Cortisol, androgen and gene expression

[Stewilliams]

Hey Bud!

So, you've got the main pieces of my perspective in there, but just a big jumbled.

(Thanks for posting this on the open forum, too, BTW.)

Main issue is cortisol binding to it's own receptor, initiating protein catabolism (that proceeds slowly over time, as the actions of steroid hormones do via the classical mechanism). An acute elevation of cortisol resulting it it binding to it's receptor means setting into motion longer acting (gene expression-related) mechanisms of muscle protein breakdown (and other things like upregulating PEPCK in the liver for the purpose of glyconeogenesis).

Here's the paper that I typically refer to (I've covered this in a few articles, now I think and in my BYOBBCoach book.)

1. Tarpenning KM, Wiswell RA, Hawkins SA, and Marcell TJ. Influence of weight training exercise and modification of hormonal response on skeletal muscle growth. J Sci Med Sport 4: 431-446, 2001.

Related articles from some of the same authors:
1. Bird SP, Tarpenning KM, and Marino FE. Independent and combined effects of liquid carbohydrate/essential amino acid ingestion on hormonal and muscular adaptations following resistance training in untrained men. Eur J Appl Physiol 97: 225-238, 2006. http://www.ncbi.nlm.nih.gov/entrez/query...s=16456674
2. Bird SP, Tarpenning KM, and Marino FE. Effects of liquid carbohydrate/essential amino acid ingestion on acute hormonal response during a single bout of resistance exercise in untrained men. Nutrition 22: 367-375, 2006. http://www.ncbi.nlm.nih.gov/entrez/query...s=16472979
3. Bird SP, Tarpenning KM, and Marino FE. Liquid carbohydrate/essential amino acid ingestion during a short-term bout of resistance exercise suppresses myofibrillar protein degradation. Metabolism 55: 570-577, 2006. http://www.ncbi.nlm.nih.gov/entrez/query...s=16631431


Here's figure from the Tarpenning et al. study showing the inverse correlation between cortisol (reduced in this study by consuming carbohydrate as an intra-workout).

That's a high correlation, FWIW.



-S

Thanks Scott, this has created a few no questions for me so I'll continue doing some digging!

No need to thank me for posting here, I would never consider posting such a question elsewhere (in a private message for example )

I'm quite familiar with the above studies, but am surprised that there hasn't been any significant follow up research. I know quite a few sports nutritionists who work in professional sport and one of them is head of nutrition for a national football (soccer) team. All of them implement strategies for their athlete's to intake carbohydrates during competition and training, but do it purely from a fuelling perspective (which is most important). I've asked them about the recovery and/or adaptation potential of their methods and they dismissed them and said it's not something they have considered and have never seen any evidence for!