Cortisol, androgen and gene expression

[Scott Stevenson]

Hi Scott,

I recall hearing you discuss how it may be crucial for a bodybuilder looking to maximise muscle gain to prevent cortisol from raising too high even during a training bout. I believe your rationale (or at least part of it) was due to cortisol being a steroid hormone that binds to the androgen receptor, so even when cortisol levels are reduced (via diet, sleep or whatever) their catabolic effects may still continue to occur?

Please correct me if I have this completely wrong. Do you have any papers in your library that you could point me towards to educate myself further on the subject? I have been having a dig around google scholar, but feel like I would benefit from a nudge in the right direction.

Thanks !

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