well steroids are only one of the many cocktail of drugs pro athletes use, I think you are being a bit blinkered if you just look for the after effects of muscle growth drugs :S....... the are so many options for guys to use, boosting endurance, boosting recovery times from hard training and so on... I dont think there is anyway to tell just by looking at someone whether they are doped or not.. It is a really hard and highly scientific and professional job to catch the pro drugs cheats, I think you are more likely to bust the infrastructure of doping rather than getting guys testing positive(aka, evan fields and peyton manning getting hgh delivered )...