In-depth knowledge of the molecular response to physical exercise is now essential to define, for instance, if there is a maximum limit for the healthy practice of physical activity. This is becoming more and more relevant due to the increase in the number of people participating in demanding sport activities like marathons and other types of runs. Biomedicine has nowadays a new ally in this task, that is, the so called microRNAs, tiny RNA molecules that contribute to regulate gene expression, for instance, the ones expressed when we do exercise. Research carried out by researchers of the University of Oviedo, in charge of studying the relationship between these biomarkers and sport practice, has been awarded with the third prize of the 17th edition of the Sports Medicine National Awards.

Eduardo Iglesias Gutiérrez, professor of the Department of Functional Biology and coordinator of this study, explains that when we do exercise not only muscles react to this activity, but it also starts a complex network of communication between different tissues. In this situation, some microRNAs, especially those that are released into the blood flow, play an essential role, as they coordinate adaptation to exercise, recovery and even reparation of damage, if any.

It has been proved that, some of these circulating microRNAs are greatly useful in the diagnosis and monitoring of some heart diseases, whose diagnoses include other blood biomarkers. Interestingly, traditional markers increase above normal values after long-lasting physical exercise, like a marathon.

The aim of the awarded study was to analyze simultaneously the behavior of different traditional biomarkers and a group of circulating microRNAs in response to acute resistance exercises. Experts evaluated, more specifically, the expression of these markers in middle-age amateur runners who had at some point completed a 10-km run, a half marathon or a full marathon.

The analysis of the molecular response to physical activities becomes more important due to the unstoppable increase of people participation in marathons and popular runs

Eduardo Iglesias Gutiérrez highlights that the results prove that mainly aerobic exercises lead to an increase in the circulating cardiac biomarkers followed by a quick period of recovery in no longer than 24 hours, and he adds that this increase is proportional to the amount of the physical exercise performed. Researchers also noticed that this increase seemed to have no clinical relevance, especially considering the quick return to basal levels and the lack of symptoms showing cardiovascular disorders 72 hours after the run. In parallel, the results showed variations in both, the type and number of circulating microRNAs in each run. In addition, experts proved that these microRNAs were released steadily during exercise and thus they were part of the response of our organism to the physical activity. More specifically, the analysis carried out allowed them to identify that these circulating biomarkers could be related to regenerative process in our hearts.

The coordinator of this work emphasizes that the expression of microRNAs not only changes when we do exercise, but also with diets, that is why researchers had a strict control over the food eaten by the volunteers who took part in this study, not only before but also after the run.

From a practical point of view, the results of this work show that circulating microRNAs could play an important role in repairing limited cardiac damage induced by exercise, which opens a new pathway for the development of pharmacological modulators based on these microRNAs that simulate the effect produced by exercise. Nowadays, there are many research groups throughout the world working on pharmacological or dietary modulation of microRNAs aimed at the treatment of diseases and the improvement of population health. This study proves that doing exercise also modifies the expression of some circulating microRNAs and may perform a complementary task in this framework.

The project awarded is the result of the collaboration of several groups, including the participation of the University of Oviedo, the Institut d'Investigació Biomèdica Sant Pau of Barcelona, San Pablo-CEU University of Madrid, the IMDEA Food Institute of Madrid, the Spanish Agency for the Protection of Health in Sports and the Valle del Nalón Hospital.