Injuries & Muscle Memory
Contributors: Andrew Vigotsky
Injuries can be quite disheartening, especially if one has to break their training protocol as a result. Luckily, our body has mechanisms to help us get back to pre-injury conditions as quickly as possible.
Bruusgaard et al. (2010) investigated what exactly muscle memory is. They found that as one trains, the number of myonuclei increases. When one detrains, the number of myonuclei remains the same. More myonuclei means more mRNA and thus, more muscle protein synthesis. This is why it takes a shorter amount of time to regain lost muscle than to gain it the first time around.
Ogasawara et al. (2013) looked at the effects of detraining on muscle protein synthesis. They found that after a detraining period of 12 days, one becomes more sensitive to training stimuli.
Take these things into account when you are injured. Regaining lost muscle is not an issue, and trying to train through an injury is dangerous.
Know your limits. Train hard when you can, but rest when you need it.
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. Proceedings of the National Academy of Sciences, 107(34), 15111-15116.
Ogasawara, R., Kobayashi, K., Tsutaki, A., Lee, K., Abe, T., Fujita, S., … & Ishii, N. (2013). mTOR signaling response to resistance exercise is altered by chronic resistance training and detraining in skeletal muscle. Journal of Applied Physiology, 114(7), 934-940.