"If T3, ECA and Clen cause insulin resistance that means they should all be avoided when you do a carbup right...
Should I use chromium during my carb up ?"
Definately use insulin sensitizers and insulin mimickers during carb up, such as chromium, vanadyl, ALA, metformin, etc. They will increase the ability of the body to utilize glucose and prevent its coversion to triglycerides.