Why are triathletes so tough? Tel Aviv University researchers have identified at least one plausible explanation: They feel less pain than the rest of us.

The finding, published in the journal Pain, could open the door to new therapies for chronic pain in others.

"In our study, triathletes rated pain lower in intensity, tolerated it longer, and inhibited it better than individuals in a control group," said lead researcher Ruth Defrin. "We think both physiological and psychological factors underlie these differences and help explain how triathletes are able to perform at such a high level."
 

Triathletes are able to endure grueling competitions that combine swimming, bicycling, and running long distances without rest. They regularly push their bodies beyond the limits most of us can endure. But training and fitness alone don't account entirely for their athletic prowess, Defrin and her team found.
 

To reach their conclusions, researchers recruited 19 triathletes and 17 non-athletes to train for and compete in at least two triathlons per year — including the Ironman Triathlon, which combines a 2.4-mile swim, a 112-mile bicycle ride, and a 26.2-mile marathon run.
 

All the participants were put through a battery of physical and mental pain tests, involving the application of a heating device to one arm and the submersion of the other arm in a cold-water bath. They also filled out questionnaires asking about their pain.
 

The results found the triathletes perceived pain as less intense and were able to withstand it longer. The triathletes were also better able mentally tolerate the pain than non-athletes and were generally less fearful of experiencing discomfort.
 

One explanation for the differences: Triathletes may have taught their bodies to respond well to painful experience through their intense training — and push through it. But the TAU researchers said their study also suggests that psychology and physiology together enable triathletes to do what they do, which might help other non-athletes learn new techniques to help cope with pain.
 

"It is very difficult to separate physiology and psychology," says Prof. Defrin. "But in general, experience is the sum of these factors."