Olympic champion Adam Peaty believes defending his title in Tokyo will be "10 times harder" than winning in Rio as the hunter becomes the hunted.
The 24-year-old has only improved since winning gold in the 100m breaststroke in 2016, and in August broke his own world record with a time of 57.10.
But while that makes him the favourite 15 months out from the Tokyo Games, Peaty believes the heat is on.
"In 2016, I was pretty much the hunter, now I'm the hunted," Peaty said. "Which is a very accurate way to put it. Everyone's out for my title. I don't mind that, it keeps me on my toes.
"Tokyo, it's going to be a very fast final, it's going to be a very fast competition, but for me I just stay chill, do what I do, and that's it really. I don't see any reason to over-complicate it.
"Winning it once is hard, but winning it a second time round, because of all the pressure and all the media and everything around that, is probably 10 times harder.
"But again that's what we do, we're athletes, we rise to the challenge and that's it."
Peaty's latest world record came at the European Swimming Championships in Glasgow last year, and he continued to show good form as he claimed the British 50m and 100m breaststroke titles in Glasgow last week.
But while those performances give him confidence, Peaty admitted he still faces a battle against the grind of the sport.
"In the winter, I almost had that time off mentally," said Peaty, speaking at a Science in Sport PROTEIN20 launch.
"The longevity of my sport, you know, when you're following a lap line, for 12,000 meters a day, 10,000 meters a day, it does get very tedious and you've got to stay motivated. So, for me, there's a lot of push and pulls."
The next target for Peaty is the world championships in Gwangju, South Korea, in July where he has his sights set on breaking his own new world record in the 50m breaststroke.
Peaty set the current mark of 25.95 at the 2017 worlds in Budapest, and could not match it in Glasgow last year with a 26.09.
"The 50m is one of those things... the harder you try, the slower you go," he said. "Obviously I tried a little bit too hard in Glasgow.
"It's still one of the fastest times ever, but for me that isn't enough, I think I want to get down a new world record every single time.
"I know that's not possible because world records are world records for a reason, everything has to be almost perfect but yeah I mean, come Guangzhou in the summer in three months' time I'm pretty sure I'll be at the right composition, right place in terms of that.
"And the right place mentally, because everyone thinks about, what you physically look like, what you physically do but if you're not there mentally then it's all for nothing."
:: Science in Sport ambassador Adam Peaty is supporting the launch of Science in Sport PROTEIN20. A low sugar, high protein bar. Available at www.scienceinsport.com