I don't think there are studies in atheletes or BB's, but the doctors at the Anti Againg Group (the HRT doctors I use) swear by 5 on and 2 off and I know price is no object. They will let me do two (2) of the 2.8 IU shots a day using Genotropin Mini-Quicks for 5 out of 7 days a week (5 on / 2 off). But they won't let me do even half that 7 days a week.
There was as study looking at natural GH restoration in children who were GH-deficient and given exogenous GH. The EoD group resumed their own production as adults, the 5 on / 2 off group recovered second-quickest and the ED group had the most problems. Again, I know that's not atheletes/BB's tho. I'll look for the study.
We need more clinical studies from old farts like me to figure out how hard exogenous GH shuts you down if you discontinue it.