good post in general f450, i agree with most of what youre saying, but i have to disagree on some of the points too.
some people will call me out or disagree with what follows but its all based on my personal extensive research on that topic (i consider insulin sensitivity one of the - if not THE most important thing regarding body composition/bodybuilding in general and i spend a lot of time reading into that specifically).
1. insulin does not work via a negative feedback loop. you cant shut down your bodys own insulin production via exogenous insulin use. well, you can, for the time its active. but not long term.
you can become resistant to insulin if you ABuse it or use long acting insulin (that actually makes you insulin resistant within DAYS). doesnt happen with rapid insulin use, especially not pre workout imo.
2. visceral fat accumulation CAN be caused by insulin ABuse. agree on that, but abuse means extremely high doses multiple times a day, often combined with a basal (long acting) insulin aswell.
theres hard scientific evidence that long acting insulin makes you insulin resistant (=essentially diabetic) within days of use. just like GH (see point 3.)
a bodybuilder should NEVER touch anything else but rapid insulin. i would also strongly advice only using it at the muscle crucial time of the day (=pre workout).
3. whats much worse than insulin abuse is GH abuse.
GH makes you insulin resistant, just like exogenous basal insulin. high doses of GH are MUCH more worse insulin though.
GH is responsible for high fasting blood sugar levels and insulin resistance.
continuously high blood sugar is the culprit for EVERYTHING you describe, its usually NOT caused by insulin abuse (and certainly not from 20-30 units a day).
GH abuse is what causes palumboism, nerve damage, the guts on todays pros, the diabetic look.
GH abuse is much worse than insulin abuse in that regard.
i can only speak for myself here, but after 14 weeks of continuous insulin use (15 to 20iu pre workout, 5 times a week) my fasting blood sugar was still in the 70s or low 80s every single morning.
it didnt budge AT ALL.
thats zero sign of insulin resistance/insensitivity. people claim you can only use insulin for 6 weeks and then HAVE to cycle off. thats just bullshit.
maybe im just genetically lucky in that regard, but id worry MUCH more about using high doses of GH than high doses of insulin when it comes to insulin sensitivity / resistance.