Two of British athletics' brightest young talents have denied the sport is in crisis after a winter of global headlines about doping.
Allegations about systematic doping in Russia made by a German documentary in December were followed by news of a long ban for top US coach Jon Drummond.
But sprint pair Dina Asher-Smith and Richard Kilty said they were proof that athletes could win clean.
"[Doping] is disgusting, I have to work really, really hard," Asher-Smith said.
"And I know all the British girls are working really hard, so to paint them with the same brush is quite unfair.
"It's unfair to all the athletes who work really hard to say the sport's in a crisis."
Kilty agreed with his 19-year-old team-mate that it was best to concentrate solely on your own performance when lining up to race, as any thoughts about who may or may not be cheating would only be a distraction.
But the 25-year-old world and European indoor champion over 60m said there was a "shadow" over the sport.
"I race against convicted dopers at almost every Diamond League meeting or major championships and it's not nice or fair," Kilty said.
"But the best thing you can do is go out there and beat those guys, knowing you can have full pride in doing it clean."
The two Olympic hopefuls were speaking at an event staged by UK Sport to mark 500 days until the start of next year's Games in Rio de Janeiro.
As well as distributing lottery and public funding to Olympic and Paralympic athletes, UK Sport is also responsible for bringing major events to these shores, a challenge it is meeting with impressive results.
Between now and the start of the Rio Olympics, the UK is staging 29 world or European-level events across 20 different sports, from sailing's World Cup in Weymouth in June, to the European Eventing Championships in Perthshire in September.
These events are estimated to bring in more than £37m in economic benefits to their host regions and there are also 95 qualification places up for grabs for Rio 2016.
Kilty, who is now training with 1992 Olympic champion Linford Christie, missed out on London 2012 when he was controversially left out of the squad despite having met the qualification standard in the 200m.
But the 'Teesside Tornado' has made rapid progress since then, first winning a surprise gold medal in the 60m at the 2014 World Indoor Championships, and then backing that up with European gold over the same distance earlier this month.
"The speeds I'm running at 60m mean I should be running under 10 [seconds for 100m], so if I don't do it this year something will have gone wrong," said Kilty, who will next compete for Great Britain at the World Relay Championships in the Bahamas in May, before focusing on qualifying for August's World Championships in Beijing.
Asher-Smith was too young to compete at London 2012 - although she was in the Olympic Stadium on Super Saturday when Jessica Ennis-Hill, Greg Rutherford and Mo Farah all won gold in the space of 46 minutes.
Then she was carrying the boxes the athletes put their warm-up kit in - but now she is firmly on track for a spot in Rio in three events: 100m, 200m and 4x100m.
The Kent-born athlete became female sprinting's fastest teenager over 60m a fortnight ago, a performance that suggests the world junior 100m champion should make a smooth transition into the senior ranks.