"Most of the girls think that sports are a man thing. I don't know why. Amantle has helped."

MAUN, Botswana - Victor Nkape's 12-year-old daughter was running around the family's cattle post here when he was struck by something that made the girl different.

His daughter was sprinting short distances, back and forth, over and over. Even more unusual, Mr. Nkape said, was the strength and intensity with which she ran.

"Your girl runs like a boy," Mr. Nkape's grandfather, standing nearby, remarked.

That was 16 years ago. Today that girl, Amantle Montsho, 28, is one of the fastest women in the world. The reigning world champion in the 400 meters, she is the favorite to win gold at the Summer Games in London.

Botswana has never won an Olympic medal in any sport. Should Ms. Montsho earn a place on the podium, her already pioneering role in this country of two million would be cemented.

"We used to chase the ostrich," said Kabelo Monnawalebala, 26, one of Ms. Montsho's stepsisters. "We'd play all day and race each other back and forth to school. I used to tell her she ran like a grown-up. We were happy."

Amantle Montsho is the only child of Mr. Nkape and Janet Montsho, who separated two years after her birth.

In her adolescent years, as she continued to run, Ms. Montsho grew increasingly lean and muscular, eliciting barbed jokes from classmates. Pako Seribe, a friend of Ms. Montsho's and an Olympic contender for Botswana in the men's 400 relay, said: "Women in Botswana are too scared to run. They like beauty too much. They don't want to be muscular."

Ms. Montsho, undeterred, continued to participate in local competitions, mostly running sprints like the 100 meters. She began attracting the attention of members of the Botswana National Sports Council.

At age 16, Ms. Montsho left school to work as a shop clerk, running in her spare time. But in Gaborone, the capital, the Botswana National Sports Council had the idea of pooling the Amantle Montshos from around the country into a program there for two weeks a month. Soon Ms. Montsho was often traveling the 8 to 10 hours from Maun to Gaborone.

The short sprints were not the best fit for Ms. Montsho's strength, said Raj Rathedi, one of her coaches. He helped guide her transition to the 400 meters. "She began to really show improvement," he said.

Her times continued to improve. She broke the national 400-meter record several times. It soon became clear that Ms. Montsho was outgrowing the Gaborone facilities, and she was given an Olympic Solidarity Commission scholarship, which financed her training at a facility in Dakar, Senegal. "I knew it would be hard," she said. "But I knew I had to train. I wanted to get better."

Ms. Montsho now has a sponsorship with Nike and earns prize money through races worldwide, including $60,000 for winning the world championships last summer - nearly four times the annual per capita income in Botswana. She finished eighth in the 400 at the 2008 Olympics in Beijing.

She has become an icon in her home country. A billboard showing her with the nation's flag stands above an industrial area. Editors at Mmegi, a newspaper based in Gaborone, said they had lost count of the number of times she had been on their front page.

"Amantle! She's our girl," Tshepang Olerato Tlhako, a 19-year-old in Gaborone, said. "She puts Botswana on the map and motivates us. Most of the girls think that sports are a man thing. I don't know why. Amantle has helped."

The next Amantle Montsho may rise from a similar setting. Mr. Nkape stood at his cattle post one recent Saturday morning with his daughter Bonnete, 10. One of Bonnete's chores is to run to get milk at the shop on the main road, about 500 meters away. When Amantle was young, she had the same task.

Mr. Nkape said he never timed either of them, but "Bonnete is faster than Amantle."

The New York Times