Completing a marathon can be exhilarating but also agonizing. Thighs cramp. Backs ache. Toes bleed. Stomachs churn. Afterward, leg muscles can become so sore and tight that finishers must ease themselves backward down stairs and request assistance to rise from the toilet.
Yet, despite these aches and indignities, many of us who have finished a marathon will eagerly sign up later for another, to the occasional bafflement of friends or loved ones who saw us after the first race, peeling off bloody socks.
A new psychological study offers some explanation of why people do this, by finding that some marathon runners seem to develop selective amnesia, forgetting over time just how much they hurt. But the extent of that amnesia may depend on how much someone enjoyed the race.
Most of us know intuitively that pain is to some extent subjective. Cut yourself or pound your feet against the pavement for 26.2 miles and, objectively, you will feel discomfort.
But a wealth of psychological science has established that someone’s feelings at the time that an injury or ache occurs — the emotional context of the pain — can dramatically affect his or her sense of the pain. In general, pain associated with a positive experience tends to be perceived as less excruciating at the time than pain resulting from something rotten.
Our memories of pain likewise depend on the pain’s context. In a resonant study published earlier this year, Polish researchers polled women who had just undergone gynecological surgery or just given birth and asked them to rate the extent of their pain at that moment. All reported high levels of pain.
But, asked months later to recall that pain, the women who had undergone surgery consistently overestimated the amount and intensity of the pain they had felt after their operations, while the women who had given birth consistently underestimated the pain they had felt, especially if they had given birth vaginally. (Women who gave birth by cesarean section tended to remember somewhat more accurately.)
Our memories of pain are “influenced by the meaning” of that pain, the study’s authors concluded. Surgery, rarely a happy occasion, had led the women to amplify their recalled pain, while childbirth, presumably accompanied by joy, had caused the women conveniently to forget much of the pain caused by labor and delivery.
But whether exercise pain likewise is recalled inaccurately and whether such variations would tend toward dampening or intensifying the pain had not been closely examined. It could have implications for whether people stick to exercise routines, among other issues.
So for the new study, which was published recently in the journal Memory, Przemyslaw Babel, a professor of psychology at Jagiellonian University in Krakow and an author of the earlier study of childbirth and memory, turned to marathon runners.
He focused on the marathon because finishing one is unquestionably strenuous but also can be elating; the experience combines objective pain and subjective emotions.
The study’s method was simple. At the finish line of the 2012 Cracovia Marathon in Krakow, he asked 62 of the finishers to numerically rate the intensity and unpleasantness of the pain they were feeling at that moment, as well as their general emotional state.
The runners generally reported a moderate intensity and unpleasantness of pain at the time, averaging about a 5.5 on a scale of zero to 10.
Then either three or six months later, the same runners were asked to recall how much pain they had felt after the race.
Their memories proved to be quite different than their immediate experience of pain. Most of the runners, whether surveyed three or six months later, recalled the race as being much less agonizing than it had seemed at the time.
In fact, most recalled the intensity and unpleasantness of the pain as about a 3 on that zero to 10 scale.
Interestingly, those runners who had reported less happiness at the race’s end generally later remembered their pain more accurately than those who had been overjoyed after crossing the finish line, even if their pain at the time had been about the same.
The study was short-term and limited, of course, involving only marathon runners and not controlling for age, experience, overall health, personality or other factors.
But the findings do “help to explain why people run marathons again and again in spite of pain caused by such physical experience,” Dr. Babel said.
The selective amnesia associated with marathon running could have an evolutionary basis, he added, since early humans typically ran to survive and may have needed to disregard some of the associated discomforts.
The study also suggests, though, that not having fun may sharpen your recall of pain, which is unlikely to be motivating. So if you wish to maintain a strenuous workout or competitive program and also blunt the edges of your memories of any resulting pain, find an activity that you enjoy.