This originally came as quite a surprise, because insulin is a potent activator of protein synthesis. Insulin activates mTOR by way of PI3K/akt signaling, which is parallel to the pathways used by amino acids and mechanical stress to activate mTOR.
Taking all this work together, it's safe to say that while insulin doesn't appear to increase exercise-induced protein synthesis, it may act to "hold the throttle open longer" for the protein synthetic machinery after a workout.
Protein synthesis occurs in the cytoplasm by the ribosomes.
The post-workout meal is the most important for amping up protein synthesis after a workout. Muscle cells are primed for protein synthesis in the hours after training, but only if the right nutrition is there.
Muscle Protein Synthesis Gets You Bigger and Stronger ..
Importantly, activation of protein synthesis in the seems to ultimately determine how well we respond to training in the . What this means is that not only are workouts needed to maximally activate protein synthesis, but the right nutrition needs to be there at precisely the right time for this to happen.
What do genes do?: 5 Where does transcription occur …
There's been considerable research on exactly what type of nutrition is needed to maximally activate protein synthesis. While we'll discuss specifics later, it's important to know that only the essential amino acids (EAAs) have been shown to activate protein synthesis, with in particular being the most important for turning on the protein synthesis machinery.
5 Where does transcription occur in the cell
Think of it like this – if mTOR is like the gas-pedal for protein synthesis, then AMPK is the brakes. While it's been shown that pre-workout nutrition doesn't improve the post-workout burst in protein synthesis better than exercise alone, pre-workout amino acid intake does blunt AMPK mediated inhibition of mTOR.
Protein synthesis :: DNA from the Beginning
It's also clear from the literature that carbs aren't needed to activate protein synthesis after training, but there are other reasons to include carbs, which we'll get into later.
DNA Replication and Protein Synthesis - Biology Is Fun
Proteins act synergistically with weight training to stimulate protein synthesis, but just as there's an upper limit to how much exercise we can productively recover from, there also appears to be an upper limit to how much protein we can eat to max out protein synthesis.