Athletics chief Sebastian Coe admitted Thursday that his drug scandal-tainted sport faced a grueling battle to regain trust as it embarks on the road to recovery at the World Indoor Championships.

Coe said he had no idea how long it would take to win back fans disgusted by months of lurid headlines about drugs and corruption that followed last year’s bombshell World Anti-Doping Agency (WADA) report into Russian doping.

The beleaguered International Association of Athletics Federations (IAAF) president has faced mounting calls to step down over his handling of the worst crisis in track and field history, with US distance runner Alysia Montano and track legend Carl Lewis both calling his leadership into question.

Responding to the criticism on Thursday, Coe said he was confident changes being implemented by the IAAF would address concerns about the sport.

“The changes we will have made by the end of this year will self-evidently answer and deal with many of those challenges that we’ve got,” Coe said.

“But we’re not going to return to trust overnight. You don’t stick 10 dollars in a slot machine and suddenly trust appears in the tray. This will take a long time. Clean athletes have got a big responsibility here as well.”

Coe admitted however that he did not know how long it would take for athletics to rise from its sick bed.

“I don’t know. We could have this debate here for a couple of hours. We can’t demand trust. It’s not going to just return because we’ve got reforms in place,” Coe said.

“But what I do know is that unless we start from where we are at the moment it’s unlikely to happen.”

Although a fresh doping crisis in world sport has erupted since the start of the year, with around 100 positive tests of the newly banned endurance-booster meldonium, Coe said he believed fans would be able to trust the performances at Portland’s Oregon Convention Center when the championships get under way later Thursday with the men’s and women’s pole vault.

Russian athletes have been banned from the championships following the WADA report and could even be thrown out of the Olympics.

Ukraine on Thursday said 800-metre runner Natalya Lupu would not compete in Portland for also using meldonium.

“This is an important staging post in the season and it’s an important part of our road to recovery,” Coe said.

“We’re back in competition which is really important for our sport.”

Coe, meanwhile, said he was concerned that the meldonium scandal could be part of a wider problem of athletes abusing prescription drugs for performance-enhancing purposes.

“We need to look very closely at that,” Coe told AFP.

“But the bigger challenge of course is around the use of prescription drugs if there isn’t an underlying medical condition.

“That’s not just a medical issue that’s clearly a very big ethical issue and we need to meet that challenge.”

Marshalling Logo for Achilles Tendinopathy Coe Athletics faces long battle to regain trust says Coe marshalling room