Good read from DeVany on Muscle Glycogen and Gene Expression, fits into the whole PWO arguement (or lack there of) for fat loss and muscle gain.
This was on my desk and I didnít get to it during my blitz. I have mentioned gene expression research and pointed out that some kind of local and broader signaling is telling the muscle genes what to do ó how much to grow and what kind of fibers to make.
1. As I previously reported we know that a low muscle glycogen state signals muscle growth. So, low muscle glycogen promotes muscle growth, completely contrary to conventional thinking.
2. An acid environment in the muscle signals the production of FT muscle fibers. An oxygen laden environment signals ST genes. Anaerobic work produces lactic acid which is the gene signal.
3. The FT fibers are voracious fat burners, a little known secret that is still being unraveled. Perhaps fat fuels the restoration of depleted glycogen and phosphates in FT fibers. ST fibers use fat directly, FT seem to use it indirectly in some obscure way. I have posts on this too.
Which brings us to the research I had intended to mention in the blitz. There are genes in the muscle called atrogenes that produce muscle atrophy. Their expression is enhanced by high muscle glycogen. Low glycogen down regulates their expression. In short, high glycogen promotes muscle atrophy or wasting away.
A hard work out levels this difference, but as the muscle recooperates it will go to a low glycogen state for a period of time. During this recovery state atrogenes are turned down.
Thus, a low glycogen state is anabolic in at least two respects: atrogenes are turned down and growth promoting genes are turned up. Other changes are induced as well by low carb diets. Genes that encode for glucose utilization (GLUT 4 and glycogenin among other factors) are turned down and those that promote fat burning are turned up. I think you can see why I am not in a hurry to replenish muscle glycogen after a work out. Or to ingest simple carbs. These factors explain why SuperMike continued to grow muscle even while fasting.