I love these arguments where kids try to "prove" that today's athletes (2 footed or 4 footed) are "better" than the legends of yesteryear. Such a thing can never, ever be truly proven to a certainty. All that has improved, as has been stated, is nutrition, training methods, etc. But the basic genetic material? No. So of course it begs the question what would Jesse Owens or whoever do w/today's technology? Again, impossible to state, but if you're a betting man (& I am)...
Damn sure I bet Jesse Owens would smoke those "routine High School kids" all day every day till he got bored of doing it.