Could the muscle prefer muscle protein synthesis over muscle breakdown in case of a high ingestion of protein and amino acids, and can this be - ?
When a lot of AA or protein is ingested after exercise could the muscle choose to store the AA's rather than focus on the break down and can this have a negative effect on the replacement of certain proteins that are affected by exercise?
hello peter you can study These articles for find your answer.
Article Whole-body protein turnover response to short-term high-prot...
Article Effects of skeletal muscle energy availability on protein tu...
Article The role of leucine and its metabolites in protein and energ...
Article Effects of dietary L-arginine levels on small intestine prot...
Article Protein turnover, amino acid requirements and recommendation...
Article Daytime pattern of post-exercise protein intake affects whol...
Article Postexercise Whole-Body Protein Turnover Response to Three L...
Hi Peter, there is no evidence to my knowledge of this scenario happening. Amino acids per se do not really impact protein breakdown. Some insulinogenic amino acids such as leucine may stimulate slight insulin secretion which may in turn impact breakdown but this is marginal and non significant. Therefore, amino acids stimulate the synthetic response (Greenhaff et al 2008 APEM Dissociation etc.....). AA intake after exercise increases the storage of aa's hence the increase in FSR. In some seminal work by Phillips et al 1997, the authors showed that after resistance exercise, breakdown was greater than synthesis. The proteasomal system works by tagging damaged proteins for breakdown and this is aa independent. Therefore it seems unlikely that excess protein/aa intake will negatively effect the replacement of certain proteins that are affected by exercise.
In the lastest article of Phillips I seem to note that ingesting 70 g of whey in stead of 40 g of whey would lead to a decrease of MPB, and this could conflict with muscle recovery/repair and such. So it was adviced not to ingest that high amount. It comes close to what I was proposing. I must say I am no expertise of course, and that the article mentioned that MPB in general was less researched. Of course it depends if MPB is whole body, or muscle specific. What do you think?
Thanks and regard!
Hi Peter, please share the citation of the specific paper you mention above so that I can get further clarity on your point regarding " and this could conflict with muscle recovery/repair and such ". Indeed MPB is less researched as most research focuses on half the equation of balance, namely MPS. MPB is muscle protein breakdown otherwise it is stated as whole body protein balance.
please see the actual paper addressing this point Article The anabolic response to a meal containing different amounts...
You will see that breakdown was attenuated at the whole body level with 70g but breakdown was not actually measured at the muscle specific level. This is important to consider. In fact the gut turns over about 10x quicker than muscle so one could presume that a small fraction of the balance is muscle specific (also discussed in the review you shared)
- Badges
- Science topic
- Similar topics
- Computer Science
- Program