Hit a wall: Physiology and Psychology in the Marathon

　　Whether it is personal experience or the experience of skipping the battle happily, most people who have run a lifetime marathon will be familiar with the effect of “hit the wall”. For many people (including myself, sadly), it is the former rather than the latter. Hitting a wall at the end of the marathon may have a catastrophic impact on your overall completion time, which may take some time to restore physical and mental health. In this article, I will discuss the physical and psychological interactions during the critical period of the marathon, and provide some insights on how to prevent this painful experience!

　　Central fatigue

　　For physiologists, a marathon has always been a fascinating distance, and has long been considered a prime example of extreme sports. The deterioration of the running style at the end of the marathon strongly indicates that the muscle fibers are not optimally absorbed. A classic observation has shown that when the level of muscle glycogen drops to a critical level that requires a corresponding change in the activation strategy, running speed will drop significantly.

　　Although the mechanism and causes of peripheral fatigue development have been widely discussed before, people often overlook the role of central fatigue in performance degradation. The increase in the level of serotonin in the brain effectively reduces the body’s ability to protect itself. As a result, the central nervous system is damaged, leading to a voluntary decrease in muscle fiber recruitment.

　　Ross et al. (2007) is a study aimed at understanding the effects of long-distance running on the central nervous system (CNS). The study found that within 20 minutes after the marathon, voluntary muscle activation was significantly reduced, but disappeared after 4 hours, which indicates that the cortical output has changed (Rasmussen et al., 2007).

　　Central Governor Theory

　　There is evidence that the “central regulation” mechanism of the central nervous system can protect the human body from harm. Professor Timothy Knox of the University of Cape Town is famous for his research on this particular theory. He firmly believes that fatigue can be overcome, not so much a physical event as a feeling.

　　It is worth noting that the subjects did not consume any carbohydrates, which ruled out the possibility of carbohydrate metabolism leading to these improvements. This research strengthens Knox’s theory that the brain effectively limits our performance. The question is, can we persuade our “protective” brain to let us move forward? The answer seems to be yes, but the premise is that you have to be mentally prepared to survive the pain!

　　So the wall was just pushed down?

　　Although it is possible to “climb” to a certain extent, the answer is obviously “no”. There is a reason why the brain has proper protective mechanisms. Although it may have shown that we can extend the limit slightly, these findings do not mean that fatigue will never get better in our body. However, if you find yourself exhausted in the second half of the game, remind yourself that only by preparing for the last ounce of energy and working hard can you squeeze it out. After all, this may be different.