TOKYO — Other than backstrokers, Olympic swimmers aren’t supposed to go in reverse. But through the first three days of the Tokyo 2020 meet, the overarching themes have been the plethora of slower-than-usual times and the lack of new standards being set. In many events, when compared to the 2016 Rio de Janeiro Games, the best swimmers in the world are going backward — which, given the strange set of circumstances, is hardly a surprise.

Through 12 finals across three mornings at Tokyo Aquatics Centre, eight of the gold medal-winning times were slower than the corresponding times in the same events in Rio. By contrast, in Rio, those same 12 events saw eight time-drops from the 2012 London Games. In Rio, the first three nights of finals saw five world records broken. In Tokyo, where finals are being held in the morning, there has been just one so far, by the Australian women’s 4x100 freestyle relay.

Why might that be? Pick your reason: A global pandemic that effectively shut down the sport for more than a year and had swimmers scrambling to find pools in which to train. The lack of fans in the stands in Tokyo, due to efforts to stop the spread of covid-19. And an upended competition format, implemented so that NBC can air finals live during prime time in the United States, in which finals are held in the mornings, Tokyo time, and preliminary heats the night before.

The trend began in the first medal event of the Olympic meet, the men’s 400-meter individual medley, which American Chase Kalisz won with a time of 4 minutes 9.42 seconds — nearly three seconds slower than the 4:06.75 that he swam in Rio, which was good enough only for silver. In fact, Kalisz’s time was the slowest for a gold medalist in an Olympics or world championship in that event since 2005 Worlds.

But at least Kalisz dropped a tiny bit of time from his prelim swim the night before (4:09.65) — all seven of his fellow competitors in the final went the other way.

“You look at my time, it’s pretty terrible,” Kalisz said. He pointed to the flip-flopped schedule as a likely cause for the higher times lack of drops in gold medal times. “This is not something we’re used to. I’ve done it one [other] time in my life … and it didn’t necessarily go well.”

Russell Mark, USA Swimming’s national team high performance manager and top numbers-cruncher, noted times haven’t been down across the board, only at the top. In the men’s 400 IM, for example, while Kalisz’s winning time was down and other swimmers added time in the final, the preliminary heats were blazing, with the time required to make the eight-man final (4:10.20) more than three seconds faster than it was in 2016 (4:13.55).

In nine of the 10 individual finals so far, it required a faster time to get into the eight-swimmer field than it did five years ago in Rio, the only exception being the women’s 400 IM. In other words, prelims during these Olympics have been almost uniformly faster than in Rio, not slower.

“The finals are more about the race than the time, obviously,” Mark said. “If anything is affecting [the winning times], I’d say it might be the morning dynamic.”

Where performances are going backwards is in some of the finals themselves. In five of the 10 individual finals so far, at least half the field added time from the previous round, whether prelims or semifinals.

On Tuesday, that included the women’s 100 breast, in which American teenager Lydia Jacoby was the upset winner in 1:04.95, while four of the next six finishers, including silver medalist Tatjana Schoenmaker of South Africa and bronze winner Lilly King of the United States, added time from the semis.

When FINA (swimming’s international governing body) and the IOC unveiled the Tokyo swimming schedule in 2018, featuring evening prelims and morning finals, the Japanese Swimming Federation lodged its displeasure, saying in a statement it was “highly regrettable that the Tokyo 2020 swimming finals [will be] held in the morning.”

The schedule has become a flash point especially for non-Americans at the Tokyo meet, some of whom have expressed resentment that the traditional format was upended to satisfy NBC and its U.S. viewership.

“Unfortunately, in our world, money decides everything, and they don’t pay attention to the needs of the athletes,” Russian breaststroke star Yulia Efimova said, according to Russian media reports. “We would have seen better results if we had finals in the evening. World records would be broken.”

USA Swimming officials did their best to prepare the Olympic team for the flip-flopped schedule, using the evening prelims/morning finals format for one of its pro meets in May in Mission Viejo, Calif. But when it came to the Olympic trials last month in Omaha, they returned to the standard morning prelims/evening finals, which is what NBC preferred.

In a roundabout way, this year’s struggles in the pool have served to make Michael Phelps’s historic showing in Beijing in 2008 — the last major international competition to use the flip-flopped schedule — look even more impressive. Phelps won a record eight gold medals at that Olympics, all of them at morning finals sessions, and lowered a world record a total of seven times — including a 4:03.84 in the 400 IM that still stands.

“Absolutely incredible,” Kalisz said of Phelps’s showing in Beijing. “It’s a very tough challenge to do a [prelims] at night and wake up and do in the morning, especially a 400 IM.”

With five days left in the meet, and with some of the most dominant swimmers in the world yet to be unleashed, there is still plenty of time for world records to fall. The women’s 200 back (Australia’s Kaylee McKeown), the women’s 200 free (Australia’s Ariarne Titmus) and the men’s 100 free and 100 fly (both Team USA’s Caeleb Dressel) appear particularly vulnerable this week.

The world of swimming is overdue for some monumental record-smashing. Since the end of 2019, just two Olympic events have seen a world record lowered, both by Australians: McKeown set a new mark in the 100 back during that country’s Olympic trials last month, and the Aussie women’s 4x100 freestyle squad set a new world record in winning gold here Sunday.

That would suggest the world of elite swimming, understandably, has been slow to return to its historical, pre-covid levels of progress.

“We’ve been through a tough time. The world has been through a tough time,” said British star Adam Peaty, who has dominated the men’s 100 breast since 2015, winning gold here Monday. “It’s been a different journey. We’ve had no training camps, no racing abroad.”

Peaty also pointed to the lack of fans in the stands as a deflating dynamic, saying, “It’s been hard to find that emotion, to find that kind of performance when there is no crowd.”

In Rio in 2016, Peaty had his sights trained on lowering his own world record, which he did with a 57.14 in the final. Five years later, he came to Tokyo just aiming to win gold — and he did that as well, albeit with a time, 57.37, that was more than a half-second off his current world record, a 56.88 he dropped at the 2019 world championships.

“This Olympics was very different,” Peaty said. “This past year, it felt almost like we were under siege.”