Cell Volumization and mTOR Activation Post-Workout

Your post-training activities play a key role in deciding the extent of your training progress. Hard training promotes muscle growth but it has to be supported by the right combination of nutrients. Immediately after a strenuous workout, the muscle cells tend to enhance the protein synthesis process in order to make new proteins for muscle growth. Initiation of protein synthesis in the hours after the training helps determine how individuals respond to training in the long term. Not only is intense workout needed to activate protein synthesis, but the right combination of nutrients is equally important as well. It is important to know the fact that protein synthesis is actually a function of cell hydration. A full muscle is an anabolic muscle; however, the connection between protein synthesis and cell volumization has only been established in the recent years. This revelation has far reaching implications in terms of what people should do with post-workout nutrition to properly respond to training.

What is mTOR?

Knowing how protein synthesis is controlled is very important. When you try to contract a muscle against a heavy load, the main response is an activation of protein synthesis. The protein synthesis process is controlled and regulated by a protein called mammalian target of rapamycin, or simply mTOR. You must understand the fact that there exists a direction relationship between muscle growth and mTOR. The discovery of mTOR was massive because it has helped us measure the effects of different types of training and nutritional variables. 

3 Ways For mTOR Activation:

In order to activate mTOR, leucine, mechanical stress and growth factors like IGF, insulin and growth hormone hold significant importance. There are various ways to activate mTOR. Intense workouts supply the mechanical stress to activate mTOR through the Erk/MAPK pathway. However, you will have to utilize all possible ways to activate mTOR if you want the protein synthesis machinery to work in full capacity. Hormones like IGF, insulin and growth hormone activate mTOR through the phosphoinositide 3-kinase pathway (PI3K) whereas leucine activates mTOR through the recently discovered protein known as hVps34 and MAP4K3.

Perfect Post-workout Nutrition:

Intense training handles mechanical stress and part of the hormonal activation of mTOR. Strenuous exercise enhances the release of growth hormones, which promotes protein synthesis in trained muscles. However, this is not sufficient, as you will need an insulin raise to completely activate mTOR via the PI3K pathway, leucine to crank up the hVps34/MAP4K3 system and cell volumization.

Importance of Cell Volumization For Protein Synthesis:

Cell volumization has been known for quite some time now. A full/volumized muscle is an anabolic muscle and it has been known that cell swelling prevents protein breakdown and promotes protein synthesis in certain cells (10-12). But, protein synthesis in skeletal muscle cells is under tight control, due to which cell volumization alone is not enough to promote proper growth. Another important breakthrough in the field of cell volumization has been the discovery that mTOR signaling depends on cell volume. While this may appear unimportant at the beginning, there are various implications for what you must be doing in the hours after the workout to achieve maximal activation of mTOR and protein synthesis.

The breakthrough came in 2005 when a group of scientists found out that in order to activate mTOR, glutamine is also needed. According to this study, glutamine provided two major functions, both of which hold prominent importance for mTOR activation. First, it was required for leucine uptake. Second, glutamine pulled in extra water within the cell, thereby promoting cell volumization. This particular discovery was massive as it gave a direct link between cell volumization, protein synthesis and mTOR.

Cell volumization is tightly related to amino acid transport. In 2009, it was discovered that cellular glutamine influx and quick efflux is tied to leucine uptake and mTOR activation. Amino acids are transported into the cell through some amino acid transporters and an understanding of how this works can help promote cell volume and protein synthesis. The system L and system A amino acid transporters are the two amino acid transport systems closely related to mTOR signaling and protein synthesis. The system L transporters are responsible for the influx of leucine as well as the other BCAAs. The system A transporters follow a different approach. The most important thing is the fact that the coupling of these two systems ultimately allows leucine to enter the cell which leads to protein synthesis and mTOR activation.

Glycine can promote cell volumization:

Glutamine is one of many amino acids that are known as osmolytes as it transports water into the cell. Glutamine is taken out of the cell during leucine uptake by System A and System L amino acid coupling. Although glutamine is expelled from the cell to take up Leucine, there will occur no net change from this exchange since leucine is also an osmolyte. For more cell volume, Glycine can help. As Glycine is also an osmolyte, it can pull the water into the cell. Moreover, Glycine is taken up by the system A amino acid transporters, so Glycine can augment cell volume during Leucine uptake. Likewise, Glycine offers protection against inflammation and free radical damage.

The Important Role of Insulin:

Insulin is a powerful activator of protein synthesis. As a matter of fact, insulin also indirectly helps activate Leucine uptake. Insulin tells the muscle cell to send more system A amino acid transporters to the cell surface (22), which enhances the glutamine uptake. The more glutamine that is carried into the cell, the more cell will be able to import Leucine. Thus, the insulin signal has a strong effect on mTOR activation through direct (PI3K/akt) and indirect mechanisms.


Thus, it can be said that intense workouts force muscle tissues to conduct protein synthesis on a large scale, provided if the right nutrition is ensured at the right time. Now, it is a known fact that you need amino acids, cell volumization and insulin to ensure maximum activation of mTOR and GROW.

Protein Source:

30-50g of fast acting whey isolates or case in hydrolysates

Free-form Amino Acids:

Following are free-form amino acids:

· 5g leucine or 10g BCAAs

· 10-15g glutamine

· 5g glycine

Carb Source:

If you are looking to lose fat fast, glycine and glutamine will cause enough insulin release coupled with the fast acting proteins. For all other cases, 25-75g of medium to high GI carbs will increase insulin to promote amino acid transport and cell volumization.


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