It's not enough to just test athletes. The athletes themselves need to fight for their right to compete against clean athletes.

Something is swelling up among our athletes. Many of them are frustrated, everywhere in the world, and they are looking for a way out. Either they start doping themselves, or they give up the sport. Or else they stand up and demand that those who have the power to should change the system.

Education and prevention are not enough when there is a culture of fraud.

In order to expose a system though, you need whistleblowers.

The Olympics unite the world and inspire us to be a better version of ourselves. The competitions motivate the spectators, and the athletes' message is: You should have more confidence in your ability to achieve things, you should dream more.

In the old days, athletes got worked up about the strict rules - today they get worked up about these rules being ignored elsewhere.

I have never heard a doping offender say he felt good about doing it. Not a single one. Some athletes justify their actions by saying it enabled them to afford a bigger house or a better car. But they are never really happy. They know that they are not real winners.