Thesis: Athletes who use any type of biotechnology give themselves an unfair advantage and disrupt the sense of fair play, and they should be banned from competition.
Athletic achievement nowadays increasingly results from biological and high-tech intervention rather than strictly from hard work.
There is a difference between the use of state-of-the-art equipment and drugs and the modification of the body itself.
If the rules that guarantee an even playing field are violated, competitors and spectators alike are deprived of a sound basis of comparison on which to judge athletic effort and accomplishment.
If we let athletes alter their bodies through biotechnology, we might as well dispense with the human element altogether.