Actually a good friend of mine does this between his cycles and the guy is much bigger than me. He has been up to 230lbs. at 5'6. Anyways when speaking to most people that have used gh, they tell me that the most beneficial thing is not losing any gains between cycles, which is my main goal not to lose any size between cycles this year.
As far as hgh down regulating igf-1 receptors and that affecting IGF-1 Long r3 intake, I will say it sounds doubtful. When using testosterone one of the primary ways it increases muscle mass is by increasing IGF levels.
1: J Clin Endocrinol Metab 1997 Nov;82(11):3710-9 Related Articles, Links
High dose testosterone treatment also increased serum insulin-like growth factor I concentrations by 21% and 34% over those during the eugonadal and hypogonadal states, respectively (P < 0.01).
Which is why I beleive high doses of test are recommended when using hgh since the increased IGF levels caused by testosterone effect proliferation of satellite cells, wouldn't using IGF itself have a similar effect as using high levels of test for that reason.
1: J Appl Physiol 2000 Oct;89(4):1365-79 Related Articles, Links
IGF-I restores satellite cell proliferative potential in immobilized old skeletal muscle.
Chakravarthy MV, Davis BS, Booth FW.
Department of Integrative Biology, University of Texas Medical School, Houston, Texas 77030, USA.
One of the key factors responsible for the age-associated reduction in muscle mass may be that
satellite cell proliferation potential (number of doublings contained within each cell) could become rate limiting to old muscle regrowth. No studies have tested whether repeated cycles of atrophy-regrowth in aged animals deplete the remaining capacity of satellite cells to replicate or what measures can be taken to prevent this from happening. We hypothesized that there would be a pronounced loss of satellite cell proliferative potential in gastrocnemius muscles of aged rats (25- to 30-mo-old FBN rats) subjected to three cycles of atrophy by hindlimb immobilization (plaster casts) with intervening recovery periods. Our results indicated that there was a significant loss in gastrocnemius muscle mass and in the proliferative potential of the resident satellite cells after just one bout of immobilization. Neither the muscle mass nor the satellite cell proliferation potential recovered from their atrophied values after either the first 3-wk or later 9-wk recovery period.
Remarkably, application of insulin-like growth factor I onto the atrophied gastrocnemius muscle for an additional 2 wk after this 9-wk recovery period rescued approximately 46% of the lost muscle mass and dramatically increased proliferation potential of the satellite cells from this muscle.
PMID: 11007571 [PubMed - indexed for MEDLINE]
So I think that high doses of testosterone are recommend for use with hgh since the increased igf-1 levels increase satillate cell proliferation which increases muscle mass and that substituting igf-1 for test would have a similar if not greater effect and help me retain or even gain muscle during "off" periods. I might be competely off here though as I'm not as smart as basskiller.
