RAQUEL DO CARMO SANTOS

A Practicing physical exercise brings countless benefits to human health, no one argues. A controversial aspect, however, is whether the duration and intensity of exercise contribute to increasing or decreasing appetite. It seems natural that the burning of energy leads to a greater need for food. However, a study with rodents carried out by physical educator Marcelo Benedito da Silva Flores, showed that in animals, an acute exercise session enhances the effect of the hormones leptin and insulin in the hypothalamus, an organ located in the region of the central nervous system and responsible for controlling functions. such as hunger, thirst and blood pressure, among others.

It is made of hormones in area that regulates hunger would be potentiated

Marcelo Flores subjected three groups of rats to six hours of swimming exercise, with a 40-minute break. Next, the researcher applied saline to one group of animals, and the hormones leptin and insulin to the hypothalamus of rodents in the second group – the third group was a control group and received nothing. The rats that received hormones showed an inhibition in the desire to eat, around 40% when compared to the control group. This inhibition lasted an average of 12 hours, considering the maximum exercise peak.

According to Flores, the results indicate that physical exercise directly interferes with the hypothalamus and appetite control. He remembers that leptin and insulin are anorexigenic hormones (reduce appetite) and are related to body weight control. But it was not known that physical exercise could enhance the effect of hormones, which would explain how its practice contributes to weight loss. Even the researcher, at the beginning of the work, did not expect to find these results.

During the research, Flores observed that exercise generated a series of metabolic, hormonal and neuronal signals that reached the brain. Among these factors, the study of interleukin 6 (IL-6), a molecular substance belonging to the cytokine class, was particularly interesting because it is released by the contracting muscle and interacts with other drugs administered to the animals' hypothalamus, enhancing their actions. . This was the key to the discovery, as it means that physical exercise modulated food intake.

The master's thesis, supervised by professor José Barreto Campello Carvalheira, had great repercussion in academia and was published in one of the most important scientific journals in the area, the American Diabetes (September edition). The work was also selected for oral communication at the American Diabetes Association Congress at the beginning of the year. Despite the paradigm shift, other studies need to be added to Marcelo Flores' work, aiming to find out, for example, at what quantity and intensity of exercise the same phenomenon would occur in humans. The experiment was carried out in the brains of rodents, which would make the study using this methodology unfeasible. A first step has already been taken.