Ok, I checked the WADA anti-doping Code (very briefly).
The definition of "doping" in there is "violation of anti-doping rules".
Then the rules are defined.
Basically, there is a list of prohibited stuff, which also includes the problematic "what is not addressed with this list is prohibited".
The document itself is sufficiently complicated (also with exceptions) so that contadictory conditions can happen (as with for example therapeutic exemptions), the wording of prohibiting anything not approved by governing bodies for therapeutic use (jurisdictional issues), and of course a large (and growing) potential for unknowingly violating the rules by using products in general use.
The "all methods not approved" is also wery weak; what is a novel method, a variation of established method, an approved method used with different parameters, combinations, etc.
I'm sure (as is the case in the field of patent law, for example) there is sufficient maneouvering space to achieve what you want with enough resources (and lawyers), while at the same time inadvertendly banning people for eating something from a supermarket.
Anyway, I stand by the general questions: how to innovate and adhere to ever more complicated rules? Do the materials used on the skin, on the bycicle, in the helmets etc. pass the above rules? What is the point of preventing athletes from using stuff other people can (and do) use everyday? What is "level playing field" and the "spirit of sport"?