Laura Muir fired a warning to her rivals and insisted she is more dangerous than ever.
The 29-year-old opens her fifth World Championships campaign in the 1500m heats in Eugene on Friday.
Muir is targeting a first medal at the World Championships having finished fourth in London five years ago and fifth in Doha in 2019.
She battled foot and calf injuries in the build-up to her last two championships but, after last summer’s 1500m Olympic silver medal, feels she has established herself.
“We’ve done it now and that takes the pressure off a bit and if anything it makes me more dangerous,” said the Scot, who finished fifth in Beijing in 2015 and made the 800m semi-finals two years earlier.
“I don’t have that weight on my shoulders. I can go out there and be more relaxed. When I’m relaxed I run better.
“It’s nice to go in and not have that pressure on myself to know you have to get this medal or we’ve never won a global outdoor medal. I don’t have to prove myself.
“In Doha it was the second fastest time I had ever run, in a championship final as well. It was incredibly frustrating to run one of the fastest times ever in history and I wasn’t even fourth, I was fifth.
“That was off the back of an injury so what could I have done if I’d not had an injury? That was the most significant one I’d had in my career.
“If anything it highlighted a couple of areas I was weak in and, off the back of that, we worked really hard to make those weakness a lot stronger. I don’t know if I would have been as fast, strong and as robust for the Olympics had it not been for the injury.
“It was a bitter pill to swallow but I’m physically fitter and stronger now than I would have been.
“Hopefully this year I can add the elusive World Championships medal, fifth time lucky.”
Yet, Muir will still need to overcome Kenya’s Faith Kipyegon, who beat her to Olympic gold in Japan last year and has not lost since Tokyo.
“Man or woman, she’s the best 1500m runner this world has ever seen,” said Muir. “She’s been in every single world finals since 2015, maybe 2013, and almost every time has won a medal, as well as back-to-back Olympics and having a child.
“She is an amazing, amazing athlete and it’s an honour to run alongside her even though she’s very, very fast.”
The Championships in Oregon start a frantic summer for Muir who is also due to compete at the Commonwealth Games for Scotland before the European Championships in Munich in August.
“Even just a medal at one championships is huge,” said Muir, looking to defend her 1500m European title from 2018. “Who knows, but to medal at all three within a short space of time, that would be crazy. That would be fantastic.
“That’s what I set out at the start of the year – to run in all championships and win a medal at all three.
“I’ve just got to try and not get too carried away with thinking about that just now and trying to focus on one championship at a time.”
Muir is joined in the heats by Katie Snowden and Melissa Courtney-Bryant while Reece Prescod and Zharnel Hughes run in the 100m heats.
Nick Miller (hammer) and Sophie McKinna (shot put) compete while Holly Bradshaw is aiming to add to her Olympic bronze when she begins her pole vault qualification.
The 4x400m mixed relay team also have the chance to win Great Britain’s first medal with the heats and the final on the opening day at Hayward Field.