Finger lengths predict marathon times

If you're planning on running a marathon anytime soon, rather than thinking only about your feet you might also want to take a look at your hands! New research shows that the relative lengths of the index and ring fingers can predict your race performance. Graihagh Jackson jogged over to see Cambridge University's Danny Longman to find out how...

Danny - Testosterone stimulates growth of the ring finger whereas oestrogen, the female sexual hormone, stimulates growth of the index finger. So, if you have a relatively longer ring finger to index finger, that would suggest you had a more masculine hormone exposure within the womb exposed to a higher concentration of testosterone.

Graihagh - I'm now looking at my ring and index finger and they're quite close. My ring finger is not too far away from my first finger in terms of length. So, that might infer what about me when it comes to long distance running then?

Danny - Well unfortunately, it wouldn't actually be possible to measure just by looking but if you were to have a relatively longer index finger relative to your ring finger, that would therefore give you a predisposition to be more successful at sports due enhanced efficiency in development of your cardiovascular system, which could result in faster running times.

Graihagh - So, how did you look at this? How did you test this hypothesis?

Danny - We attended a half marathon race in Nottingham. The runners had just completed a half marathon, they extremely hot, sweaty and tired and were entirely bemused by the idea of having their hands photographed. But...

Graihagh - I can imagine. 'Give me a flapjack and some Powerade!' would be my initial reaction, I think.

Danny - Well, that was the way we bribed them. I gave them some homemade flapjacks in exchange for photographing their hands.

Graihagh - What did you find? The people with the comparatively longer ring finger to their index finger, were they better runners?

Danny - Yes. We found that in both men and women, there was a strong correlation between the ratio of their fingers and their half marathon performances. Now, this correlation was particularly strong in men. We found that men who were exposed to a lot of testosterone in the womb were on average, nearly 25 minutes faster when compared to men who exposed to a little testosterone.

Graihagh - That's quite significant and what about women? Was it as pronounced?

Danny - Well, there was still a significant relationship for women. It wasn't quite as pronounced. Women with higher testosterone exposure showed an improvement of approximately 11 minutes.

Graihagh - People with a short ring fingers in comparison to their first fingers, should they just throw in the towel now?

Danny - Well, although we did find a very significant relationship between a relatively long ring finger, the amount of difference in ability of this is explained by this genetic factor, is absolutely minimal compared to the effects that you can achieve through training, through diet, through a healthy lifestyle. We really do want to stress that this should not put anyone off running.

Graihagh - So, the longer your ring finger, the better the run you are, perhaps. So, what does that mean?

Danny - When these findings are considered within the context of our evolution, they suggest that endurance running ability may signal male reproductive potential and genetic quality to women.

Graihagh - Do you mean that women just would have found long distance runners sexier?

Danny - From one point of view, but what this study is suggesting is that in ancestral populations, ability to run long distances in these populations, where hunting was an important method of acquiring meat, could be one of these signals for portraying genetic quality.

Graihagh - What do you mean? People used to run down their food? I thought it was all bows and arrows.

Danny - Well, we're talking, very much, a lot earlier in our evolutionary history. Now, this persistence hunting is a technique by which hunters track and chase prey to the point of prey exhaustion. Tribes in the Kalahari in Africa and also the Tarimoro in northern Mexico are able to track down prey in this way. So, what we're proposing and what our study is suggesting is that the ability to bring back the meat and to be a successful hunter displays to women traits that are desirable in a potential partners such as intelligence to be able to track the animal, athleticism to be able to catch it, but also in generosity because this meat is then shared throughout the community.

Graihagh - And given this, that we would've been doing this sort of behaviour, and still are in some places, it sort of seems that we've been evolved to run half marathons at least once a week. What's happened? Because most people can't run for 20 minutes without tearing a tendon or something terrible.

Danny - Well, one perspective to answering that question would be to say that our lifestyle today is not the lifestyle to which we have evolved to perform. Humans evolved in much more stressful environments than we have these days. The technology that we have developed over the last 50 years is increasing in pace exponentially and it's actually shielding us from the environment within which we evolved. And so, the environment in which we lived today is a lot more sedentary and as a result of that, the levels of fitness that we perhaps enjoyed in the past are not necessarily enjoyed by the vast majority of the population today.