Madrid - Justin Gatlin, the 2004 Olympic 100m champion who served a four-year doping ban, said he feels like a rookie again as he tries to rebuild his career at the age of 29.
"The four years of sanctions have been more difficult from the psychological point of view," the US athlete told Spanish daily El Pais in an interview published Monday.
The ban "was tough because I was on top, I had it all", he said.
"But now I see things differently. I don't think I am better, I'm the same age as Tyson Gay and Asafa Powell, who are doing very well. I feel as if I am starting again, as a rookie. I feel my body still has much to give."
Gatlin's four-year drugs ban saw him plummet from sprinting's pinnacle to the athletics wilderness, but he has rebounded to make the US team for the 100m at the August 27-September 4 world championships in Daegu, South Korea.
Three months after equalling the world 100m record in 2006, he was suspended for four years after testing positive for testosterone.
That was considered his second doping offence, following a 2001 violation for a banned stimulant, resulting in a longer ban.
He has never admitted to knowingly using banned drugs, but he lost two appeals and failed in a legal battle to compete at the 2008 US Olympic trials for a chance to defend his Games gold in Beijing.
Since his return last year, he has been shunned by many of the sport's major meeting organisers but despite the apparent lack of top-notch competition, he made the US team for the Daegu worlds.
And on Saturday he edged Dwain Chambers in the 100m at a meeting in Madrid, clocking 10.10sec to the Briton's 10.13sec.
Gatlin said Jamaica's reigning world and Olympic double sprint champion Usain Bolt "is the most powerful sprinter with the most confidence, but at any moment he can show a weakness. Any runner can be beaten. I do not fear anyone".
He said France's 21-year-old European champion Christophe Lemaitre "has surprised many people. He is still young and very talented".
Asked if any white person could compete at the highest level in the sprints he replied, "I think the same happens with whites in swimming. Black people don't try because they think they can't be as good.
"It's the same with the white sprinters, they don't try because they feel intimidated. Lemaitre is very brave."