Nutritional regulation of muscle protein synthesis with resistance exercise: strategies to enhance anabolism.
Maximize your muscle protein synthesis after weight training, bros. I’ll highlight for you a recent review, which the scientist nerds can read entirely for free here, from Dr. Stuart M. Phillips. I encourage you to take the time to read this one.
Introuction: When scientists talk about muscle protein synthesis they are referring to accruing muscle proteins in an overall net positive balance. That is to say, taking the most basic form of proteins, amino acids, and eventually creating structural muscle (aka hypertrophy). Normally, this is done by adding to already existing contractile machinery of the muscle cells. Researchers suggest that muscle protein synthesis (MPS for now on) is controlled by certain factors including dose, food source, and timing. Let’s see what Dr. Phillips has to say about each of these areas.
“The anabolic window” -Timing
It’s like the holy grail of muscle growth for bros. ”You can’t miss the window or you ruined the entire workout.” Well, that’s a bit exaggerated. Phillips states that, “It is now unequivocal that immediate post-exercise amino acid provision is an effective nutrition based strategy to enhance MPS above rates observed with exercise alone.” Early post-exercise ingestion of amino acids or protein comes from studies that showed that exercise induced increases in rates of MPS are greatest right after exercise; approximately 100-150% above basal rates. However, it may not be that big of a deal if you miss this window. If you look at the figure below, the increase in MPS is in fact greater after exercise but can remain elevated for up to 48 hours. Phillips suggests that consuming protein during these later times as well can be just as beneficial as ingesting protein directly after exercise.
More importantly, Philips discusses the importance of actual exercise intensity and how it relates to muscle failure. This is in lines with a study I touched upon in the past. Looking at yet again another figure below, you can see that groups that take resistance exercise to failure, regardless if they’re using heavy load and low volume, or a light load and high volume had an enhanced amino acid sensitivity to muscle protein synthesis. Let me say that again, IRREGARDLESS OF HOW MUCH WEIGHT YOU USE, as long as you are taking the muscle to failure, you will increase your rates of muscle protein synthesis more than loads not till failure.
Let it be noted that whey, egg albumin, soy, casein, and beef have all been shown scientifically to be able to stimulate MPS. However, the Philips group has shown in the past that whey and milk can increase MPS greater than soy products following resistance exercise (this could be due to differences in amino acid profiles and/or digestion kinetics). Why is whey fast-digesting and casein slow-digesting? Every one knows that or will tell you that but do they even have an explanation why? Phillips drops a knowledge bomb with one sentence, “Whey protein is acid soluble and is associated with a very rapid, large, but transient increase in postprandial amino acid availability, while casein coagulates and precipitates when exposed to stomach acid and the resultant dairy curd is slowly released from the stomach resulting in a much more moderate but sustained rise in plasma amino acids.” I love knowledge bombs.
It is still accepted that in young healthy individuals, approximately 20-25g (which corresponds to approximately 8-10g of essential amino acids) of a rapid digesting protein source (whey or milk) can help maximize stimulation of MPS after resistance exercise.
There you have it. Now, I’m off to eat some beef.