There have been some quite interesting studies relatively recently showing that athletes have higher pain thresholds, on average, than the general population.  In the laboratory, athletes generally report a noxious stimulus as being painful at a higher intensity when compared with a ‘normal’ control group and those individuals are also able to tolerate the painful stimulus for longer when compared with more sedentary individuals.

Some studies have also looked at different types of athletes to see if there were any differences in pain perception between sporting populations.  Perhaps not surprisingly, endurance athletes have better pain tolerance (they can put up with experimentally induced pain for longer than strength based athletes), whereas the strength based athletes have higher pain thresholds (they did not report pain until higher intensities of a painful stimulus were applied).  This makes sense given what they have trained their brains to endure.

But what does this mean for the general population?  And what does it mean for the significant proportion of adults in the UK who suffer from persistent pain?

Well, if you extrapolate these findings to the general population we would say that generally ‘exercise and movement is king’ when it comes to improving your brain’s ability to modulate the pain we perceive from a given sensory input.   When you are doing something really physical and need to carry on just that little longer, even though your lungs are bursting and your muscles are on fire, the trained brain has learned that, whilst this is perhaps an unpleasant feeling, it is not necessarily related to harm and that you can continue doing what you are doing, at least to some degree, without any negative consequence.  The training adaptation is physiological - your muscle chemistry will change and your heart and lungs become ‘fitter’ - but your central nervous system also adapts by learning that we should not fear this type of unpleasant sensation.  

At the other end of the scale, in patients with long term pain, a graded exposure to movement and slowly increasing the intensity of exercise over time creates a positive experience, one that results in the brain being more accepting of similar future experiences.  By contrast, if patients do not pace themselves properly, a negative experience might result which would be likely to reinforce a future protective response i.e. increased pain, autonomic activity (increased muscle tone) and continued anxiety about movement and subsequent avoidance of exercise. As long as patients pace themselves sensibly, movement should reinforce a learning effect that allows the brain to interpret what is actually a normal sensory input as non-threatening, rather than one that relates to danger and being potentially harmful.  

Patients with persistent pain often experience little flare ups in their recovery journey even though they may be generally improving and will invariably say that they must have over done it somehow. However, when you question them about this they do not recollect anything strenuous enough to be responsible for a tissue ‘injury’.  We ensure that they understand the difference between ‘overdoing’ it physically i.e. too much force and therefore something has strained or become harmed in some way, and overdoing it in terms of exceeding their nervous system tolerance.  We teach them that they have an overly protective central nervous system (brain) and so pain registers with a very low level of sensory input, long before they are anywhere near the level of physical force required to do actual harm.

This makes guiding patients through increasing levels of movement effort a difficult balancing act.  A good pain coach, someone who is experienced in dealing with clinical neuroscience, is certainly something that patients with persistent pain, or athletes who want to find their true limits, should invest in.