The decades-long quest for the first Olympic gold medal for the U.S. women's volleyball team ended Sunday when the Americans finally broke through with a 25-21, 25-20, 25-14 victory over Brazil.

The United States, which had won three silver medals and two bronze since first getting on the medal stand in 1984, got to the top step by beating the team that denied it a chance at gold in the final match of the 2008 and 2012 Olympics.

Captain Jordan Larson, who was part of that silver-winning team in 2012 and the bronze medal team five years ago, paved the way with her leadership on the court and her strong play on the attack and on defense.

Larson and middle blocker Foluke Akinradewo Gunderson, who both came back for a third Olympics after falling short in Rio de Janeiro, now have a complete medal collection following the final Olympic match of their careers.

The victory also allowed U.S. coach Karch Kiraly to join Lang Ping of China as the second person to win gold as a volleyball player and then lead a country to gold as coach. Kiraly won gold indoor as a player in 1984 and 1988. He also won gold in beach volleyball in 1996.

The U.S. got off to a fast start by scoring the first four points behind strong attacking by Michelle Bartsch-Hackley. It never trailed in the opening, winning it 25-21 on a soft shot by Bartsch-Hackley that gave her eight points in the set.

The Americans played from ahead for most of the second set as well, and Larson's well-placed soft shot at the net put them up 22-17. They closed out the set when Carol Silva's serve went long.

That pattern continued in the third set, and the match ended in fitting style with a kill by Larson, completing a sweep by the Americans of all nine sets in the knockout stage. The U.S. players all gathered on the floor in a tearful hug.

Brazil had won gold in either men's or women's indoor volleyball in four straight Olympics, with the men claiming the title in 2004 and 2016 and the women in 2008 and 2012.

But it will leave only with a silver this year, after the women lost for the first time in Tokyo following seven straight wins. The men lost a semifinal match to the Russians and then the bronze medal game against Argentina.

Brazil played the match short-handed after outside hitter Tandara Caixeta was sent home before the semifinals following her suspension for a potential violation of anti-doping rules. Tandara's lawyer said a banned substance found in a July test was introduced accidentally into her system.

The U.S. also dealt with absences. Opposite Jordan Thompson, who led the Americans in scoring in the first three matches, didn't play again after rolling her right ankle in the fourth pool play match against the Russians.

But the depth that has made the U.S. one of the top teams the past two decades despite no gold medal overcame that and an injury that sidelined setter Jordyn Poulter for the quarterfinal. Annie Drews stepped up in Thompson's place and the U.S. didn't miss a beat.

The journey to this stage has been a long one for a U.S. women's team that started more than 40 years ago when the 1980 Olympic squad made the decision to begin year-round training, only to get denied the opportunity to compete because of a U.S.-led boycott of the Games in Moscow.

But the foundation had been put in place, and the Americans have won six medals in the past 10 Olympics and now finally have their gold.

In the bronze medal game, Serbia beat South Korea 25-18, 25-15, 25-15 to go home with a women's volleyball medal for the second straight Olympics. The Serbians won silver in 2016 for their first medal in the sport.

TOKYO, Tokyo —

Sue Bird capped off her unblemished 17-year Olympics run with a record fifth gold medal.

All she and longtime U.S. teammate Diana Taurasi have done on the international stage is win and now stand alone with five gold medals — the first basketball players ever to accomplish that feat — after a 90-75 win over Japan Sunday at the Tokyo Games.

The U.S. has now won the last seven Olympic gold medals matching the country’s men’s program for the most ever in a row. The men did it from 1936-68.

With Bird orchestrating the flow of games and Taurasi’s scoring, they have been a constant force for the U.S., providing stability for the women’s program since the 2004 Athens Games. They have won all 38 of the games at the Olympics they’ve competed in.

They walked off the court Sunday arm-in-arm, knowing their work was done.

The names have changed around the pair, including greats Lisa Leslie, Sheryl Swoopes, Tina Thompson, Tamika Catchings and Sylvia Fowles, but the results haven’t.

The Americans are on a 55-game Olympic winning streak dating back to the bronze medal game of the 1992 Barcelona Games.

The U.S. let Japan know that wasn’t going to change on Sunday.

The Americans jumped out to an 18-5 lead behind a dominant first quarter by Brittney Griner. The team led 23-14 after one as Griner had 10 points, taking advantage of the undersized Japanese team. Japan was able to get within six in the second quarter before the Americans went up 11 at the half and never looked back.

As the final buzzer sounded, Bird and Taurasi embraced and then proceeded to hug all of their teammates and the coaching staff.

Griner finished with 30 points, making 14 of her 18 shots.

While Bird has said she is moving on and Taurasi has been noncommittal about her plans, the future is bright for the U.S. behind Griner, Breanna Stewart and the six newcomers on this year’s team. That included A’ja Wilson, who will be counted on to keep the streak going three years from now at the 2024 Paris Games. Wilson, who celebrated her 25th birthday on Sunday, made her presence felt in her Olympic debut, scoring 19 points in the gold medal game.

But there were other milestones of note besides Bird’s farewell.

The victory also made Dawn Staley, the first Black women's basketball coach for the U.S., the second woman to win a gold medal as a player, assistant and head coach joining Anne Donovan.

The game also marked the end of Carol Callan's run as the national team director. She started right before the Americans won the first gold of this streak in 1996 and has been the architect for this unprecedented run.

Japan, which was the only one of the 11 other teams to ever have beaten the U.S. in an Olympics, won a medal for the first time in the country's history. The team's best finish before Sunday was fifth.

The host nation has been on the rise since it hired coach Tom Hovasse. He said when he got the job 4 1/2 years ago that his team would be playing against the U.S. for the gold at the Tokyo Games — and would beat them.

He was half right.

The two teams met in preliminary pool play and the U.S. won by 17 points after trailing by two after the first quarter. Just like that game, the Americans used their dominant post advantage to control the title game. Japan's biggest player was 6-foot-1 — no match for the imposing front line led by Griner, who is 6-9.

While the general public and family members couldn't attend the games because of the coronavirus pandemic, Bird did have fiancee Megan Rapinoe in the stands cheering her on. Rapinoe helped the U.S. women's soccer team win a bronze medal earlier this week, scoring two goals in that game.

A large contingent of Japanese volunteers, who had been in the Saitama Super Arena for the entire tournament sat and applauded their team. No actual cheering was allowed because of the coronavirus pandemic.

TOKYO —

Related video above: Tokyo 2020: Anti-Olympic protesters rally to demand cancellation

Was it the strangest Olympics ever, staged during a deadly global pandemic, with no fans? How about the angriest, awash in protests and fierce opposition from large swaths of the host nation?

The scariest, with fears of new coronavirus variants and surging cases plaguing Japan— though mostly dodging those in the Olympic "bubble" — throughout the two weeks of sports? Or maybe, as athletes banded together under moments of intense stress, the kindest?

As tens of thousands of athletes, journalists and officials get ready to pack up and leave Monday, Japan will be left to pick over the answers to these questions, maybe for years. Amid the lingering glow from the televised pomp and the indisputable athletic drama, whatever you call these Olympics, it's worth stopping to consider how Japan sees them.

They were sold, well before the pandemic, as the symbol of Japan's recovery from the destruction of the 2011 tsunami and nuclear meltdown. The rhetoric now tends to focus on their link to the world overcoming coronavirus.

But does that really work in a country where thousands are still getting sick each day, let alone in other, even worse-hit nations that have sent athletes to Tokyo? Many here, while proud that Japan is on the verge of pulling off what many thought impossible or, in some corners, highly inadvisable, still believe these Games were forced on the country and that their real cost, possibly in lives lost, is yet to be paid.

Others are simply relieved they are over. And a large number maybe even enjoyed the ride, reveling in the sports themselves, Japan's surprisingly strong medal haul and the generally hospitable way the world was welcomed during a period of illness, fear and uncertainty.

Using some of the dozens of interviews conducted during and before these delayed and disputed Pandemic Games, The Associated Press takes a look at what some Japanese think they mean.

Is it representative of a nation of 126 million? Of course not. But the glimpses into the views of some of the people who lived through this Olympics offer a chance to cut through, in sometimes surprising ways, the government and IOC rhetoric that emphasized harmony and revitalization, and get a bit closer to the heart of the nation's sentiment.

THE BEGINNING

It started with a muted opening ceremony and an empty stadium, with moments so quiet that the shouts of protesters could be heard from the streets outside. Many residents watched with mixed feelings, to say the least, isolated from the Games by organizers trying to keep the Olympic visitors from mingling with the public, forced to modify their lives during a record wave of virus cases and yet another state of emergency.

Many were opposed, and that feeling persisted. But there was nuance, too — a desire to put the country's best face forward, now that the inevitable was happening, and a notion that this spectacle could act as a salve.

"I am very emotional and teary-eyed while watching the TV because even during the pandemic, the Olympics will still go on," Riza Nagumo, 53, a housewife, said. "I was praying so much to have this Olympics be a very successful event, to heal the world."

At a normally bustling intersection in Tokyo's Shibuya neighborhood, large screens that usually blast advertisements and show television were switched off. Many bars and restaurants were closed, and public viewing locations across Japan were shut down amid rising infections.

"Everyone is just enduring this," said Harumi Wada, a Tokyo resident. "But to hold the Olympics, despite everything, I feel there's a dissonance, and I think that distrust toward the government is getting stronger."

THE FAMILY

Despite the disruption, delays and disputes of these Games, the ban on spectators and big gatherings proved a surprising boon for some families.

While it's true that some bars and restaurants continued to see drinkers flouting pandemic restriction rules, even as late as Friday night, many Japanese stayed home with their relatives — and were delighted with the excuse to do so.

"We are often too busy in our daily life to have this kind of quality family time," said Ikuko Tozuka, 53, who gathered with her husband and two adult daughters in front of their TV screen in Oiso, west of Tokyo, to watch the Games. "So I am very happy that this Olympics has given us an opportunity to be together."

Hiroshi, the father, 58, even bought a new TV set to watch the Games with his family.

"It was actually good that this COVID-19 pandemic compelled us as a family to come together and watch the Games in this way," said Yu, his 26-year-old daughter.

THE PROTESTERS

Throughout the Games, small knots of protesters gathered to provide voice to what a much larger, mostly silent chunk of Japan was thinking. They chanted, "Cancel the Olympics." They carried banners reading, "No Olympics 2020 — Use that money for COVID-19" and "Is it more important than human life?"

Were these very public demonstrations representative of the whole country? It's complicated. Many said in polls they strongly opposed the Games; an unknown number may have been silently taking a wait-and-see attitude, hoping for the best.

In AP interviews conducted over the months between the postponement and the start of the Games, there could be found a feeling of resentment that the government had pushed ahead partly because of pressure from the IOC, which would have faced billions in lost television rights income without the Games. There was also fear over the Olympics spreading new strains of the coronavirus. The government's main medical adviser said it was "abnormal" to hold the Olympics during a pandemic.

"It's unethical to proceed with such a big event, with more than 10,000 athletes coming to Tokyo, all situated in one area," said Masa Yamagata, a Tokyo resident. "We can't enjoy it anyway. We can't celebrate it."

PAST AS PRESENT

Along with the anger and fear, these Games had a nostalgic element for some older Japanese who remembered the Summer Games of 1964, when Japan celebrated its rebuilding from the war and the turbulent years that followed.

Some felt remorse — a sense of what might have been — because these Games would be so much more circumscribed than the last time they were in Tokyo.

There was also gratitude. Thanks to these Games, Seiichi Kuroki, 55, saw his relationship with his 85-year-old father, Masatoshi Kuroki, deepen as they talked about Masatoshi's role as a marshal at the opening ceremony of the 1964 Olympics.

"I am very grateful for that," Kuroki said. "He looks happy when I ask him questions such as, 'What were you doing then at the Games?' Because that is his legacy. "

There was a tinge of sorrow, however, for Takemasa Taguchi, as the 83-year-old remembered Tokyo's celebratory mood in 1964.

"I am so sad about this situation," Taguchi said. "I was hoping that we could have celebrated and danced together with people from all over the world."

SOCIAL CHANGE

Some hoped the Games would bring change to Japanese society, where minorities still suffer from discrimination and prejudice. Few felt that the Games would solve all of Japan's social issues: Can an Olympics event ever live up to the expectations that are heaped on it? But with the world's attention focused on Japan, some saw movement forward on the issues they cared about.

Ahead of the Games, Makoto Kikuchi, a 34-year-old professional boxer, decided to come out as a lesbian.

"By speaking openly and becoming one of the out athletes, I hoped to be as helpful as possible for those who feel lonely," Kikuchi said.

The Tokyo Games included 179 openly gay, lesbian, bisexual, transgender, queer and nonbinary athletes, according to Outsport.com. That's more than three times the number from the 2016 Games in Rio.

While same-sex marriages are not legally recognized here, Fumino Sugiyama, a transgender activist and former fencer on Japan's women's national team, said support of sexual diversity has slowly grown.

"It is truly great that a path has finally been created for athletes to be able to compete while being their authentic selves in sports," said the 39-year-old, who was nominated to the Japanese Olympic Committee's board of directors before the Games.

April Ross now has the complete set of Olympic beach volleyball medals: silver in London, bronze in Rio de Janeiro and a gold she won with Alix Klineman at the Tokyo Games on Friday with a victory over Australia.

The Americans beat Mariafe Artacho del Solar and Taliqua Clancy of Australia 21-15, 21-16 under a blazing sun in a match that was mercifully quick for the biggest crowd yet at Shiokaze Park — about 60 people in the temporary stadium that seats 9,600.

Playing in 92-degree Fahrenheit (33 Celsius) temperatures under the hot Tokyo sun, the Americans finished off the Aussies in 43 minutes. In the bronze medal match earlier Friday, Joana Heidrich and Anouk Verge-Depre of Switzerland cruised to a straight-set victory over Latvia.

The silver for Australia was its first beach volleyball medal since Natalie Cook and Kerri Pottharst took gold on Bondi Beach in 2000. But they were never really close against the Americans, who tied for the top spot in the Olympic qualification points race and lost just one set in seven matches in Tokyo.

With side changes every seven points and technical timeouts every 14, the players retreated to benches, where an awning was rolled up over their heads for shade. A towel covered the seat so they wouldn't stick to the hot cushion; support staff put icepacks on their heads, or wrapped them in wet towels.

And then there was hydration. So much hydration.

Klineman, a first-time Olympian, and Ross, who has three medals in as many trips to the Summer Games, needed just 20 minutes to claim the first set. They fell behind 2-0 in the second before scoring 10 straight points to pull away.

That silenced the chants of "Aussie! Aussie! Aussie! Oi! Oi! Oi!" from the Australians in their bright yellow shirts and brought out the cheers of "U-S-A!" from those in the red, white and blue. Australia survived three championship points before Artacho del Solar served into the net to seal the U.S. victory.

After a long hug, Klineman went to the bench to douse herself in water, then the pair went over to the stands and posed with an American flag.

The Swiss cruised to a straight-set victory over Latvia to claim the first Olympic medal ever for their country's women on the beach. They edged Tina Graudina and Anastasija Kravcenoka 21-19 in the first set before opening a 5-1 lead in the second and pulling away to win 21-15.

Graudina was the first person to make the Olympics after coming up through an NCAA beach volleyball program that started in 2012. She played at Southern California, where she was the 2019 national player of the year and led the Trojans to the 2021 national championship.

TOKYO —

Set the alarm for Day 14 of the Tokyo Games and watch Allyson Felix attempt to win a 10th track and field Olympic medal over breakfast. Then stay up late to catch the U.S. men's basketball team play for the gold.

Most of Friday's high-profile events are early, including the jumping team event at Tokyo's Equestrian Park. Jessica Springsteen, daughter of Rock and Roll Hall of Famer Bruce Springsteen and his E Street Band wife, Patti Scialfa, will attempt to win her first Olympic medal.

Medals will be awarded in the women's marathon, women's high jump, women's 10,000-meters, men's javelin, men's 1,500-meters and both 4x400 meter relays.

Women's Volleyball

April Ross now has the complete set of Olympic beach volleyball medals: silver in London, bronze in Rio de Janeiro and a gold she won with Alix Klineman at the Tokyo Games on Friday with a victory over Australia.

The Americans beat Mariafe Artacho del Solar and Taliqua Clancy of Australia 21-15, 21-16 under a blazing sun in a match that was mercifully quick for the biggest crowd yet at Shiokaze Park — about 60 people in the temporary stadium that seats 9,600.

Playing in 92-degree Fahrenheit (33 Celsius) temperatures under the hot Tokyo sun, the Americans finished off the Aussies in 43 minutes. In the bronze medal match earlier Friday, Joana Heidrich and Anouk Verge-Depre of Switzerland cruised to a straight-set victory over Latvia.

The silver for Australia was its first beach volleyball medal since Natalie Cook and Kerri Pottharst took gold on Bondi Beach in 2000. But they were never really close against the Americans, who tied for the top spot in the Olympic qualification points race and lost just one set in seven matches in Tokyo.

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Here are some things to watch (all times Eastern):

Track & Field

Allyson Felix came to the Tokyo Games chasing history. The track star has nine medals across four Olympics, most of any woman in U.S. track and field history.

One more medal would give her 10 — enough to tie Carl Lewis' overall Olympic record and pass Merlene Ottey of Jamaica for most in women's track and field. Felix will run in the finals of the 400-meters, but at 35 years old, she knows the task will be difficult.

"You get older," said Felix, "and it seems like it’s harder."

Men's Basketball

France made sure the U.S. wouldn't win a medal at the 2019 Basketball World Cup, then beat the Americans again to open the Tokyo Games.

If France beats the U.S. for a third consecutive time, the country will take over as Olympic champions.

The rematch is set: France and the U.S. play for gold, and France has made it this far in the Olympics only twice before, falling to the U.S. in the gold-medal games at Sydney in 2000 and at London in 1948.

The Americans are bidding for a fourth consecutive gold medal, and Kevin Durant can join Carmelo Anthony as the only U.S. men with three basketball golds.

No nation has ever defeated the U.S. men twice in the same Olympics.

Equestrian

Jessica Springsteen failed to qualify for the individual jumping finals at Tokyo’s Equestrian Park in her first Olympic Games, but the daughter of Bruce Springsteen can still medal in the jumping team event.

The 29-year-old will be part of America’s four-rider entry.

The U.S. won the event at the FEI World Equestrian Games in 2018 and will be seeking a record fourth Olympic gold medal in the team jumping event. The Americans have won a record nine Olympic medals in the team jumping event, including silver at the Rio Games.

Water Polo

Greece plays Hungary and Serbia takes on Spain in the semifinals of the men’s water polo tournament.

Each game is a rematch from the first day of group play in Tokyo. Spain beat Serbia 13-12 in their first matchup, and Greece held off Hungary for a 10-9 win.

Greece is one win away from its first men’s water polo medal at the Olympics. Serbia is looking for its second straight title after it won in Rio de Janeiro in 2016.

Men's Baseball

South Korea plays Dominican Republic in the bronze medal baseball game. The U.S. beat South Korea to send the defending champions into the bronze medal game.

TOKYO —

The scoreboard at the Shiokaze Park beach volleyball venue said: “Challenge successful. Ball out.”

That didn’t make any sense.

And the Americans' survival was riding on it.

“The referee just said, ’Wait, wait, wait. We’re sorting it out,” Canada’s Heather Bansley said on Sunday after winning a twice-reversed challenge to oust Sarah Sponcil and Kelly Claes 22-24, 21-18, 15-13.

“I think they’re just sort of working out some kinks,” said Bansley, a two-time Olympian who is paired with Brandie Wilkerson in Tokyo. “We trust the technology they have. At least you know the correct answer, and you work from there.”

After losing the first set and falling behind 10-4 in the second, the Canadians rallied to force a tiebreaking third set, first to 15 (must win by two points). They led 12-11 when Sponcil’s serve went past them and bounced off the sand.

The linesman’s ruling was that the ball was out, but the Americans challenged the call, using a system that was used in the Olympics for the first time in Rio de Janeiro. The close-up, slow-motion replay on the stadium video board showed the ball had clearly missed the blue tape that signifies the court boundary.

It was out.

But somewhere in the process of getting that information to the court, there was a glitch: The video board said the ball was out and the challenge was successful, which isn’t possible. A member of the Canadian delegation sitting in the mostly empty arena shouted, “It was out!”

The players complained to the referee, and the stadium announcer explained that the challenge would be reviewed again. The call was corrected, and instead of a 12-12 tie it was 13-11, with Canada leading.

Claes said she's never seen that before. (A team cannot appeal the decision in a challenge, but in this case, the problem arose in communicating the decision to the players.)

“I thought it was in, and I mean, it sucks,” she said, noting that they blew a 10-4 lead in the second set. "It shouldn’t have even come down to that third set. We did such a good job in the second, and then just let them back in.”

Wilkerson, a first-time Olympian, knocked down a pass that got too close to the net for a triple set point, and they won it when she hit it over on the second shot to a wide-open part of the court.

That ended the stay of Claes, 25, and Sponcil, 24 — the youngest American team ever to qualify for the Olympic beach volleyball tournament. They are both two-time NCAA champions — at UCLA and Southern California, respectively — and the first Olympians to come up through a U.S. college beach volleyball program that started in 2012.

They entered the games as the No. 3 ranked team in the world and certainly the hottest, winning the last two events of the pandemic-extended qualifying period to grab the second U.S. spot in Tokyo. In the process, they knocked out five-time Olympian Kerri Walsh Jennings.

And they would still be younger for the 2024 Paris Games than any of the other American beach volleyball players in Tokyo are now.

“Huge learning moment for us," Claes said. "It sucks right now. It’s probably going to suck for a few weeks. But probably looking back I’ll for sure look at that and take that into account. But right now, like, it stinks."

On the men's side of action on Sunday, Americans Phil Dalhausser and Nick Lucena got knocked out of the Olympic beach volleyball tournament on Sunday by Cherif Samba and Ahmed Tijan of Qatar.

Related video above: U.S. Women’s Soccer Team trained for Tokyo heat

Restricting your blood flow sounds like a dangerous thing to do, but it's exactly what some Olympians, athletes and surgery and physical therapy patients have done to strengthen their muscles and speed up recovery.

The origins of this practice go back to 1966, when -- while sitting on his heels during a Japanese temple ceremony -- Yoshiaki Sato noticed his calves felt tingly and pumped up. Sato wondered if his limited blood flow was the key to experiencing that sensation, said Steven Munatones, the CEO of KAATSU, an eponymous blood flow restriction product and education company. Munatones cofounded KAATSU Global -- which translates to "additional pressure" in English -- with Sato in 2014 after being mentored by him about the Kaatsu technique for 13 years in Japan.

Seven years after that initial tingly feeling, Sato "experimented with different kinds of bands placed on different locations on his body -- from his head to his torso to his lower legs," Munatones said via email. "In 1973, he experienced a broken ankle and rehabilitated himself using KAATSU."

This was the first experimentation with KAATSU cycle mode, Munatones added, which is when bands with internal "air bladders" are inflated for 30 seconds as the bands compress around upper limbs, then deflate for five seconds before repeating the cycle. This rhythmic compression slows the blood flow back to the heart and therefore allows the veins and capillaries in the treated areas to engorge with blood -- visible as the skin gradually reddens -- while you're exercising, Munatones said.

This engorgement expedites several naturally occurring biochemical reactions, such as secreting nitric oxide, human growth hormone, insulin growth factor-1 and beta endorphins, all of which have differential roles in increasing blood supply, preventing tissue damage, regulating body composition and muscle growth, growing bone and tissue, and suppressing pain.

"Individuals exercise during the application of BFR to improve muscle mass, muscle strength, reduce pain, improve recovery, increase cardiovascular capacity and augment sports performance," said physical therapist Nicholas Rolnick via email.

Since Sato's discovery and subsequent studies on thousands of people, athletes, fitness enthusiasts and Olympians -- including long-distance runner Galen Rupp, diver Laura Wilkinson, swimmer Michael Andrew and alpine skier Mikaela Shiffrin -- have benefited from the technique. But you don't have to be an athlete to use Kaatsu or blood flow restriction training -- here's what experts say you should know before you try it.

How it works

When someone exercises while practicing Kaatsu or blood flow restriction, blood and metabolic byproducts are "stuck in the muscle, unable to leave," Rolnick said.

"The metabolites increase muscle fatigue, causing the muscle to work much harder than it normally would to produce a contraction at light loads," he added. "We have to work very hard to keep up with the exercise and that extra effort, paired with the fatigue produced through the BFR, accelerates muscle mass and strength gains."

Muscle fibers required to perform high-intensity actions -- such as jumping, throwing, lifting weights or kicking -- are recruited at lower intensities than usually required, said Stephen Patterson, a professor in applied exercise physiology and performance at St Mary's University, London, via email. That means someone could lift 20% to 30% of their maximum weight instead of the usual 70% or greater, and still experience a response like that of training with heavier loads, he added.

Need-to-knows before attempting BFR

People these experts have sold related products to, treated or studied include athletes of nearly all levels of ability, people who lead sedentary lifestyles, and those recovering from injuries, and range from 18 years old to 104.

The ability to use much lower loads when blood flow restriction training to build muscle and increase strength "is especially beneficial for those who are injured or have other conditions that do not allow them to either lift heavy or perform high-intensity aerobic exercise," Patterson said. This includes people who have recently had surgery or are paraplegic or quadriplegic.

"Major problems in the rehabilitation setting are the inability for patients to effectively strength train due to an injury or post-surgical precautions as well as pain," Rolnick said. "The growth of BFR training allows those individuals who would be unable to challenge their bodies under normal circumstances a chance to build more strength and muscle mass during times where it would be near impossible."

If you have just had surgery and have large incisions with stitches and you want to practice Kaatsu immediately, talk to your doctor first, Munatones said. "The reason why is because the incision will dramatically heal much, much faster than normal and their skin can grow very quickly over their stitches - which usually surprises orthopedic surgeons how quickly the body recovers using KAATSU."

Groups for whom blood flow restriction might not be appropriate include people with hypertension, uncontrolled diabetes, obesity, kidney disease, arterial calcification, a history of blood clots and medications or conditions causing higher risk of clotting, venous thromboembolism, vascular diseases, sickle cell anemia, cancer, poor circulatory systems or open fracture, these experts said.

Potential side effects have included lightheadedness, tiny red spots on arms, bruising near the equipment, feelings of pins and needles, and nerve damage, some of which can be avoided by properly practicing blood flow restriction.

Contact your doctor before trying this type of training, or if you experience these or other negative side effects.

How to practice the technique

Regarding equipment, Patterson recommended using medical grade-type products that will give you a reading to ensure the pressures advertised are true. "Exercise bands and other material etc. may be able to restrict blood flow but from a safety perspective there is no idea what level of restriction you are applying," he wrote via email. That could limit adaptations and responses or cause injury.

"There are many cuffs on the market but my line in the sand is a pneumatic cuff that can be inflated either automatically or manually (like a blood pressure cuff)," Rolnick said. "Each of these types of cuffs can carefully measure the amount of blood is restricted to increase safety profile. This is very important because as BFR continues to grow, more cuffs are going to enter the marketplace that may not be adequate or appropriate."

Rolnick and Patterson advised anyone starting out with blood flow restriction to work and train with trusted practitioners to determine what cuffs would be consistent with your goals -- and to understand how and when to use this type of training. Otherwise, Rolnick added, you could be at higher risk of experiencing a negative outcome -- especially since an ordinary exercise band can't measure how much pressure you're applying.

You can expect burning sensations or soreness during or after the first couple of sessions, but these generally subside by the third session, said Hunter Bennett, a lecturer in exercise science at the University of South Australia, via email.

Once you inflate the cuff, you could practice blood flow restriction by alternating repetitions and rest while training your preferred muscle group, Bennett said.

The consensus among these experts is that using blood flow restriction two to four times a week is required for results to occur.

TOKYO —

Usain Bolt might be long gone from the sprint scene. It doesn't mean Jamaica has slowed down one bit.

Nobody has, at least not on the women's side of the sport.

An opening day at the Olympics that's supposed to produce little more than a brisk jog for the world's best at 100 meters turned into something very different Friday.

Reigning world champion Shelly-Ann Fraser-Pryce ran her heat in the nearly empty Olympic Stadium in 10.84 seconds. Her Jamaican rival, defending Olympic champion Elaine Thompson-Herah, finished in 10.82. And Marie-Josee Ta Lou, the Ivory Coast sprinter who finished an excruciating fourth in Rio de Janeiro, kept saying “Wow! Wow!” after she crossed the finish line in a blistering personal best of 10.78.

“I’m in shock, actually," Ta Lou said. “But I know I’m ready.”

They were the fifth, sixth and seventh-fastest times of the year, produced on a day when seven of 54 sprinters hit a personal best — all in an opening round that's supposed to be designed more for shaking out cobwebs than watching the clock.

All that even though the field was missing this season's third-fastest runner, Sha'Carri Richardson, who is back home in the United States following a doping ban.

By comparison, only one runner, Fraser-Pryce, cracked 11 seconds in the opening round five years ago in Rio de Janeiro. She went on to win the bronze, behind Thompson (who has since gotten married) and American sprinter Tori Bowie.

“I mean, a lot of sprinters are dominating,” Thompson-Herah said.

Fraser-Pryce came in as the favorite for Saturday's final, which is already showing signs of living up to the hype. She ran a 10.63 back in June that has some thinking even Florence Griffith Joyner's 33-year-old world record could finally be at risk this year.

“Honestly, I have no idea,” Fraser-Pryce said when asked about the mark. “It’s super, super competitive. You want to make sure you focus on each round and the things you’re supposed to do.”

There were so many unknowns coming into the Olympics – namely if the year-long delay, the empty stadium or the stress of being cooped up in a hotel room in the lead-up to the Tokyo Games would hurt the athletes. The sprinters answered that with an emphatic “No.”

The first of 48 gold medals on the line over the next nine days was up for grabs later Friday in the men’s 10,000. Favorites include Jacob Kiplimo of Uganda and Selemon Barega of Ethiopia.

Other morning action on Day 1 went to form. Rai Benjamin of the United States and world-record holder Karsten Warholm of Norway cruised easily through their heats in the 400-meter hurdles, keeping a gold-medal showdown in the cards. Will it take another world record to win?

“Maybe someone else will do it,” Warholm joked. “I’ve done my job.”

Athing Mu, a contender in the women's 800, moved through the first round of her race and didn’t seem too bothered that the track announcer mispronounced her name. (For the record, it's pronounced “uh-THING moh”).

“I’m sure everyone saw my face,” the American said. “I don’t even know what he said. It was terrible.”

Ju'Vaughn Harrison made it to the high jump final, keeping alive the American's quest for a high jump-long jump double. Also advancing in high jump was world champion Mutaz Barshim, who wowed his home crowd two years ago when he won the world title in Doha.

With thousands of empty green, white and burgundy seats staring back at them, all the “oohs" and “ahhs” for this one came from the athletes themselves. After Round 1 of that women's 100, there was plenty to get excited about.

“It’s whoever gets to the line first wins,” said another contender, Blessing Okagbare of Nigeria, whose 11.05 felt ordinary on this day. "Sometimes it’s not about the time, but about the position.”

But sometimes, maybe this time, it could be about both.

American world-champion pole vaulter Sam Kendricks will miss the Olympics after testing positive for COVID-19.Kendricks’ dad posted on social media that his son had no symptoms but was informed while in Tokyo that he tested positive and was out of the competition.The U.S. Olympic and Paralympic Committee confirmed the news and said Kendricks has been placed in isolation at a hotel. He is being supported by the USOPC and USA Track & Field.Kendricks won the bronze medal at the 2016 Olympics and took gold at the last two world championships. He holds the American record at 19 feet, 10 ½ inches (6.06 meters).

TOKYO —

South Africa’s Tatjana Schoenmaker was the star of the day, setting the first individual swimming world record at the Tokyo Olympics.

Others shined, too.

Evgeny Rylov completed a backstroke double for Russia, Emma McKeon gave the Aussie women another gold, and China earned a return trip to the top of the medal podium.

The mighty Americans? For the first time in the meet, they spent the entire session Friday watching others win gold.

Schoenmaker, a 24-year-old South African, won the women’s 200-meter breaststroke with a time of 2 minutes, 18.95 seconds, breaking the mark of 2:19.11 set by Denmark’s Rikke Moller Pedersen at the 2013 world championships in Barcelona.

It was the third world record at the Tokyo Aquatics Centre, with the first two coming in women’s relays.

“I wasn’t expecting that at all," said Schoenmaker, who added to her silver in the 100 breast. ”It couldn’t have been a better race. It still just doesn’t sink in, maybe one day."

Rylov thoroughly snuffed out America's dominance in the backstroke, adding the 200 title to his victory in the 100 back.

Rylov won with an Olympic-record time of 1:53.29, while American Ryan Murphy wound up with the silver (1:54.15).

Murphy was a double-gold medalist at the 2016 Rio Olympics, where he extended an American winning streak that began at the 1996 Atlanta Games.

The U.S. won 12 straight men's backstroke events over six Olympics, but that streak ended with Rylov's victory in the 100. He made it 2-for-2 in the longer race, while Murphy settled for bronze and silver in the two events.

Britain’s Luke Greenbank grabbed the 200 bronze in 1:54.72.

McKeon touched first in the 100 freestyle with an Olympic-record time of 51.96, becoming only the second woman to break 52 seconds in the sprint.

Hong Kong’s Siobhan Haughey earned the silver in 52.27, while another Aussie, Cate Campbell, took the bronze in 52.52. American Abbey Weitzeil was last in the eight-woman field.

The Australians have won four individual women’s events at the Tokyo Aquatics Centre, in addition to setting a world record in a 4x100 free relay that included both McKeon and Campbell.

The team from Down Under has six golds overall, tied with the Americans, though the U.S. has the lead in the overall medal count.

The Americans won three medals Friday, also claiming the other two spots on the podium behind Schoenmaker.

But it was the first time the U.S. team went through an entire sessions of finals in Tokyo without winning at least one gold.

Lilly King set a blistering pace early in the 200 breast and held on for a silver in 2:19.92, adding to her bronze in the 100 event. Annie Lazor nabbed the bronze in 2:20.84.

“I don’t come from behind, that’s for sure, so I just wanted to put it out there and see where it goes,” King said. “I thought I did great.”

A day after winning its first two golds at the pool, China picked up another victory when Wang Shun touched first in the men’s 200 individual medley.

Wang edged Britain’s Duncan Scott with a time of 1:55.00. Scott took the silver in 1:55.28, while the bronze went to Switzerland’s Jeremy Desplanches in 1:56.17.

It was another disappointment for hometown star Daiya Seto, who didn’t even qualify for the final of his first two events. He got through in the 200 IM, but just missed out on a medal with a fourth-place finish -- a mere five-hundredths of a second behind the Swiss bronze medalist.

American Michael Andrew led after the third leg, powering to the top spot on the breaststroke. But he faded badly on the freestyle to wind up in fifth, more than 2 seconds behind the winner.

“I think it hurt worse than it looked, and it looked pretty bad,” Andrew said. “I knew I had to be fast at the 150 and I was praying for some Holy Spirit power to get me home in that (final) 50, but it wasn’t all there.”

But the U.S. has several good chances to claim gold over the last two days of the swimming competition.

Caeleb Dressel has two individual finals remaining, and Katie Ledecky is a big favorite in the 800 free.

Dressel set another Olympic record in the semifinals of the 100 butterfly.

Minutes after Hungary’s Kristof Milak took down the mark in the first semifinal heat, Dressel went even faster with a time of 49.71 in the second heat.

“I feel fine,” Dressel said. “I’m not worried about the schedule. I’ve had it written down for a couple weeks now. I know what’s coming. I know how to pace it correctly. I know how to take care of my body.”

It was the third-fastest time in history and left Milak as the second-fastest qualifier at 50.31.

In the preliminaries, Dressel tied the former Olympic record of 50.39 set by Singapore’s Joseph Schooling to win gold at the 2016 Rio Games.

Dressel will be a big favorite in Saturday morning’s final, though he could get pushed by Milak. The Hungarian already won the 200 fly with a dominating victory.

Dressel picked up the first individual gold medal of his career with a win in the 100 freestyle.

TOKYO —

Finally, a gold medal in Tokyo for Katie Ledecky.

FThe American star bounced back from the worst finish of her brilliant Olympic career to take the first-ever gold medal in the women's 1,500-meter freestyle Wednesday.

It wasn't quite the breeze that everyone expected in the metric mile. Ledecky built a big lead right from the start, then worked hard to hold off American teammate Erica Sullivan's blazing finish.

But it was Ledecky touching first in 15 minutes, 37.39 seconds. Sullivan claimed the silver (15:41.41), while the bronze went to Germany's Sarah Kohler (15:42.91).

It was quite a morning at the Tokyo Aquatics Centre for Ledecky, who seemed a bit overcome by the ups and downs she experienced in a little over an hour.

She tumbled over the lane rope to give Sullivan a hug, let out an uncharacteristic scream toward the American cheering section in the mostly empty arena and seemed to be holding back tears as she pulled her goggles back down over her eyes before exiting the pool.

In her first final of the day, Ledecky was blown away by her Australian rival, Ariarne Titmus, who made it 2-for-2 over the American with a victory in the 200 free.

Ledecky didn't even win a medal — the first time that's ever happened to her in an Olympic race. She was far behind all the way, never getting any higher than her fifth-place finish.

The Australian known as the Terminator gave the Australian women their third individual swimming gold with an Olympic record of 1:53.50, adding to her thrilling victory in the 400 free.

In the longer race, Titmus conserved her energy over the first half, then rallied to pass Ledecky with the second-fastest performance in history.

Ledecky?

She was nowhere to be found.

The defending Olympic champion made the first flip in seventh place and finished in 1:55.21 -- nearly 2 seconds behind the winner.

Siobhan Haughey of Hong Kong led much of the race before hanging on to take the silver in 1:53.92. The bronze went to Canada's Penny Oleksiak in 1:54.70.

"Obviously having a great swim in the 400 gives me confidence coming into the 200," Titmus said. "I thought my back end was definitely my strength in the 400. I knew I could have that on the way home in the 200."

Titmus wasn't all that pleased with her time, but it was good enough for another gold.

"Honestly, it's not the time that I thought I could do this morning, but it's the Olympics and there's a lot of other stuff going on," she said. "So it's just about winning here. I'm very happy."

Italy's Federica Pellegrini of Italy finished seventh in her fifth and final Olympics. She won the gold in 2008 and is still the world-record holder.

The Americans also picked up a couple of medals in the women's 200 individual medley — but not the one they wanted.

Japan's Yui Ohashi completed her IM sweep by beating Americans Alex Walsh and Kate Douglass, adding to her victory in the 400.

The winning time was 2:08.52. Walsh claimed the silver in 2:08.65, while the bronze went to Douglass in 2:09.04.

Defending Olympic champion and world record-holder Katinka Hosszu of Hungary finished seventh. She was the oldest swimmer in the final at age 32.

There were no surprises in the men's 200 butterfly, with Kristof Milak of Hungary romping to a dominating — but rather nerve-wracking — victory.

Milak won the gold by about two body lengths despite having to hastily change suits before the race, which cost him a chance to break his own world record.

Milak said that he realized about 10 minutes before walking on deck that his suit was damaged. He told Hungarian reporters that he totally lost focus, though it was hard to tell from his performance in the pool.

He held up the suit in the mixed zone, putting a finger through the tear before tossing it on a table in disgust.

Milak still touched in an Olympic record of 1:51.25 — more than a half-second off his 2019 world record (1:50.73) but some 2 1/2 seconds ahead of the silver medalist.

Japan's Tomoru Honda finished in 1:53.73, while the bronze went to Italy's Federico Burdisso (1:54.45).

South African star Chad le Clos finished fifth. He won the 200 fly at the 2012 London Olympics, upsetting Michael Phelps, but was no match for the Hungarian star.

Caeleb Dressel breezed through the semifinals of the 100 free, his first of three individual events. The American star posted the second-fastest time (47.23), just behind Russia's Kliment Kolesnikov (47.11).

"That's about what I expected," Dressel said. "It's going to be a fast final."

He shook off the view that he's a lock for the gold.

"I've never been a fan of favorites," Dressel said. "It's going to be a really fun race. Really looking forward to it. I mean, there's quite honestly eight guys in contention, so it's going to be exciting for everyone to watch. You guys (in the media) should be jealous I get to take part in it."

Olympic medalists can now remove their masks — briefly — on the podium after the International Olympic Committee relaxed its health rules.

Recognizing athletes want to smile and show emotion, the IOC is now letting them have 30 seconds of maskless time for photographs.

The IOC says this acknowledges “a unique moment in their sporting career.”

Health protocols agreed to ahead of the Tokyo Olympics to control COVID-19 infections had required all medalists to keep masks on for the whole ceremony.

The new maskless moments require athletes to stay on their own podium steps. Masks must be back on for group photos on the top step.

Tokyo organizers have reported 127 games-related COVID-19 cases, including 14 athletes, in Japan this month.

TOKYO —

The trouble started early. A step out of bounds on floor exercise here. A short landing there.

Over the course of two hours on Sunday, the mistakes — some almost imperceptible, some laid bare for the world to see — kept piling up, chipping away at the aura USA Gymnastics has built over the past decade. Not even the greatest of all time was immune to the realities of a sport where perfection is unattainable.

For 11 years, the Americans flirted with it, at least from a competitive standpoint, flying all over the globe, then flying back home with their suitcases stuffed with gold.

It still might happen at the Tokyo Olympics. But for the first time in a long time, it appears it won't happen without a fight.

Russia pulled off a stunner in qualifying, posting a top score of 171.629, more than a full point ahead of the U.S. total 170.562. While reigning Olympic champion Simone Biles topped the all-around with teammate Sunisa Lee close behind in third, the Americans ended their session looking up at another name on the scoreboard in the team standings for the first time since the 2010 world championships.

“This was not the finals,” U.S. high-performance director Tom Forster said. “This was getting into the finals. So this might be a great awakening for us and we’ll take advantage of it.”

China, France, Belgium, Great Britain, Italy and host Japan also advanced to Tuesday night's final. Olympic legend Oksana Chusovitina's journey is over. The 46-year-old from Uzbekistan did not qualify during the vault final at her record eighth Olympics.

Athletes, judges and administrators rose to their feet to salute Chusovitina as she made her way off the floor. She waved to the crowd with tears in her eyes before posing for pictures with whoever wanted one.

“I’m saying goodbye to sports,” Chusovitina said. “It’s kind of mixed feelings. I’m alive, I’m happy, I’m here without any injuries, and I can stand on my own.”

Something the Americans have done in the team competition for 10 years. After going largely unchallenged over two Olympic quads, they suddenly have company.

Forster raised eyebrows following the Olympic Trials last month when he said taking the top four finishers in the all-around in rank over a squad that could potentially score a bit higher by taking a specialist didn't matter. He reasoned sacrificing a tenth or two here or there wasn't going to matter based on the history of blowout wins by the Americans at world championships since he took over in 2018.

“We thought it was a good order, and I still feel good about it,” Forster said, who later added, “it will all work out.”

It always has since Biles joined an already dominant program in 2013. Everything will be reset for the finals, when the format changes to three-up/three-count. The pressure will be greater. And the Americans have found a way to thrive under it.

Inside a largely empty Ariake Gymnastics Center, they finally faltered. At least by their towering standards.

Not even Biles was immune.

While the 24-year-old star topped the all-around with a total of 57.731 and advanced to the finals in three events, it didn't come easy. She backpedaled all the way off the mat following a tumbling pass on her floor exercise, then basically did the same on vault. She responded with a solid set on uneven bars, but a spectacular beam routine ended with her temporarily reeling following her dismount, something Forster said he's never seen her do.

Biles, who came to Japan as the face of the U.S. Olympic movement and possibly the Games themselves, saluted the judges then walked off the podium with a smile that looked like a combination of relief, sarcasm and frustration.

There was plenty to go around.

Jordan Chiles' relentlessly consistent run that carried her to a spot on the team ended with a major mistake on bars and a fall on beam. Grace McCallum stepped out of bounds on floor. Lee had two of her scores (vault and floor) dropped in the team competition, though her electric bar set helped her surge into third behind Biles and Brazil's Rebeca Andrade.

The biggest bright spot for the Americans may have been the spectacular performance by Jade Carey. Competing as an individual after earning a nominative berth through the World Cup circuit, Carey earned a spot in the vault and floor exercise finals and only missed out on the all-around due to the rules that limit finals to two athletes per country.

Carey's decision to pursue an individual berth is symbolic of the depth the Americans have enjoyed during their rise to supremacy. Yet they no longer appear to have the market cornered on excellence.

ROC's performance's offered proof that the former gymnastics superpower is in the midst of a resurgence led by 21-year-old Angelina Melnikova. Even better, the Russians survived the balance beam relatively unscathed.

The 4-inch piece of wood set 4 feet off the ground has been the place where the country's gold-medal hopes have gone to die in recent years, yet there were no major issues during qualifying. The only serious miscue came when Lilia Akhaimova fell off during the end of an acrobatic series. No biggie. The Russians were allowed to drop her score.

Things will be different in the finals, when the margin for error disappears. While Melnikova stressed she didn't want to forecast what might with a medal on the line, she believes what has long been a walkover for the Americans will turn into something far more compelling.

“We hope that (we win),” Melnikova said. "We’re also going to struggle and fight. We have to. That’s the expectation for us.”

And suddenly, it looks doable.

TOKYO —

Related video above: Novak Djokovic shows off trophy after Australian Open win

Novak Djokovic’s bid for a "Golden Slam" is alive and well following a routine 6-2, 6-2 win over 139th-ranked Hugo Dellien of Bolivia in the opening round of the Tokyo tennis tournament.

The Tokyo Games mark Djokovic’s fourth consecutive Olympic appearance. He lost in an upset during the 2016 Olympic Games in Rio to Juan Martin Del Potro in the first round of the tournament.

The top-ranked Serb is attempting to become the first man to win all four major tennis tournaments and an Olympic singles gold medal in the same year. He's already won the French Open, Australian Open and Wimbledon this year. He still needs to take gold in the Olympics and win in the U.S. Open later this summer to complete the Golden Slam.

Steffi Graf was the only tennis player to accomplish the Golden Slam in 1988.

Djokovic’s next opponent will be 48th-ranked Jan-Lennard Struff of Germany.

Struff eliminated Thiago Monteiro of Brazil 6-3, 6-4.

After a yearlong delay caused by the COVID-19 pandemic, the Summer Olympics in Tokyo are officially open.

Japanese Emperor Naruhito declared the games open during the Opening Ceremony Friday at Olympic Stadium in Tokyo.

"I greet you all from the bottom of my heart,” Seiko Hashimoto, the president of the Tokyo Organizing Committee, told athletes at the official opening of the games.

“Today is a moment of hope. Yes, it is very different from what all of us had imagined. But let us cherish this moment. Finally, we are all here together," IOC President Thomas Bach said.

Tennis star Naomi Osaka later lit the Olympic torch, the symbolic opening of the 2021 games.

The Opening Ceremony took place in a mostly empty Olympic Stadium mostly devoid of spectators. Japan is in a state of emergency in the midst of a surge in COVID-19 cases.

First Lady Jill Biden and other world leaders are among the handful of spectators in attendance.

As per tradition, athletes from all participating filed into the stadium. The United States delegation arrived just after 9:30 a.m. ET, led by flag-bearers Eddy Alvarez, a baseball player, and Sue Bird, a basketball player.

Despite the lack of spectators, the program moved forward with typical theatrics, including a large-scale fireworks show.

The opening portion of the program focused on the themes of "apart but not alone," as a choreographed dance represented what it was like for athletes to come together after months of training solo.

The program also featured a moment of silence to honor those killed by COVID-19.

The performance is taking place just hours after the program's director, Kentaro Kobayashi, was fired after anti-Semitic jokes he made during a comedy set in the 1990s resurfaced.

The program's composer, Keigo Oyamada, also resigned in recent days after an interview he conducted in the 1990s resurfaced in which he boasted about bullying people with disabilities.

The Opening Ceremony is airing live right now on NBC. The network will re-air the performance tonight at 7:30 p.m. ET in an edited and "enhanced" primetime broadcast that features additional commentary.

Officials with the Tokyo Olympics say they will distribute condoms to athletes staying at the Olympic Village during next month's games — but are warning athletes not to use them until they return home.

The Olympic Village — full of young athletes from around the world visiting a new city for a short time — often earns a tawdry reputation for the level of promiscuity among its residents.

In a 2012 ESPN The Magazine story, athletes spoke about the after-hours goings-on at the Olympic Village.

"There's a lot of sex going on," said U.S. soccer goalkeeper Hope Solo, later estimating that "70 to 75% of Olympians" were having sex at the games.

Beginning in 1988, the International Olympic Committee began handing out condoms at the summer games in Seoul to reduce the spread of HIV. Since then, it seems that officials each year break the record of the number of condoms distributed to athletes.

At the last Summer Games in Rio de Janeiro, a local newspaper reported that officials distributed 450,000 condoms to athletes. USA Today reports that the prophylactics were available in green vending machines around the village.

Officials organizing the 2021 Games, slated to begin next month in Tokyo, say they will issue about 160,000 condoms to athletes — but they're asking athletes not to use them until they return to their home countries.

"The distribution of condoms is not for use at the athlete's village, but to have athletes take them back to their home countries to raise awareness" of HIV and AIDS issues," Tokyo 2020 said in a statement to Reuters.

Athletes at the 2021 games will face heavy restrictions in the hopes of limiting the spread of COVID-19, which is still spreading in largely un-vaccinated Japan.

According to NPR, officials will be monitoring athletes' movements via a contract tracing smartphone app. Outside of competition, athletes have been told to stay two meters apart from each other, even during meal times.

Athletes are also not permitted to leave the Olympic Village or accommodations unless they are headed to competition or to a pre-approved destination.

The IOC's decision to move ahead with the games has not been popular in Japan, where infectious disease experts have warned that hosting such a large event could lead to a surge in infections.