in these products:
Do muscles have the ability to remember?
The ever-increasing energy consumption during the ever-increasing protein production in the growing muscle fibre must be met in some way. Muscle fibres are really huge cells in which one single cell nucleus would not be enough. In the nucleus important processes take place leading to the production of new proteins.
The cell nucleus contains all of the cell’s DNA. From this DNA, an mRNA molecule is transcribed when necessary, which acts as a guide for the production of proteins. The nucleus is the site of the cell’s relatively large energy consumption. Multiple nuclei, distributed throughout the muscle fibre, ensure that each part of the muscle fibre has an immediate supply of ‘instructions’ for protein production and does not have to rely on a single nucleus.
Muscle fibres (cells) of the skeletal muscle. Each has a large number of nuclei.
As protein production increases and muscles grow, new nuclei are also formed. Their number grows as the need for protein production increases to meet the demands across the entire, often several centimetres long, muscle cell.
Epigenetics also plays a role in this. Several genes are more active after regular exercise. This increased activity is maintained for up to 22 weeks. However, the function of several of these genes is not completely clear. [2]
What happens when you stop exercising?
Muscles begin to shrink, because it is not energetically advantageous to maintain them at their original volume. Muscle consumes approximately 3 times more energy than adipose tissue. [3] However, the nuclei of the muscle cells remain in the numbers they formed during regular exercise.[4] Although the muscles shrink, their still present nuclei function as memory.
After what period of time do you start to lose strength and muscle volume?
If the break from exercise lasts less than three weeks, you shouldn’t see a significant loss in strength. While you may not lift your original record, it will only take a few workouts to return to your original strength. As far as muscle volume is concerned, after only 2 weeks it may seem that you are losing muscle. However, the truth is that most of this loss is due to less water and glycogen in the muscles. Significant losses in muscle fibre size initially occur after 4 – 8 weeks without exercise. It all depends on the original muscle size, the duration and construction of the training plan, and genetics. Loss of muscle mass is also affected by whether you use your muscles or are immobile or bedridden during the period without exercise. In this case, the losses will be much faster and more drastic. [5-7]
Image source[4]
If you return to exercise, the muscles have pre-prepared cell nuclei that can produce proteins much faster than when you first started exercising. Getting back to your original form and gaining muscle mass is much faster thanks to the original nuclei of muscle fibres. Depending on the type of sport, the original exercise and individual variability (genetics), your original physique can return in a matter of weeks. However, it again depends on whether you progressively increase the load. Also, the recovery itself is better due to muscle memory and hence muscle soreness should be more tolerable.
However, you need to start gradually. After a long break, you certainly won’t be able to lift as much weight as you used to. Fewer sets with less weight is a more sensible start even for an experienced person who has stopped and started exercising again. Fortunately, progress will be faster than in the case of a complete beginner.
Conclusion
A longer break from exercise is no disaster. Life brings different situations and it may not always be possible to maintain your original diet and exercise regime. Even if the break happens to be so long that your muscles start to shrink, nothing terrible is happening. Thanks to muscle memory, which is provided by the new and long-lasting nuclei of muscle cells, you can get back to your original form quickly and efficiently. The great news is that these nuclei are retained in muscle cells for up to 15 years.[8]
However, when returning to exercise, it is necessary to start gradually. Despite the presence of nuclei, it is necessary to get used to exercising again and not to overdo it. This comeback, however, will be a little easier.
[1] Schoenfeld, Brad J. The Mechanisms of Muscle Hypertrophy and Their Application to Resistance Training – 10.1519/JSC.0b013e3181e840f3
[2] Seaborne, R.A., Strauss, J., Cocks, M. et al. Human Skeletal Muscle Possesses an Epigenetic Memory of Hypertrophy – https://doi.org/10.1038/s41598-018-20287-3
[3] Wang, Z., Ying, Z., Bosy-Westphal, A., Zhang, J., Heller, M., Later, W., Heymsfield, S. B., & Müller, M. J. (2012). Evaluation of specific metabolic rates of major organs and tissues: comparison between nonobese and obese women – https://doi.org/10.1038/oby.2011.256
[4] Bruusgaard, J. C., Johansen, I. B., Egner, I. M., Rana, Z. A., & Gundersen, K. (2010). Myonuclei acquired by overload exercise precede hypertrophy and are not lost on detraining – https://doi.org/10.1073/pnas.0913935107
[5] McMaster, Daniel Travis et al. “The development, retention and decay rates of strength and power in elite rugby union, rugby league and American football: a systematic review.” – doi:10.1007/s40279-013-0031-3
[6] Léger, B., Cartoni, R., Praz, M., Lamon, S., Dériaz, O., Crettenand, A., Gobelet, C., Rohmer, P., Konzelmann, M., Luthi, F., & Russell, A. P. (2006). Akt signalling through GSK-3beta, mTOR and Foxo1 is involved in human skeletal muscle hypertrophy and atrophy – https://doi.org/10.1113/jphysiol.2006.116715
[7] Dirks, Marlou L et al. “One Week of Bed Rest Leads to Substantial Muscle Atrophy and Induces Whole-Body Insulin Resistance in the Absence of Skeletal Muscle Lipid Accumulation.” – doi:10.2337/db15-1661
[8] Kristian Gundersen, Stan L. Lindstedt, Hans H. Hoppeler; Muscle memory and a new cellular model for muscle atrophy and hypertrophy – https://doi.org/10.1242/jeb.124495
Add a comment