From a competition standpoint, it should ALL be against the rules in the interests of evening out the playing field (those who dont use are at a disadvantage, which is against the spirit of the games IMO). With the NFL specifically, I can see legit uses for HGH or HGH-like products (Ray Lewis actually uses some kind of Deer Antler shit, it's a spray) because of the significant wear and tear on their bodies - but at the same time, if no one was using any performance enhancing drugs the players would likely be less strong and fast which that in and of itself would reduce injuries. I kind of dont mind the NFL's policy, where it's pretty heavily regulated and only certain drugs are approved and are only administered by team doctors, etc(like those shots players get before games to play through minor - but painful - injuries). IDK I'm kind of on the fence, because my first instinct is NO but like I said I can see why NFL players use.
Baseball though? Fuck them, if they can play into their 40's naturally they dont need any kind of help. The average NFL careeer is three years so...