SWIMMING: Lia Neal, The Finisher
TRACK & FIELD: Allyson Felix, The Gazelle
GYMNASTICS: Gabby Douglas, The Returning Champ
If there's anyone who can stop Douglas from making a successful title defense in what some consider the glamour sport of the Olympics, it's Biles. At 4 feet 9 inches, the 19-year-old does some of the most difficult moves in gymnastics. She's so fierce that there's even a move named after her, The Biles, which is a double layout with a half twist. The reigning world champion is the first gymnast to have won the all-around title at three consecutive World Championships and is the first African-American gymnast to be an all-around world champion. Among Biles's many titles are her 14 World Championship medals—ten of which are gold, an amazing achievement in any sport.
GYMNASTICS, Simone Biles, The Flyer
WATER POLO: Ashleigh Johnson, The Slammer
WEIGHT LIFTING: Jenny Arthur, The Heavy
"When you meet me, I'm very nice and conservative. But when I get in the ring, my attitude changes and I'm there to win," says McPherson, whose explosive round kicks and spin kicks won her a bronze medal in tae kwon do at the 2012 London Olympics. She's the highest-ranked American in the welterweight division and eighth in the world. "I'm excited for Rio," says the 25-year-old. "I definitely think I can get the medal. I'm truly grateful to make the team, but that's not the end point. The end point is to win the gold."
TAE KWON DO: Paige McPherson, The Kick Master
Prescod (above left) has learned a lot since her first time at the Olympics, when she was eliminated in her first round. In fact, the next year, in Marseille, France, she became the first American woman ever to win a foil Grand Prix title. Now she's the second-highest foil fencer in the U.S. and the tenth in the world. "When I won the Grand Prix, something came together that made me beat all these people," says Prescod.
The Brooklyn native, 23, started fencing at 9 years old. Her single mother signed up Prescod and her sister for classes at the foundation of Peter Westbrook, a five-time Olympian and an Olympic bronze medalist. "It was to keep us occupied," says Prescod. "My mom wanted us to be involved in something very positive and productive."
She has certainly been that. Last year Prescod won an individual medal at the Senior World Championships, the first for an African-American woman. "Just doing that [winning the Grand Prix] gave me confidence that I can beat anyone in the world," she says. "It's in me to figure it out and put these things together to make it happen." Prescod, a Columbia University grad, goes to Rio—along with her fencing teammate Ibtihaj Muhammad (read Muhammad's inspiring story on page 66)—with renewed assurance.
FENCING: Nzingha Prescod, The Fighter
In 2012, at the London Olympics, Shields made history when she became the first American woman to win a gold medal in boxing. The then 17-year-old returned from the Games and achieved another goal: She became the first in her family to graduate from high school. Hailing from Flint, Michigan, Shields, now 21, lived a hard life and suffered abuse but never gave up hope. "Faith is one of the things I always held on to," she says. "When I felt like I had nobody, I always felt like I had God in my corner."
Shields started boxing at age 11, after her father introduced her to the sport. Having successfully defended her world champion title in May, she has a career record of 74–1 in the middleweight division. When she arrives in Rio, she will be ready to fight for another gold medal. Should she win, Shields would be the first American boxer, man or woman, to garner gold in successive Olympics. "I put my body through so much pain and through so much hard work," she says. "I've had to do this not only for me, but for my city, for my family and for my country."
BOXING: Claressa Shields, The Defender
LONG JUMP: Brittney Reese
As a sophomore at Stanford, Manuel, 20, has already broken the American and NCAA records in the 100-yard freestyle in swimming. At her first NCAA Championships, she anchored her team to a 400-yard freestyle relay win—and a new American and NCAA record.
SWIMMING: Simone Manuel
HIGH JUMP: Vashti Cunningham
The dynamic duo may be back, with defending champs Venus, 36, and Serena, 34, gunning for a third consecutive gold in doubles competition. While Serena looks to retain her singles title, it will be Venus's fifth Olympic appearance.
TENNIS: Venus And Serena Williams
The team members, led by cocaptain Tamika Catchings, 37 (in red), almost guarantee the gold medal. They have earned a record seven Olympic golds, one silver and one bronze. The team's record going into Rio is 58–3, which includes a 41-game winning streak.
BASKETBALL: USA Basketball
HEPTATHLON: Jessica Ennis-Hill (Great Britain)
It's hard to imagine how someone 5 feet 2 inches tall can vault over a bar that's 16 feet high, but that's just what Cuba's Silva is able to do. Don't sleep on her for a medal, if not gold.
POLE VAULT: Yarisley Silva (Cuba)
Her victory at the London Games meant Fraser-Pryce, 29, had won consecutive Olympic 100-meter races. She heads to Rio to tear up the history books and snag a third 100-meter title, which would make her the first woman ever to do so. But her stiffest competition might just be her countrywoman and training partner Elaine Thompson.
RUNNING: Shelly-Ann Fraser-Pryce (Jamaica)
RUNNING: Genzebe And Tirunesh Dibaba (Ethiopia)