For some athletes, today was the last chance to take part in the Tokyo Olympics.
They are too old, too exhausted or too financially stretched to wait for another year, after the pandemic forced its postponement.
One of them is 35-year-old Tetsuya Sotomura. When I met him on a sweltering afternoon earlier this week he was still hard at it in a converted factory building in a north Tokyo suburb, flying high into the air, spinning and tumbling on a massive trampoline.
Back in 2008 Tetsuya placed 4th at the Beijing Olympics, just missing a bronze medal. Since then he's fought injury that put him out of London in 2012 and Rio in 2016. Tokyo was to be his last hurrah, a hometown Olympics to end his trampolining career on a high. But another year is just too much.
"Back in 2008, if the Beijing Games had been postponed by a year I would have thought ok, it's another year to train, another year to grow," he tells me. "But now I am 35. A year feels like a very long time. So, I have decided retirement is the only option."
But there is another reason Tetsuya is getting off the trampoline. He thinks Tokyo 2021 may never happen.
"It's so uncertain. No-one knows the probability. If what awaits us next year is cancellation, I would have lost another year for nothing. So that is another reason to go now."
Enthusiasm for the Games has plummeted in Japan since Covid-19 arrived here in January. The Japanese government has closed Japan's borders to most foreigners to protect the country from imported cases, and many Japanese people are in no hurry to see them re-open for athletes or spectators.
TV reporters have been visiting the towns due to host various foreign teams and asking locals how they feel. The residents of a town north of Tokyo due to host the Brazilian team were clearly struggling to maintain any semblance of enthusiasm. An opinion poll by the Kyodo news agency found just 23% of people in Japan now support holding the games if Covid-19 infections are still widespread next year.
The latest figures from the World Health Organization (WHO) do not make for happy viewing. More than 15 million infections worldwide, and that number is growing by about a million every four to five days.
From the US to Brazil, from India to South Africa, suppression efforts are failing and infections are surging. Of course, a year feels like a long time, but many health experts say it is now very unlikely the pandemic will be contained by next summer.
At Kobe University Hospital in western Japan, Prof Kentaro Iwata says the only hope for the Olympics is a vaccine.
"If a vaccine is available it could be a game changer," he says. "Phase 1 and 2 trials have some promising results. I have not lost hope.
"But generally speaking vaccines don't eradicate a virus, they lower the incidence by about half. So, I don't think Covid-19 can be eradicated. Instead [even with a vaccine] it will continue into 2021."
Prof Iwata is particularly concerned looking at what is going on in the US, the country that more than any other pays for the Olympics.
"The US will suffer from Covid for many months to come," he says. "Can athletes come from the US come here? Can we have the Olympics without Americans? Most likely not. The priority must be the safety of the athletes and of Japanese people.
"The US TV companies may not like that, but is the Olympics a sports competition or a TV show?"
There is one seemingly simple solution: push the Tokyo Games back another year to 2022. It is far more likely the pandemic will have run its course by then. But that has been ruled out by the Japanese government. From his home in Montreal the longest-serving member of the International Olympic Committee, Dick Pound, told me it is now 2021 or bust.
"What we do know is 2021 is our last chance," he says.
"It's not something we can put off until 2022 or 2023. I don't think it's fair to expect Japan to keep the balls in the air any longer. To the extent that it's safe for the athletes to come, every effort will be made for the Games to go forward.
"That said, if public health authorities in Japan and around the world conclude that it's not safe enough, there is probably no alternative but to say, 'oh well, the pandemic is the new war'."
The only occasions the Olympic Games have been cancelled was during the two World Wars, and one of those was - you guessed it - Tokyo, in 1940.
So how about one final idea: a much-simplified Games, with foreign athletes going through quarantine before arrival but foreign spectators kept away?
According to Dick Pound, this is a non-starter.
"In the North American phrase - you either have the fish or cut bait," he says. "Japan would have to decide, do they want the Games to go ahead or are the risks too much? In which case Japan would probably propose, and the IOC would accept, cancellation."
On Thursday night inside the Olympic stadium they held a ceremony to reset the clock, one year until the opening ceremony. Japanese Prime Minister Shinzo Abe insists the Games must go on but Covid-19 is almost certainly not listening.