The joy of the race, that sense of well -being, the freedom and the extra energy that the runners often show us, is not just a question of endorphins. A new study shows that “the Euphoria of the runners” is a phenomenon also caused by dopaminean important neurotransmitter for motivation.
This is, in substance, what has been shown by a study conducted at the University of Montreal Hospital Research Center (Crchaum) and published in the Metabolism magazine.
“We discovered that the rewarding effects of physical resistance activities (marathon) are modulated by leptina key hormone for the effects on metabolism. Leptin inhibits physical activity through dopamine neurons (dopaminergic) in the brain, “explained Stephanie Fulton, researcher at the Crchum.
“Secreted by adipose tissue, leptin helps to control the feeling of satiety. This hormone also influences physical activity.” The fatter there is, the more leptin there is, the less we need to eat.
Our results now show that this hormone also plays a fundamental role in Motivation of the racewhich, in turn, can be related to the search for food, “explained Stephanie Fulton, who is also a professor at the University of Montréal’s (Department of Nutrition).
“The hormonal signals that modulate nutrition and exercise is believed that they are closely connected. The ability to perform the physical activities of endurance (resistance race – marathon) of mammals, in particular of human beings, it is thought that they have evolved to maximize the possibilities of finding food.
This study suggests that the leptin It plays a fundamental role, both in regulating the energy balance and in encouraging the behaviors that are “rewarding” for the person’s metabolism, that is to say, engage in physical activity to find food.
The researchers studied these phenomena in laboratory mice that voluntarily run in a cage. These mice can perform up to 7 kilometers per day. In the laboratory, the physical activity of normal mice was compared with that of mice subjected to a genetic modification to suppress a molecule activated by leptin, called stat3.
There Stat3 molecule It is found in the neurons that summarize dopamine in the mesencephal (an important part of the central nervous system). And the neurotransmitted signals follow one another creating a motivational way in the brain.
“Tops that do not have the Stat3 molecule, in dopaminergic neurons, run more. On the contrary, normal mice are less active, because leptin activates the Stat3 molecule In dopaminergic neurons, indicating that energy reserves in the body are sufficient and that there is no need to do physical activity and go in search of food, “explained Maria Fernanda Fernandes, the first author of the study.
“And Leptina is important for the motivation of the activity also in humans? Yes” – confirms Fulton. “Studies have clearly demonstrated a correlation between Leptina and running times In the marathon ” – he continues -“ And the lower the circulating levels of leptin, the better the performance in the race. Our studio on mice suggests that this molecule is also involved in the rewarding effects when we make exercise. “
We hypothesize, therefore, that for humans, low leptin levels increase the motivation to exercise and make it easier and more rewarding ” – summarized Stephanie Fulton.
“Mice, human beings and mammals in general is thought that they have evolved to increase the performance of the actual food acquisition behaviors.” In the final analysis, hormones send a clear message to the brain: when food is scarce, it is fun to run to chase something to the end ” – concludes Fault.
