Identical triplets from Estonia will make Olympic history when all three of them compete in the women's marathon at the Rio 2016 Olympic Games in August.

Luik triplets Estonia
Identical triplets and marathon runners triplets (L-R) Leila, Liina and Lily Luik pose for a picture in Tartu, EstoniaInts Kalnins/Reuters

They are hard to tell apart, even for their coach. The blonde, blued-eyed sisters from the southern Estonian university town of Tartu, now 30 years old, only took up serious distance running when they were 24. Liina got the sisters running, and after a couple of years they realised they were good enough to take part in international competitions.

They decided to try for the Olympics, adopting the slogan "Trio to Rio" to give shape to their hopes of all three competing in the Olympics. "After a year we had good results in Estonia and we thought we could achieve something good outside of Estonia and to do some big competitions like European Championships and the Olympic games," Lily told Reuters.

Luik triplets Estonia
(Left to right) Leila, Liina and Lily Luik pose for a picture after a training session in Tartu, EstoniaInts Kalnins/Reuters
Luik triplets Estonia
The Luik triplets work out in Tartu, EstoniaInts Kalnins/Reuters
Luik triplets Estonia
Leila, Liina and Lily Luik attend an interview in TartuInts Kalnins/Reuters

In competition, the sisters say they support each other emotionally and even in race tactics, such as taking it in turns to act as wind breakers. Having all but secured Estonia's three qualification spots for the marathon, they will make history as the first triplets ever to compete together at the Olympics.

The sisters live separately in Estonia and sometimes have to train apart. But they regularly spend winters together at a high-altitude training camp in Kenya, and they appear to enjoy each other's company, chatting away while running. They will all be training in northern Italy from June for Rio.

Luik triplets Estonia
Leila, Liina and Lily Luik pose wearing their 'Trio to Rio' T-shirtsInts Kalnins/Reuters
Luik triplets Estonia
The identical triplets play with a tech installation after a training session in TartuInts Kalnins/Reuters
Luik triplets Estonia
Liina Luik of Estonia talks to her sister Lily after they competed in the women's marathon at the 15th IAAF Championships in Beijing on 30 August 2015Dylan Martinez/Reuters

The sisters are not expected to end up on the podium at Rio. Kenya's Tiki Gelana set the Olympic record of 2 hours, 23 minutes and 7 seconds in London in 2012. The silver and bronze medal times were 2:23:12 and 2:23:29. By contrast, Leila, the oldest of the triplets, has the fastest personal best at 2:37.12, set in Shanghai in 2013. She is followed by Liina, whose personal best is 2 minutes and 30 seconds slower and Lily, the youngest, who is a further 45 seconds back.

However, all three said their goal for the Rio games was to finish together, to set personal bests and to finish with a smile. Asked by Reuters if they expected to bring home an Olympic medal, all three chimed in. "It would be great ... it's like our dream, and we know that we have to live in reality. It is very hard to compete against the Kenyan runners. We are not at the same kind of level as they are now, but in two or three years we can do that."