Army triathlete Captain Kat Matthews says she expects this weekend's Ironman event in Tulsa, USA, to be "tough".
Capt Matthews, who has already qualified for October's World Championships, has had to battle the British weather and the coronavirus pandemic during her training.
Her last race in America saw her win in Florida but she says she expects this race to be a more difficult challenge.
She said: "It's the first full-distance long, Ironman distance, this year.
"My last one was in December in Florida which I took the win at. This one's a little bit more steep in competition."
That performance came despite a setback in training over the winter months because of the COVID-19 pandemic.
"For everybody, the last few months have been even harder than it was last year in a way because we've had the British weather to contend with," said Capt Matthews.
"A big part of it was [that] pools had shut again so I was without the opportunity to swim in the lake because it was too cold to be conducive to training."
However, Capt Matthews was lucky enough to get away to an intensive training camp in Lanzarote with some team members and a new coach.
"I made the most of the pool time I had there and came back deliberately when the pools opened in England," she said.
For this weekend's event, Capt Matthews said she's "really hoping I can be in contention for that top three".
She said: "It's not a very flat course. On the two previous Ironmans I've done, it was two very flat courses.
"The bike course is much hillier to start with and it has a lot more technical aspects to it.
"For me, it's much more entertaining than just a straightforward flat out and back.
"I've had a little look at the route and I really invest some time in looking at the elevation gain, where the hills are, where I might be able to put a bit more power down on the bike."