Namibian teenager Christine Mboma will be among the favourites to win a title at the World Athletics Under 20 Championships which start in Nairobi on Wednesday.
She also broke the world under-20 record for the third time in Tokyo, running the final in a time of 21.81 seconds.
Mboma's compatriot Beatrice Masilingi, who is also just 18, will compete in Nairobi having set a new personal best on her way to a sixth place finish in the women's 200m Olympic final.
Both Namibian athletes dropped down from their preferred 400m event after they were informed in July by World Athletics that their testosterone levels were beyond the allowed limit for female athletes to compete over that distance, unless they medically lower their testosterone for a period of at least six months.
According to World Athletics, Mboma and Masilingi are among 13 competitors from the Tokyo Games expected to participate in Nairobi.
Among the other African rising stars coming to Nairobi from Tokyo are Uganda's Prisca Chesang who runs in the women's 3,000m, Ethiopia's Bikila Tadese Takele who features in the men's 3,000m steeplechase and Nigeria's Imaobong Nse Uko who goes in the women's 400m.
The championships in Nairobi are starting a day later than scheduled, beginning on Wednesday 18 August and finishing on Sunday 22 August.
World Athletics says the decision was made because of the challenge that Covid has had on travel and logistics for overseas athletes.