The answer is quite simple. It is not against the rules. The World Anti-Doping Agency (WADA) has no prohibitions whatsoever on performance enhancement surgeries. They are all permitted.
It seems to me that elective surgery in sports threatens the integrity of records in sports no less that the use of anabolic steroids in sports. But for some reason, most people who concern themselves with such are only concerned about anabolic steroids and other performance enhancing drugs. It is baffling.
So for now, it is perfectly acceptable for athletes to surgically implant nanotechnological devices to elicit certain performance enhancing physiological responses. Pharmaceutically-enhanced performance is bad! Surgically-enhanced performance is good!
The British bioethicist, Andy Miah, explains that sports are “technologically enabled practises.” He has some interestingon this issue:
Miah believes there is now a new frontier in sporting technology, driven by the convergence of nanotechnology, biotechnology, information technology and cognitive science…
Miah, who believes genetic manipulation of athletes is not necessarily a bad thing, says the march of technology is throwing up some crucial philosophical questions.
“The development of biotechnology, stem cell research, cloning technology and the like has provoked a kind of moral encounter with what it means to be human and what technology might be doing to alter that.
“If we can develop devices that make it difficult to say these are external to the body, if they’re implantable into the body then it becomes much harder to say that they are artificial.”