Long distance runners are hot—scientifically speaking. It’s not just that running makes men fit and athletic: Long-distance running might be the mark, natural-selection-wise, of a high quality male, according to a new research, one that women would do well to select as a mate.
The study, conducted by the University of Cambridge’s Division of Biological Anthropology and published in the journal PLOS ONE, analyzed a group of 542 long distance runners (439 men and 103 women) who took part in the Robin Hood half-marathon in Nottingham, England, and they found that the best performing runners were likely exposed to higher levels of prenatal testosterone in their mother’s blood.
Prenatal testosterone exposure, which “androgenizes” the fetus, is also associated with traits such as stronger sex drive, higher sperm count and better cardiovascular efficiency in men. Bluntly speaking, better long-distance running skills might signal a higher quality male—at least in terms of reproductive fitness.
The scientists assessed this using the “2D:4D ratio”—the length of the ring finger versus the index finger, since people (both men and women) who have been exposed to higher levels of testosterone in utero have a longer fourth finger in comparison to the second. A positive correlation was found between the 2D:4D ratio and the race timing, indicating that more prenatal testosterone exposure resulted in a better long-distance runner.
While this was true for both men and women in the race, the advantage of more androgenized men was greater than that of more androgenized women: On average, the 10% of men with a higher 2D:4D ratio completed the race in 24 minutes and 33 seconds less than the 10% men with the lowest 2D:4D ratio, while the difference in women was just under 12 minutes.
While further research is still required to determine whether women respond to running as a signal of reproductive fitness, our evolutionary history suggests that women would have good reason to find runners attractive.
Hunter-gatherers used to maximize the human disposition for long-distance running to be better hunters, according to Danny Longman, author of the study:
You can still see examples of persistence hunting in parts of Africa and Mexico today. Hunters will deliberately choose the hottest time of day to hunt, and chase and track an antelope or gnu over 30 to 40 kilometers for four or five hours. The animal recovers less and less from its running until it collapses exhausted and is easy to kill.
Long-distance runners were better hunters, and hence better providers—which besides the physical and reproductive advantages associated with higher testosterone exposure, made them rather desirable mates. It might still have the same effect.