Give up on the hormonal motivation...such changes are 1) quite small, and 2) irrelevant.

ETA: The hormone myth appears to be largely based upon the work of Bill Kramer, who has never actually measured muscle protein synthesis in his studies - only changes in hormone concentration (which is trivial to do).

ETA2: Here is a review by Stu Phillips (one of the post-docs in the lab during my Galvetraz...err, Galveston days) that delves into the evidence:

https://www.ncbi.nlm.nih.gov/pubmed/20959702