A new study from Israel finds that triathletes feel less pain than casual exercisers. If further research shows that intense training has given them this ability, then it could be a way to treat chronic pain sufferers.
Triathletes train and compete in a gruelling mix of three endurance sports: swimming, cycling and long-distance running, without rest. They push themselves beyond what most of us can endure.
However, we know very little about what gives them these abilities. That is, until two physical therapy researchers at Tel Aviv University decided to investigate and propose a possible explanation, which they report in the journal PAIN.
Senior researcher and professor Ruth Defrin summarizes their findings:
“In our study, triathletes rated pain lower in intensity, tolerated it longer, and inhibited it better than individuals in a control group. We think both physiological and psychological factors underlie these differences and help explain how triathletes are able to perform at such a high level.”
For their study, Prof. Defrin and her doctoral student Nirit Geva recruited 19 triathletes and 17 non-athletes.
The triathletes were at a level where they trained for two or more triathlons per year, including the Ironman triathlon, a notoriously tough challenge where contestants swim for 2.4 miles, then cycle 112 miles and then run a 26.2 mile marathon, without a break.
The non-athletes did non-competitive exercises at a lower level, such as swimming, jogging and aerobics.
Both groups underwent psychophysical pain tests that measured, among other things, pain threshold, pain tolerance, and pain intensity.
The tests included having heat applied to one arm while the other was put in a bath of cold water. This measures condition modulating pain (CPM), or the ability of the individual to ease one pain in response to another.
The participants also completed questionnaires about their attitude to pain, such as fear and amount of perceived stress.
The results show that the triathletes and non-athletes identified pain to the same extent, but the athletes perceived it as less intense, and could withstand it longer.
As well as showing higher pain tolerance, the triathletes also rated pain as less painful and had lower fear of pain values.
Additionally, triathletes had much higher CPM, and the higher this was, the lower their fear of pain and perceived mental stress during training.
The authors conclude:
“The results suggest that triathletes exhibit greater pain tolerance and more efficient pain modulation than controls, which may underlie their perseverance in extreme physical efforts and pain during training/competitions. This capability may be enhanced or mediated by psychological factors, enabling better coping with fear of pain and mental stress.”
They explain that detecting pain is just a straightforward sensory process, but then a number of factors are involved in evaluating the pain. These include attitude to pain, motivation, and life experience.
They found that compared with the non-athletes, the triathletes reported worrying about and fearing pain to a much lesser extent, and this could explain their higher tolerance.
Previous studies have also found that psychological manipulation can affect pain perception.
Another reason the triathletes showed lower ratings, higher tolerance and better regulation of pain could be that they have taught themselves, through their intense training, to respond powerfully to pain sensations.
The researchers suggest, with reference to other studies, that the psychology of pain is wrapped up with the physiology: it is the combination that enables triathletes to do what they do.
Prof. Defrin says:
“It is very difficult to separate physiology and psychology. But in general, experience is the sum of these factors.”
They now want to do more research to address the “chicken and egg” question and find out if triathletes do what they do because they feel less pain or they feel less pain because of what they do.
If they find the answer is triathletes feel less pain because of their intense training, then this could be a starting point for treating people with chronic pain.
Chronic pain sufferers are in a similar situation to triathletes in that they suffer pain every day, but unlike triathletes, their pain has the opposite effect – it weakens rather than strengthens their ability to inhibit it.
Research led by the University of Oxford in the UK that was published in Biological Psychiatry in 2010, found that depressed mood increases pain perception.