There is no cycle. If you are using HCG to augment your TRT regimen, you would run it full time just like your TRT. Although I have heard some guys say they do actually cycle it, but I think their reasons are mostly bullshit and not backed up by science.
So basically what I'm saying is if you are going to do a BLAST, there is no need to add HCG unless you are already using it as part of your TRT regimen. It's not like you are going to get "more shut down" on your blast than your TRT "cruise".