Some mods good, some mods bad.
It almost seems as if we're indoctrinated by North American culture to not enhance ourselves (the blizzards of spam to the contrary) in some way, shape, or form but still be told to do whatever we can to make sure that we get ahead. It's safe to say that we've grown up in a time when we can't remember hearing about at least one star athlete being suspended from a league because they tested positive for anabolic steroid use (be careful searching on that term, there are a couple of dodgy SEO sites in the top twenty) to build up muscle mass. It's a far cry from sayin' your prayers and eatin' your vitamins every morning, but it still always struck me as being a weirdly conflicted message. A couple of weeks back, H+ Magazine ran an article on just that debate - some enhancements are good and yet some are bad for arbitrary reasons. The aforementioned synthetic male hormones are right out, and yet it's possible to have laser eye surgery performed multiple times to gain a precision of vision that most of us can only dream of (average is 20/20, meaning that you can see something twenty feet away that the hypothetical average human eye can see at 20 feet). But that's okay.
The hormone erythropoietin, secreted by the kidneys to regulate the number of red blood cells manufactured by bone marrow indirectly regulates how efficiently your muscles operate. A higher concentration of erythrocytes in the blood means that oxygen may be exchanged for carbon dioxide from the muscles more readily, leading to increased performance. Originally blood doping required autologous transfusions prepared weeks or months in advance but later the availability of synthetic erythropoietin meant that you didn't have to tap a vein to get an edge. Both practices are verboten in sports these days but lowering the concentration of oxygen in the air while you sleep (hypobaria) isn't. One guesses that this distinction comes from not wanting to penalize people who live at high elevations when they're not competing; a lower oxygen content in the air leads the body to produce larger amounts of the hormone. Even nootropic drugs are beginning to come under fire: several universities in the United Kingdom are beginning to consider whether or not they should start testing students for use of cognitive enhancement compounds to eke out a few more points on the curve but they're probably not yet cognizant of cognitive training techniques (which I maintain that they should start teaching in schools at a young age).
It's not easy to sort out what's going on. On one side of the bench, all of us are being pushed to excel at whatever it is that we do starting at a very young age. We're all urged to earn top marks in school so that we can get scholarships and go to the best schools. This drops off a bit in college but the current is still present. Grad school is no less than a trip through the underworld in which the rough bits of your psyche are ground away (or at least filed down) and even more information is packed into your head. Sports, like grad school, are a sink or swim proposition: play at the top of your form every time, all the time, or be forgotten as you sit on the bench. At some point everyone hits their limits; we all have them, whether or not we wish to admit it. Call it genetic potential, call it more neurons spontaneously dying in one region of the brain rather than another, call it one of the fifty-plus things that They say will massacre neurons en masse (from drinking alcohol to shaking your head too much (no, I'm not kidding (though you'll find dozens upon dozens of mirrors of that one page all over the place, which makes me mistrust it a little (more parenthesis than LISP! FTW!)))), call it having slightly less myoglobin in your muscles than the next lifeform in line... like it or not, enhancing drugs and techniques are what allow us to transcend those limitations inherent in our bodies. At some point the powers that be are going to have to make a decision: will methods to upgrade the body's functionality be allowed in $field_of_activity, will that field need to split to accommodate both the enhanced and the unenhanced (which seems likely to be a sports-related decision), or will They simply give up on trying to police how people train in their particular field and let the chips fall where they may?