Well for the effectiveness of drug testing you should talk about the limitations and benefits of testing. Perhaps the myth of a level playing field you could talk about access to technology? E.g. The swimming LZR suit broke 46 WR at the 09 swimming championship due to its streamlined fit and frictionless materials (any other characteristics of the suit). Then you could say that some countries are disadvantaged due to these suits because of unequal access to these suits and financially the countries cant afford them, and thus the playin field isnt always even?