TARTU, Estonia >> As Lea Luik waited in a Soviet-era taxi, her husband, Henno, carried their newborns from the nursery. One, then two, then three.

In retellings, the punch line is always the taxi driver’s reaction: “Are you going to empty the whole hospital?”

The sisters Leila, Liina and Lily had been born a month premature. None weighed more than 4 1/2 pounds. For several weeks, home was an intensive care unit. Thirty years later, the sisters are Olympic marathon runners for this tiny Baltic nation — and they are believed to be the first triplets to have qualified for the Winter or Summer Games.

The Trio to Rio, the alliterative sisters call themselves as they prepare to run the women’s marathon in Rio de Janeiro on Aug. 14.

“We had to fight to survive when we were born,” Lily Luik (pronounced loo-EEK) said in a recent interview in this quiet university town with its floating saunas that putter down the Mother River. “We have this spirit to push hard.”

The International Olympic Committee said that it did not track siblings but that “various trusted sources reported it will be the first time that triplets compete at the Games.”

Among those sources is Bill Mallon, an American who co-founded the International Society of Olympic Historians and keeps a database of 12,000 Olympic athletes and their relatives. Two hundred sets of twins have competed at the Games, Mallon said, almost always in the same events, including the canoeists Pavol and Peter Hochschorner of Slovakia, who won gold medals in doubles slalom in 2000, 2004 and 2008.

But Mallon said he was “99.99 percent sure” that no triplets had ever participated in the same or in separate Olympics. “It’s rare enough that we would have heard about it,” he said. “This just doesn’t happen.”

It might seem rarer still to find elite triplets from a country like Estonia, which secured its independence from the former Soviet Union in 1991, has little tradition of female distance running and has a population of only 1.3 million — one of the smallest in the European Union.

Not until six years ago, when they were 24, did the Luik sisters even begin running seriously.

“It’s amazing that they will go to the Olympics in the same event,” said Harry Lemberg, who coaches the triplets. “It’s such a small country.”

Qualifying Times

Each nation is permitted a maximum of three athletes in each Olympic marathon. The Luik sisters qualified for the marathon standard of 2 hours 45 minutes. Leila has a personal best of 2 hours 37 minutes 11 seconds. Liina’s fastest time is 2:39:42, and Lily’s is 2:40:30.

Coincidentally or not, their order of career bests matches their order of birth.

These times do not compare to the Olympic record of 2:23:07, set by Tiki Gelana of Ethiopia when she won gold at the 2012 London Games. No Luik sister is expected to challenge for a medal in Rio. Still, Liina Luik finished 27th at the 2015 world track and field championships in Beijing with her fastest race and hopes to crack the top 20 in Brazil.

Lily Luik finished 38th at the world championships. Given Estonia’s slight history of female distance running, said Taavi Kalju, an Olympic historian, “It would be great if they finish in the top 50” in Rio.

Coaching triplets, Lemberg said, has its benefits and challenges. Marathon running is a solitary endeavor that can be lonely and isolating. The Luik sisters effectively make up a team that provides unfailing support and encouragement and the opportunity to test limits against familiar and uncritical rivals.

“Three together, we get so much energy from each other,” Leila Luik said. “No one wants to be the slowest. We push, push, push.”

Once shy, and reluctant to draw attention to themselves, the sisters are now ebullient and funny. They finish one another’s sentences and tell self-deprecating stories about their bottle-blond hair. (“We are really brown, like potatoes.”) Few can easily tell them apart, but as runners, the triplets do not have precisely the same speed or oxygen-carrying capacity. They do not recover in exactly the same way from strenuous training. In their alikeness, there is variance.

Understanding this, Lemberg now sometimes devises separate workouts for each sister. He said he took advice from Renato Canova, a highly regarded coach of German twins, Anna and Lisa Hahner, who are also scheduled to run the Olympic marathon in Rio.

“If you are together, you believe all the time, ‘My sister will help me,’” Lemberg said. “If you are alone, you are not taking help. You have to do it yourself. You are more of a competitor.”

The sisters say they understand. As girls, they experienced anxiety when separated at school. Now they live apart. They will turn 31 in October and will be forever close, but they are also adults living their own lives.

Liina spends much of her time with her boyfriend in Tallinn, the Estonian capital. Leila is engaged to be married. Leila and Lily are artists and have begun to sell their work, flowers and landscapes and portraits. And also swans, the English translation of their family name, which appear on coffee mugs and on their windproof running jackets.

“If you are alone, you have to make yourself keep an eye on your body and your rhythm,” said Liina Luik, who has swans tattooed on her forearm. “If you are together, maybe the stronger one does a little weaker than she should in a workout. Or the weaker sister overtrains.”

Lemberg is also sensitive to another aspect of coaching triplets. He speaks to them collectively, and individually, but he has a rule of not speaking privately about one sister’s training or health or personal life to another sister.

“If he speaks about me, it shouldn’t be to the others,” Liina Luik said. “We don’t like that.”

Olympic Race Strategy

In Rio, the sisters are tempted to pace one another, or to draft off one another if the day is windy, to experience the highlight of their careers in unison, identical triplets with identical results. But it is impossible to predict how a marathon will unfold. To achieve their best results they know they may have to run apart, not together.

As of now, Lemberg said, the strategy may be for Liina, who is in the best form, to run ahead while Leila and Lily run behind.

Leila and Lily laughed when told this and said they would yell at Liina, “Look out, the other two are coming!”

Liina Luik said she felt somewhat torn about how to run the Olympic marathon.

“As a sportsman in Rio, it is best to run your personal best,” she said. “If you think like a team or like sisters or with your heart, maybe the best way is to finish together. It’s good if we are together. But if I feel my personal best coming, I’ll go.”

Preterm birth and low birth weight are common among triplets. But, according to experts in pediatrics, by 1985, when the Luik sisters were born, Estonian doctors had begun to challenge the Soviet tradition that limited physical contact between mothers and their newborns in the hospital and kept fathers away entirely.

Some Estonian doctors advocated mothers breast-feeding in intensive care units and said mothers and fathers should have close, loving contact with their babies as soon and as often as possible after birth.

The Luik sisters became so active from a young age that their grandmother would tell their mother, “These girls don’t know how to walk; they just run.” Still, Lea Luik put her daughters into music lessons, preferring that they play the piano, the cello and the violin instead of taking part in sports. Even now, she said laughing, she does not want them to be marathon runners.

Lily Luik said, “She doesn’t think professional sport is normal for women. She thinks when we get older we’ll be in a wheelchair.”

Dancers to Runners

The triplets became professional hip-hop and show dancers after high school, taught dance lessons and appeared in a music video. They also worked as lifeguards, which required running as part of training. A colleague suggested that they try competitive running. In 2010, they sought a coach in Lemberg, who is chairman of the Tartu University Academic Sports Club.

By 2011, Liina and Leila Luik divvied up national titles at 10,000 meters, the half marathon and the marathon. Dancing seemed to help them as runners, Lemberg said, strengthening their ankles, straightening their posture, contributing to their whispery, economical strides.

“I thought they just wanted to be weekend runners,” he said. “After a year, I understood that they wanted something more serious.”

Estonian men have won two Olympic gold medals in track and field since the fall of the Eastern bloc. Erki Nool won the decathlon at the 2000 Sydney Games, and Gerd Kanter won the discus at the 2008 Beijing Games. But Estonia’s female distance runners have had limited international success.

The national women’s marathon record, 2:27:04, was set nearly two decades ago, in 1997, by Jane Salumae. Salumae won big-city marathons in Rome, Los Angeles and Vienna and took fourth at the 2002 European championships, but finished no higher than 44th in two Olympic appearances.

Perhaps, the Luik sisters said, their visibility will draw more Estonian women into distance running. A 7-kilometer run for women drew more than 10,000 participants in May in Tallinn. “We show that it is never too late to start a professional career,” Liina Luik said.

After Rio, the sisters will consider whether to continue toward the 2020 Tokyo Olympics. And, they said, they might challenge the world record, 2:15:25, held by Paula Radcliffe of England. But of course they were joking. Perhaps, they said, each could run a third of a marathon in a furtive relay, one jumping in for the other along the course with competitors not knowing the difference.

Leila Luik laughed.

“Maybe we hide in the bushes,” she said.

© 2016 The New York Times Company