Los corredores del «maratón» no se esperaban, pero es reversible.

It is understood that Marathon A sports test with long endurance in which you need to travel 42 km and 195 meters at a constant pace, to be the first to cross the finish line in the shortest possible time. Its origin is in an ancient Greek legend.

These Sports events are usually massive, high in bodily demand and thousands of people can participate. They are held nationally and internationally in the world, and many of them allow athletes to qualify their country in this test during the Olympic Games.

Myelin is a Insulating layer, or sheaths, that form around nerves, including those found in the brain and spinal cord. It is composed of proteins and fatty substances. The myelin sheath allows electrical impulses to be transmitted quickly and efficiently in all neurons.

Myelin and Marathons

Marathon runners experience a decrease in the amount of myelin -A substance that surrounds neurons- in certain regions of the brain After a marathon, according to a study with ten participants published in Nature Metabolism and led by the University of the Basque Country (UPV/EHU). The effect was completely reversed two months after the race.

According to the authors, further research is needed to assess whether these changes have any effect on the neurophysiological and cognitive functions associated with these brain regions, but the study shows that most of the brain’s myelin is unaffected.

Long-term exercise forces the human body to rely on its energy reserves. Marathon runners, for example, primarily use carbohydrates like Glycogen as an energy source but switch to Fats when glycogen runs out in the muscles.

Myelin surrounds the surrounding brain neurons and acts as an electrical insulator consisting mainly of lipids, and previous rodent studies suggest that these lipids can act as an energy reserve in extreme metabolic conditions.

The team led by Carlos Matutes analyzed brain images taken by magnetic resonance imaging of eight male runners and two females before and 48 hours after the 42-kilometer race. They also took brain pictures of two of the runners two weeks later, and six runners two months later, as follows.

Less myelin in 12 areas

By measuring the amount of myelin, the authors found a consistent reduction in the content of this substance in 12 areas of white matter in the brain. These areas are related to motor coordination and sensory and emotional integration. After two weeks, myelin concentrations increased substantially and fully recovered two months after the marathon.

The researchers note that a limitation of the study is the small sample size and that evidence is needed in a larger cohort. Furthermore, further research is needed to establish How many extreme forms of exercise are related to the amount of myelin in the brain?.