Caeleb Dressel swims during a training session at the OCBC Aquatic Centre this month in Singapore. (Yong Teck Lim/Getty Images)

Last summer, the best swimmers in the world gathered in Tokyo for the year’s biggest competition, and when the Pan Pacific championships wrapped, here’s what Australia’s Cate Campbell had to say about the always dominant American team:

“They came into this with their chests all puffed out, and we have kind of taken a little wind out of their sails, which has been really nice,” said Campbell, who won five gold medals at the event.

Never mind that the United States still easily topped the medal table; much of the buzz around the pool deck centered on whether the Americans had underperformed. “I would say we have definitely put them on notice,” Campbell said.

The U.S. team took note, but mostly of its own insufficient preparation. After a disappointing Pan Pacs, the American squad returned home and regrouped. With its swimmers both frustrated and vocal, USA Swimming switched gears and added an extended overseas training camp before this year’s world championships, where the swimming competition begins Sunday in Gwangju, South Korea. The team hopes the new plan not only pays dividends at this year’s most anticipated event but also provides a blueprint for next summer’s Tokyo Olympics.

“I think USA Swimming realized they misstepped last summer,” said Greg Meehan, who in May was named head coach for the U.S. women’s team in Gwangju. “They got to work right away to make sure this summer would be different.”

International events always pose huge challenges for Olympic officials, who spend months sorting through logistics to come up with a plan that allows athletes to maximize performance. Last year’s national championships ended July 29, and the team reported immediately to Dana Point, Calif., for a mandatory five-day training camp. Temperatures were hot, and the athletes were tired. After an 11-hour flight, the team arrived in Tokyo on the afternoon of Aug. 5 for a competition that began Aug. 9. They all faced a 16-hour time difference from their training camp, and many had only four days to adjust and train before Pan Pacs began.

“To try to acclimate to Asia in four days was just unrealistic,” said Meehan, who wasn’t with the squad last summer but will coach the women’s team through next year’s Tokyo Olympics.

The team got off to a slow start, winning 11 medals in the first three days of the four-day competition. Katie Ledecky swam a grueling double on the first day and settled for bronze for the first time in a major international competition: She finished third in the 200-meter freestyle, an event she won at the 2016 Rio Olympics.

“I wasn’t too disappointed with my swims at Pan Pacs,” Ledecky said in a recent interview, “but I knew that I was capable of a lot more. I didn’t swim my fastest times of the season at Pan Pacs, and I always like to have my big meet be my best meet of the year.”

The Americans were finding the podium but not always posting their best times. Caeleb Dressel had won five individual gold medals at the 2017 world championships but only one gold and two silvers a year later at Pan Pacs. Nathan Adrian, the second-place finisher in the 100 free at worlds, failed to make the Pan Pacs final in the event. Bethany Galat took silver in the 200 breaststroke at worlds and a year later also missed out on the final at Pan Pacs.

“Look at the results for Team USA,” said Meehan, who coaches Ledecky as well as the Stanford women’s team. “It wasn’t pretty across the board. Very few athletes went out there and were able to have their best competition.”

By the fourth and final day, the American swimmers appeared to be more comfortable in the water and won seven events. The final tally in the pool — 18 golds, 43 total medals — was on par with 2014 Pan Pacs haul but short of what the team did in 2010, when the Americans won 23 golds and 47 total.

Even before they left Tokyo, swimmers and coaches had begun assessing every aspect of the meet. “We totally reevaluated everything,” said Lindsay Mintenko, USA Swimming’s national team managing director.

The veteran swimmers kept questioning the stateside training camp and the quick turnaround in Tokyo. With both this year’s world championships and next summer’s Tokyo Olympics slated for Asia, USA Swimming knew that it needed a new game plan.

In recent years, before international meets, the team has almost always staged its camp closer to the competition site. For example, before the 2017 world championships in ­Budapest, the Americans went to Croatia. Before the 2016 Olympics, they assembled in Atlanta, which isn’t geographically close to Rio de Janeiro but is still just a one-hour time difference. But with so little time last summer between nationals and Pan Pacs, USA Swimming felt locked into a domestic training camp.

“Some things we can control and some we can’t,” Mintenko said. “One of those we can control moving forward was arriving in Asia earlier.”

Holding an international camp is no small undertaking. Around 80 people need to be transported, hotel rooms need to be booked, and pools need to be identified. But the feedback from athletes was steady, clear and overwhelming, and officials realized they need to hold training camp in Asia this year, allowing the athletes time to adjust and acclimate.

“I think the biggest thing was vocalizing some of those frustrations along with my teammates to the right people and making sure that we have a solid plan in place for this year,” Ledecky said.

It’s a big financial commitment — USA Swimming would not reveal actual numbers — but was deemed essential. Team officials explored their options but were quick to target Singapore. That’s where the U.S. team went before the 2008 Beijing Games, where American swimmers won 12 golds — twice as many as any other country and eight courtesy of Michael Phelps — and 31 medals overall.

USA Swimming staged a trial run of sorts in Singapore before December’s short course world championships, which were in Hangzhou, China. The change wasn’t solely geared toward worlds. USA Swimming has major international meets scheduled in Asia through the 2021 world championships in Fukuoka, Japan. If Singapore works out, the Americans probably will return for training camps the next two summers.

On July 8, the 45 U.S. swimmers who will be competing in Gwangju arrived in Singapore for a week-long camp. They trained every day at the OCBC Aquatic Centre, slowly adjusting to the time change. Then on Tuesday they left for South Korea — just a one-hour time difference — with the first races set for Sunday.

While USA Swimming is hoping for a big week one year ahead of the Tokyo Games, Mintenko said holding a long training camp overseas isn’t always a no-brainer, and swimmers still face some challenges.

“When you’re in a place for a long period of time before any competition, there can be some kind of fatigue,” said Mintenko, who won gold on the U.S. relay teams at the 2000 and 2004 Olympics swimming with her maiden name, Lindsay Benko. “Obviously, getting on the time zone will have a positive effect, but I also think there can be some negatives. Making sure the athletes don’t get stale, making sure they’re in an environment where they feel comfortable. That’s sometimes a hard thing to do. … It’s a very fine balance of too long to just right. It’s never perfect.”

Read more on the Olympics:

She’s 10 years old and loves to skateboard. She could be an Olympian next year.

U.S. Olympic Committee changes name to recognize Paralympians

Larry Nassar is in jail, but only one USOC official was fired? Yes, we need reform.

Congresswoman says USOC ‘has failed,’ proposes bill that could initiate an overhaul