Delayed one year by the coronavirus pandemic and potentially affected by this week’s high temperatures in Tokyo, the Olympics’ track and field schedule is still expected to feature record-breaking performances.

With 48 medal events starting Saturday morning, track and field has the busiest schedule. The top athletes in the U.S. sealed their bids during the Olympic trials in Eugene, Ore., last month, and they’ll match up with a number of international athletes with chances to break world records.

Here’s a full breakdown of the top contenders to watch this week:

U.S. track athletes

Rai Benjamin

A 23-year-old who attended the University of Southern California, Benjamin is already one of the greatest 400-meter hurdlers of all time. He still must prove he is the best in Tokyo. Norway’s Karsten Warholm downed Benjamin at the 2019 world championships. A week after Benjamin came within five hundredths of a second of breaking Kevin Young’s 29-year-old world record, Warholm did break it at a Diamond League meet, lowering the mark to 46.70 seconds. To win gold, Benjamin or Warholm will probably have to break the record again.

Matthew Centrowitz

After becoming the first American man to win a gold medal in the 1,500 meters since 1908, Centrowitz returns still at peak form. At 31, Centrowitz is an old man at the distance — even back in 2016, he wondered if he would have to move up to 5,000 meters for the next Olympics. But he finished second by a hair to 20-year-old Cole Hocker at the Olympic trials. He may not be the fastest, but he has become one of America’s greatest middle-distance runners through tactical savvy that borders on sorcery.

Allyson Felix

The only American track and field athlete with 10 medals is Carl Lewis. Felix could catch, or even surpass, Lewis in her fifth and final Olympics. Felix made the U.S. team in the 400 meters at age 35, less than three years after giving birth to her daughter, Camryn, via an emergency delivery that threatened both mother and child. Felix owns nine Olympic medals, six of them gold. Felix could also be chosen for the 4x400 relay, where the U.S. team would be a heavy favorite.

Keni Harrison

Harrison entered the 2016 Olympics as the newly minted 100-meter hurdles world record holder — but she didn’t even compete in Rio de Janeiro, having finished sixth at the U.S. trials less than a month before running 12.20 seconds, a time that still stands. The Americans swept the medals in Rio and could do so again in Tokyo. This time, at 28, Harrison will be there. She will be looking for her first major international title, having won silver at the 2019 world championships and finishing fourth in 2017.

Grant Holloway

Another world record threat going to his first Olympics, Holloway came within one hundredth of a second of breaking Aries Merritt’s world record of 12.80 seconds in the 110-meter hurdles at the trials — in a semifinal heat. Jamaican rival Omar McLeod failed to make the Games, but the push Holloway will receive in Tokyo could vault him toward a new world standard. It would be his second world record this year, adding to the indoor 60-meter hurdles record he set in February.

Isaiah Jewett

Clayton Murphy won the 800 meters at the trials and won bronze at the 2016 Games, but the most electrifying presence in the two-lap race that knocked favorite Donavan Brazier out of the Olympics was Jewett. One week after winning the NCAA championship for USC, Jewett set a wicked pace on the first lap, created a gap and had just enough stamina to hold on for a spot in Tokyo. Jewett’s zeal for racing is infectious. With a month of rest after a long college season, it will be worth watching whether he can repeat his trials surprise and land on the podium.

Erriyon Knighton

Three years ago, Knighton was a high school football player with designs on earning a scholarship in that sport, and he took up track to improve his already explosive speed. He has no plans to ever play football again. At the Olympic trials, Knighton broke Usain Bolt’s 17-year-old junior record by running the 200 meters in 19.84 seconds and became the youngest Olympian since Jim Ryun in 1964. He turned professional in January, just before his 17th birthday, and is far ahead of schedule.

Noah Lyles

He may have lost his goal of three gold medals when he did not qualify in the 100 meters, but Lyles remains one of the most electric figures in sprinting. The Alexandria, Va., product and alum of T.C. Williams High reestablished himself as the gold medal favorite in the 200 after a trying year by winning the trials in 19.74 seconds. He is the fourth-fastest man ever at the distance, which makes him a likely choice for the men’s 4x100 team, the other event in which he is a reigning world champion.

Sydney McLaughlin

McLaughlin turned 17 during her first Olympics in Rio, where she gained experience but only reached the semifinals. She will enter her second as the newly minted world record holder in the 400-meter hurdles, having run it in 51.90 seconds at the Olympic trials, becoming the first woman to break 52 seconds in front of former record holder Dalilah Muhammad, who continues to challenge her. With the help of legendary coach Bob Kersee, McLaughlin is pushing her event forward. Women have long been taught to take 15 strides between hurdles, but McLaughlin has started taking 14, raising the ceiling on what times are possible.

Athing Mu

Growing up in a track-crazed family in New Jersey, Mu started breaking youth records in her early teens. She hasn’t stopped. Mu set a collegiate record in the 400 this year at Texas A&M, then turned professional immediately after her season ended with multiple NCAA titles. At the trials, she blew away a strong field in the 800 meters, finishing acres ahead of a pack that included American record holder Ajee Wilson. Mu could be picked to run the 4x400, giving her two strong chances at gold medals in her first of probably many Olympics.

Gabby Thomas

It wasn’t a surprise that Thomas made it to Tokyo, but it was stunning how she pulled it off — by running 21.61 in the 200 meters, making her the second-fastest woman ever at the distance, behind only Florence Griffith Joyner. Thomas, 24, balances her accomplishment with an equally impressive life off the track. She graduated from Harvard with a degree in neurobiology and is now studying for her master’s degree in public health, with an emphasis on epidemiology.

U.S. field athletes

Ryan Crouser

If Crouser wins his second consecutive Olympic gold medal, it still may be only his second-best accomplishment this year. At the U.S. Olympic trials, Crouser broke Randy Barnes’s 31-year-old shot put record by heaving the 16-pound iron ball 23.37 meters (76 feet 8¼ inches), the longest throw ever by almost 10 inches. Crouser’s best competition will probably come from countryman Joe Kovacs, who beat him at the 2019 world championships.

JuVaughn Harrison

Any performance that evokes the name Jim Thorpe warrants notice. At the Olympic trials, Harrison became the first American man since Thorpe to claim a spot in both the high jump and long jump at the Olympics. Harrison, still competing in his LSU track suit, jumped 27 feet 9½ inches in the pit and 7 feet 7¾ inches over the bar to win both events.

Deanna Price

A hammer thrower who joyfully — and often comically — wears her emotions on her sleeve, Price has emerged as one of the best in the world, winning the 2019 world championship and only improving since. She became the second woman to break 80 meters (87.4 yards) at the U.S. Olympic trials, where she also broke her own American record. Price could give the United States its first Olympic medal in the event, which women have contested at the Games only since 2000.

International track athletes

Dina Asher-Smith, Britain: Just 25 and already the fastest British woman in history, Asher-Smith made her Olympic debut at just 20 years old, finishing fifth in the 200-meter final in Rio and winning bronze as part of Britain’s 4x100 relay. She has much greater aims in her second Games. Asher-Smith is ranked first in the world in the 200 and second in the 100. She won three medals at the 2019 world championships, claiming gold in the 200 while reaching the podium in the 4x100 and 100.

Timothy Cheruiyot, Kenya: Cheruiyot, 26, finished second and first in the 1,500 meters at the past two world championships, and now he will run on the Olympic stage for the first time. At a Diamond League meet in July, Cheruiyot became the fastest 1,500-meter runner in the world this year and the seventh fastest of all time by running 3 hours 28 minutes 28 seconds. Five of the seven fastest men ever at the distance are Kenyans, but Cheruiyot is the nation’s best hope to win Kenya’s first Olympic medal in the event since Asbel Kiprop’s gold in 2008.

Letesenbet Gidey, Ethiopia: In June, Gidey ran 10,000 meters in 29 minutes 1.03 seconds, breaking the record Sifan Hassan of the Netherlands had set two days earlier. Their showdown could be one of the best in Tokyo. Gidey, only 23, will be appearing in her first Olympics two years after winning a silver medal in her first world championships, where she finished behind only Hassan.

Shelly-Ann Fraser-Pryce, Jamaica: With Usain Bolt in retirement, Fraser-Pryce has picked up the mantle as Jamaica’s greatest sprinting star. At age 34, she will try to join Bolt as the only sprinters to win three Olympic gold medals in the 100 meters. Fraser-Pryce is both the fastest woman in the world this year in the 100 and the second fastest at 200 meters, the distance at which she won silver in 2012.

Shaunae Miller-Uibo, Bahamas: Miller-Uibo delivered one of the lasting images of the 2016 Rio Games, diving at the line to beat Allyson Felix by 0.07 seconds and win the 400-meter gold. A towering and graceful runner, Miller-Uibo would be considered a threat to win in both the 200 and 400 this year, but the schedule does not allow for the double. Miller opted to run the 200, a distance at which she is unbeaten this season. The decision means she will miss out on a rematch against Felix, who made the U.S. team only in the 400.

Karsten Warholm, Norway: The only thing keeping Warholm, 25, from being considered the best ever at the 400-meter hurdles is an Olympic gold. He has not lost in the event since the fall of 2018. He has two world championships. This month, he broke Kevin Young’s 29-year-old world record by finishing in 46.70 seconds. And yet, the presence of Rai Benjamin of the United States and Abderrahman Samba of Qatar — the third- and fourth-fastest men ever in the event — means Warholm will probably have to break his own world record to win gold at his first Olympics.

Wayde van Niekerk, South Africa: After he broke Michael Johnson’s 17-year-old world record in the 400 meters at the 2016 Olympics by finishing in 43.03 seconds, van Niekerk’s road to superstardom hit a snag. He tore his ACL in a 2017 charity rugby game, knocking him out of the world’s elite for several years. His comeback hit a promising note when he ran 44.56 seconds in June, the 10th-fastest time this year. He’ll have to deal with American superstar Michael Norman and burgeoning threat Randolph Ross, but van Niekerk could use the Tokyo Olympics as a chance to announce his return.

International field athletes

Mutaz Essa Barshim, Qatar: Having won silver and bronze at the past two Olympics, this might be Barshim’s last, best chance at high jumping gold. He has finished no lower than fourth in the past five major international events, resulting in two world championships, one world championship second place and those two Olympic medals. American star Vashti Cunningham likes to study Barshim’s fluid style.

Mondo Duplantis, Sweden: No athlete in the world stands further apart from his peers than pole vaulter Duplantis, a 21-year-old heading into his first Olympics. In February 2020, Duplantis broke Sergey Bubka’s world record by vaulting 6.18 meters (20 feet 3¼ inches). Since the start of 2019, no one other than American Sam Kendricks, the reigning world champion who was forced out of the Games after arriving in Tokyo because of a positive coronavirus test, has vaulted higher than 6.06 meters. Duplantis was born and raised in Lafayette, La., to an American father of Cajun descent and a Swedish mother, but Sweden offered a more certain path to the Olympics and greater financial incentives.