Long-distance running great Vivian Cheruiyot insists she won't just be making up the numbers when she competes in a fifth Olympic Games this summer.

The 36-year-old will inscribe her name into sports history when she goes for glory in the women's marathon at the Tokyo Games on Aug 8 in Sapporo, 20 years after her Olympic debut in Sydney.

Cheruiyot will anchor the Kenyan team, which also features world-record holder Brigid Kosgei (2:14.04) and world champion Ruth Chepngetich.

While her two colleagues will be making their Olympic debuts, Cheruiyot will be aiming to bow out with marathon gold after appearances in Sydney (2000), Athens (2004), London (2012) and Rio (2016).

She had to wait until Rio to earn her first Olympic medal－gold in the 5,000m, followed by bronze in the 10,000m.

"Of course it was an honor to break into the Kenya team so young. I grew up dreaming of competing at the Olympics and never imagined I would make the Sydney Games. It was a great step for me and my career," Cheruiyot said on Tuesday.

Being picked for the all-conquering Kenya team is never an easy task, especially in the marathon. Yet even in the twilight of her career, Cheruiyot remains a force to be reckoned with, finishing second behind Kosgei at last year's London Marathon.

"To represent my country at all levels, and now in my sunset years, I am extremely happy that I have been able to tick all the boxes," Cheruiyot said.

"This gesture, the show of trust in my ability is special to me. I don't take it for granted. Making the Kenya team is the hardest part with so many young athletes emerging every day. But due to my discipline, hard work and commitment to the cause, I have made it. Looking back, I don't think I could be in the Kenya team waiting for my fifth Olympics if it wasn't down to good results."

Athletics Kenya president Jack Tuwei said Cheruiyot deserves her place in the team.

"Vivian is in a class of her own. She will go down as one of the best ever athletes of her generation. Besides Eliud Kipchoge in the men's category, she is exceptional," Tuwei said.

"It will be extremely difficult to get these kinds of athletes in future. Young kids rushing to the lucrative road races is the reason longevity in athletics is dwindling."

Kenya has named Sally Chepyego and Valary Aiyabei as its reserves.

Jemima Sumgong won marathon gold for Kenya at Rio 2016, but she was later banned from competition after testing positive for the drug EPO.

Tuwei is confident one of Cheruiyot, Kosgei or Chepngetich will retain the title for Kenya in Tokyo.