Way back I pointed out something about fasting - that fasting "turns on" autophagy.
Autophagy is described by this article:
Autophagy is a cellular process that occurs during states of low energy such as that seen with fasting. Autophagy literally means self consumption. During low energy states the cell actually eats itself and the internal material is recycled and used to fuel other cellular processes. It’s basically cellular energy management. So during states of fasting, autophagy takes place to reduce the number of cells, reuse and recycle the materials from the cell for fuel. The neat thing is that newer younger cells are much more adept to this process compared to older cells, which is why older cells end up accumulating, and contributing to aging. This means that regular states of fasting would keep your cells younger and more efficient.
I also pointed to research that weight training promoted autophagy.
Anyway, I saw this today that says that autophagy is essential to maintaining muscle strength:
To Keep Muscles Strong, the 'Garbage' Has to Go
In order to maintain muscle strength with age, cells must rid themselves of the garbage that accumulates in them over time, just as it does in any household, according to a new study in the December issue of Cell Metabolism. In the case of cells, that waste material includes spent organelles, toxic clumps of proteins, and pathogens.
The researchers made their discovery by studying mice that were deficient for a gene required for the tightly controlled process of degradation and recycling within cells known as autophagy. Those animals showed profound muscle atrophy and muscle weakening that worsened with age.
Researchers knew before that excessive autophagy could also lead to muscle loss and disease. The new findings highlight the importance of maintaining a normal level of autophagy to clear away the debris and keep muscles working properly.