Ultra-marathons: A painful affair
“Ultra-marathons are painful” sounds like an obvious statement, however, a recent study, published in the Scandinavian Journal of Pain is the first to show that running in an ultra-marathon actually results in greater sensitivity to pain.
By James W. Agnew and Steven B. Hammer
In the early 1970s the term “Runner’s High” gained popularity. It had been observed, and the research that soon ensued provided some evidence, that endurance runners felt a sense of “euphoria” while out on a long run. The original descriptions, in both the lay and scientific literature, included a description of elation, well-being, even feelings approaching religious ecstasy. A decrease in pain, however, was not included in the original descriptions.
What causes “Runner’s High”?
Endogenous opioids were first suggested to explain this sense of elation in runners. Since then the opioid explanation has fallen out of favor and endocannabinoids (a type of neurotransmitter we produce that binds to the same receptors in the body as marijuana) have gained support for causing this sense of bliss.
The term “Runner’s High” has been suggested to not only have been a major reason for the fitness fad in the late 1970s and early 1980s but also a major stimulus for research in the psychology and physiology of endurance exercise. It has undoubtedly been a positive force in drawing more people into participating in healthy endurance activities like running, biking, cross-country skiing, etc. With the continued and pervasive use of this term the idea of a decreased sense of pain has somehow become fused with this concept. This may have biased research concerning the important and obvious role of inflammation during exercise, especially the exercise of ultra-endurance competition. Inflammation has been shown and it is widely agreed to increase pain sensitivity. Inflammatory mediators have also been extensively shown to increase during ultra-endurance activities.
Pain decreases during exercise – at least in the beginning
Much of the research concerning changes in pain perception during exercise has been designed from the assumed premise that there is a reduction of pain during exercise. Thus virtually all of these related studies chiefly investigated the reasons for decreases in pain during exercise and this research has, in fact demonstrated that, over time, all types of exercise programs truly do reduce pain. Exercise regimens reduce the pain of subsequent daily bouts of exercise; there is reduced exercise pain in chronic pain conditions, and exercise reduces arthritic pain. None of these studies have investigated exercise lasting more than 30 minutes however. Ultra-marathons typically last from 5-6 hours to literally days.
At the finish of an ultra-marathon one can observe runners demonstrate incredible determination to reach the finish. They ignore all internal signals from their body to stop at the cost of potential injury. Many collapse at the finish. Their support team, composed of family and friends, gather about them to aid and comfort. They have done so throughout the race and now at the finish they will continue to aid them while they recover. You can watch them for usually hours after they finish as they await the awards ceremony that is typically 32 to 36 hours after the start of the race. They often cannot hold food or drink down because of gastrointestinal upset. Although they are desperately tired, they cannot sleep. Just to take a few cautious steps is excruciatingly painful. They may very well be hallucinating but nothing approaching euphoria can be observed, other than being infinitely pleased that they are done running. These athletes are in pain.
Subjective vs objective pain assessment
Research, largely over the past four decades, has yielded a tremendous amount of exercise-related data for all sorts of modes, conditions and intensities of exercise across age, gender and genetic groups. Exercise-pain data, however, is surprisingly lacking from the scientific literature. This is at least in part due to the subjectivity of pain. A well-known clinical definition by Margo McCaffery describes pain as “whatever the experiencing person says it is, existing whenever the experiencing person says it does”. However, researchers are now gaining objective measurement techniques for the assessment of pain responses that will allow them to explore pain mechanisms more effectively during different situations including exercise.
More and more ultra-marathon runners but not enough data
Data is lacking in the new ultra-endurance athlete population, which continues to grow exponentially. According to statistics by the German Ultra-marathon Association the number of participants in various ultra-marathons has increased from 43,699 in the year 2000 to 315,620 worldwide in 2017. More data is required for this growing population when considering the probability of injury and even death when participating in the extreme rigors of an ultra-endurance event. This is worrisome considering the increasing numbers of participants in these events.
In a recent study published in the Scandinavian Journal of Pain ultra-marathon runners were now shown to have decreased pain thresholds and a decreased ability to inhibit pain by the brain (thus a greater sensitivity to pain). Existing research demonstrating the beneficial, anti-inflammatory effects of exercise, that decreases our sensitivity to pain, confirms the importance of including routine exercise in one’s daily lifecycle. James W. Agnew and colleagues from Indian River State College in Fort Pierce, Florida, however, emphasize that “our body’s anti-inflammatory responses only occur because we initially have inflammation – the kind of pain-causing inflammation that occurs during the extreme exertion of an ultra-marathon.”
Read the original article here.