BEIJING—Jamaica, an island of 2.6 million people, has produced the fastest man and the three fastest women at the Beijing Olympics, and the explanations for the country’s success in the sprint races range from the power of root vegetables and reggae to genetic predisposition.

On Sunday, Shelly-Ann Fraser led a Jamaican sweep in the women’s 100-meter dash with compatriots Sherone Simpson and Kerron Stewart sharing silver after a photo finish.

The all-Jamaican podium came a day after another Jamaican, Usain Bolt, shattered his own world record as he left his rivals trailing in the men’s 100-meter dash. It was a weekend when Jamaica’s yellow, green and black flag flew with pride at the Bird’s Nest stadium.

Once known for being the land of laid-back reggae culture, Jamaica’s athletes are giving their country a new image as the island of power and pace.

A lot of people, however, are asking: What’s the secret of Jamaica’s champion sprinters?

Local yam

Bolt’s father credited the local yam for his son’s success. While that may raise smiles, there are a lot of people on the Caribbean island who believe their diet—full of root vegetables and herbs—is behind the pace of their youth.

“It’s part of the natural ability of Jamaicans, I don’t know, maybe it’s in the water,” Sports Minister Olivia Grange told Reuters when asked the question recently.

The popularly held idea among Jamaicans that they are born quick has been given some academic support by professor Errol Morrison of the island’s University of Technology.

Morrison told the Jamaica Gleaner newspaper that University of Glasgow researchers had found a special component, called Actinen A, found in the “fast twitch fibers” in muscles.

The gene is present in a disproportionately high number of Jamaicans and others of West African descent, according to Morrison.

“What it says to us is what is happening is not a flash in the pan, but there will be many potential Asafa Powells, Sherone Simpsons and Sherikas (Sherika Williams), because the genetic predisposition is there,” he added.

“The question is always there. What is it—nature or nurture—that makes us so good? The answer seems to be coming that there seems to be a strong underlying genetic or nature predisposition as to why we are able to perform like this.”

Power of reggae

The 21-year-old Fraser, however, credited the power of reggae and the inspiration of Bolt for the Jamaican sweep of the women’s 100-meter medals Olympics on Sunday.

“When I crossed the line and saw Sherone and Kerron there—that was the moment. I wouldn’t trade it for anything else,” she told reporters.

“Oh my God! That is too much. The secret of the team’s success—reggae power.”

Fraser said Bolt’s explosive world record run in the 100-meter dash on Saturday had also inspired her victory.

“Last night was amazing, it was crazy,” she said. “I wanted to come out and do the same thing.”

Power of tradition

There is also the power of tradition—athletics has long had strong roots in Jamaica.

Arthur Wint won the gold in the 100-meter dash at the 1948 London Games, the first Olympiad that Jamaica entered while still a British colony. Herb McKenley won four medals from 1948 to 1952.

There is also Jamaica’s female sprinting talent. Throughout the 1980s and 1990s, Marlene Ottey won multiple Olympic medals, although none of them were gold. Juliet Cuthbert won a silver in Barcelona in 1992.

Tanya Lawrence finished on the podium in Sydney in 2000 and now has a silver after winner Marion Jones’ medals were taken away from her for a doping offense.

Veronica Campbell-Brown won a bronze medal in Athens four years ago, but she was not able to make the 100-meter team for Beijing despite being the world champion.

There are also the Jamaican-born runners such as Linford Christie (Britain) and Donovan Bailey (Canada) who enjoyed Olympic success after moving abroad.

Combination of factors

The country has won a total of 46 Olympic medals—all but one of them in track and field.

“I think it’s a combination of factors,” Jamaican athletics chief Howard Aris told Reuters.

“We have the tradition from way back, from 1948. We have the talent, we have the certified coaches. From the very early stages, they are taught the right things—how to eat, how to train, how to sprint,” Aris said.

Whatever may be pushing Jamaicans to run fast, it is certainly working in Beijing.