How much muscle do you lose taking a break from training?

By Elliot Fisher MS, ATC, CSCS, PES

The last handful of weeks have been difficult for most of us with the drastic societal changes from COVID-19.  Finances, social gatherings, routine, and fitness have all been affected.  During these past weeks you may have tried to workout at home or you may have taken time off completely.  The question is how much of the progress you have made before the quarantine will you lose until the gyms are reopened and how hard will it be to regain what you lost.  We’ll take a look specifically at muscle size in this blog post.

Building muscle is a long and arduous process.  It would be devastating to lose all of the progress made due to the mandated shut down in place.  However there is some good news here. 

First, it doesn’t take much work to keep muscle once it has been built.  One study showed after training, it only took one third the amount of training volume to keep gains than it took to make progress to begin with.(1) So if you only trained nine working sets before, you would only need to do three now to keep your muscle.  Doing other nonspecific activity may spare some muscle loss as well.(2)  

The other good news is that if you take a break from training and return to training, you are generally able to regain the muscle quickly and catch back to where you would have been in a short period of time.(3) This phenomenon is due to the development of myonuclei.(4)  Myoneclei are the nuclei in muscle cells.  The nuclei of muscle cells are responsible for the total amount of muscle hypertrophy that can occur.  The more you train and the more muscle you build, the more nuclei are created in each cell.  When you stop training the muscle with atrophy but the total amount of myonuclei don’t decrease.  When you go back to training you still have all of the myonuclei which can signal for the same amount of muscle to be built back.  This can be observed in the real world where athletes are forced to take an extended break due to injury and when they return to training they make an insane amount of progress in a short period of time.  

While gyms and fitness centers are still closed it is a good idea to do something to stay physically active.  If you are unable to or feel less motivated, be assured once you get back to your normal routine you will make a lot of progress very fast and get back to where you were in no time!

References:

1. Bickel, C. S., Cross, J. M., & Bamman, M. M. (2011). Exercise dosing to retain resistance training adaptations in young and older adults. Medicine & Science in Sports & Exercise, 43(7), 1177-1187.
2. Haff, G. G., & Triplett, N. T. (Eds.). (2015). Essentials of strength training and conditioning 4th edition. Human kinetics.
3. Ogasawara, R., Yasuda, T., Ishii, N., & Abe, T. (2013). Comparison of muscle hypertrophy following 6-month of continuous and periodic strength training. European journal of applied physiology, 113(4), 975-985.
4. Lee, H., Kim, K., Kim, B., Shin, J., Rajan, S., Wu, J., … & Park, J. Y. (2018). A cellular mechanism of muscle memory facilitates mitochondrial remodelling following resistance training. The Journal of physiology, 596(18), 4413-4426.