The Waterford native says he understands that people looking from the outside can be suspicious of athletics
Thomas Barr admits he understands the suspicion around doping in athletics and insists that he's a clean athlete after a fourth placed finish in the final of the 400m hurdles.
Barr set a national record with his time of 47.97 and says that anti-doping measures have been extremely thorough in the lead up to the Olympics.
"I've probably been tested 11 or 12 times," he said. "I know I'm clean and that the Irish anti-doping system is one of the best in the world. It's just a pity that it's really come out in recent years that not every country is like that.
"It is very disheartening because there were two Kenyans and a Turkish guy that beat me in the final and their countries have had a lot of controversy over them.
"But look, you can only race at the end of the day what's on the track. They're innocent until proven guilty. There's as much chance of them being clean as there is being unclean. If it does come through that at the end of the day that something does come through, all well and good and I'll be upgraded."
He explained that progress can look deceiving over the course of a year or a season and used an anecdote to explain the suspicion people have of suspected dopers.
"I often doubt... I come back to a story. I was in Hong Kong last year waiting to get into the World Championships and Brian Greegan was going through people's progression on the IAAF or one of these sites and say for the 100m it was 12, 11, 10, 9 [seconds] over three years or over a season. And we thought 'Oh there's definitely something going on there.'
"Reading through it was like 55, 56, 50., for hurdles, 49 and again I thought something was going on there. That was my own progression about five years ago!
"I don't want to be placing red flags on myself but that's just the way it is. There is always going to be doubt in people's minds over what is going on.
"I know I'm clean, anyone who has been with me over the years knows I'm clean.
"Fresh legs seems to bode well for me. Spark suspicion or not, I went out there and I did what I did today. I know myself I've done it."