Researchers think finger length reflects exposure to the hormone testosterone in the womb, the Telegraph reports.
The scientists at the Medical Research Council's Epidemiology Resource Unit, based at Southampton University, studied 241 boys aged 10 to 17 who took part in a sports talent-spotting competition in Qatar.
Each runner had their hands measured to see the difference between their ring fingers and index fingers.
They were then timed over a 50 metre sprint.
The results, published in the American Journal of Human Biology, showed those with longer ring fingers were faster at every stage of the race.
Dr John Manning, who led the study, said it's unlikely that boys exposed to higher levels of testosterone in the womb are simply stronger than their rivals.
Instead, they may owe their sporting success to better aerobic efficiency, the heart's ability to pump oxygen rich blood to hard-working muscles.
"We found finger ratios of the right and left hand were positively linked with sprinting times in boys,' said Dr Manning.
"The advantage they had was soon apparent after the start of the sprint and remained steady thereafter."
Previous studies have shown long-distance runners have the same feature.
But longer ring fingers have also been linked with everything from a lower risk of heart disease and exam success to male aggression and higher earnings in the workplace.