No study needs to show if kids use drugs when they participate in a sport. If you're caught using drugs, drinking alcohol, anything like that, you're off the team. That's their incentive to not do anything like that. At my school at least, it seems lots and lots of people get drunk pretty frequently, and lots do marijuana. There's an area just off campus where kids go to smoke during school (which I think is handicapped, frankly) but the school I go to is one of the top high schools in Washington in terms of college acceptance and whatnot. Two years ago, the graduating senior class had a 92% acceptance rate in college. The other 7% was gap-year students, traveling abroad, working to pay for college, etc...
It. Is. A. Stereotype. And often times, the people who are getting C's and the such are the students that don't function to perform higher than that. There are lots of kids like that, and they find brilliance in other areas. At least that's the case with kids I know. Yeah, they smoke marijuana, yeah they don't get straight A's in school, but some of them make the coolest music, play some instrument extremely well, some invent things, it's just the way they work. You can argue all you want, even with the proof, but your "study" said itself it's not a national representation. That's numbers from Connecticut students.