My opinion:
Everyone is "on". Everyone pushes the boundaries of what is legal.
You have someone who has trained 6 days a week for 4 years for one chance to win gold, often within a field where thousandths of a second determine success or self flagellating failure.
These people did not just wake up one morning a few months back and think, hey, I want to go to the olympics. These people are driven, type A alpha personalities. They train until they puke (unless they play one of those phaggotty sports like golf), get up at 4am to train in rain, cold, frost, heat, humidity and whatever else can be thrown at them. They are backed by a team of trainers, coaches and therapists. They have financial backing from governments and, in many cases, private corporations. If they fail, they may even face some sort of social or political backlash (hello PKR athletes). Their personal life is squished in around training and recovery. They give up all sorts of "normal" luxuries such as a social life, certain foods and relaxation time. All for those split seconds at the finish line.
http://www.dailymail.co.uk/video/ne...ble-moment-Shaunae-Miller-dives-win-gold.html
Now.
You can get that extra split second, or extra kilo, or extra endurance by taking a legal substance. Do you take it? Of course.
But what if the legal substance is banned during comps? Well, still yes.
Now what if you know that if you sneak it in during a comp it will get you across the line?
No. I'm 100% natty. Right?
What if its an "illegal" substance?
What if you are struggling with recovery, an injury or just not improving as you should? Remember, you are not El Stiffy who does not compete and can have a day off any time he wants. You are still getting up at 4am and getting into bed at 8pm and doing all that other stuff.
Do you dope? Probably not if you are doing fine. What if you're not doing fine? Mebbe some peptides? Some fast acting stuff with quick clearance times? A bit of blood boosting or oxygen therapy? All for the greater good?
I'm pretty sure that given the opportunity and means, they would all be doing something at least "rule bendy".