Double breaststroke world record holder Adam Peaty believes his best is still to come.
The 20-year-old became the first man to swim the 100m breaststroke inside 58 seconds when he set a time of 57.92 seconds at the British Swimming Championships in April,
That came eight months after breaking the 50m breaststroke record.
"There are lots of areas I can improve to get every millimetre out of myself," Peaty told BBC East Midlands Today.
"I am more pleased to be the first person to go under 58 seconds. I never thought I would get anywhere near it.
"It boosted my confidence massively knowing I can go that fast.
"It's a great position to be in, but it's now about re-focusing and re-motivating to see what I can get."
As well as breaking the 50m breaststroke world record at European Championships last August, City of Derby swimmer Peaty also won European and Commonwealth titles during 2014.
The 100m record beat the previous mark of 58.46 set by South Africa's Cameron van der Burgh at the London 2012 Olympics.
Peaty said the World Championships this summer, and the Rio Olympics in 2016, are now on his radar.
"I'm confident - I've been the fastest in 50 and 100 so far - but that doesn't mean I will get gold, silver or bronze," he added.
"It's all about grounding myself now, staying level-headed and ensuring that I get the best possible swim out there."
The Staffordshire-born swimmer made his mark in spectacular fashion last summer, winning two gold medals at the Commonwealth Games in Glasgow and four at Berlin's European Championships, where he bettered van der Burgh's 50m breaststroke world record.