Why explain the lack of appetite after training?
Last reviewed: 16.10.2021
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People who are actively involved in sports know that after a grueling training session on exercise machines, one does not particularly want to eat. What is the reason? Does the body have a special mechanism responsible for suppressing appetite after exercise?
Scientists representing the Medical College of Albert Einstein, have thought: probably, to this fact the raised body temperature has to do, as the physical activity contributes to this.
The internal regulation of temperature, as well as the feeling of hunger, is controlled by the hypothalamus - a small department in the brain, which is subject to many physiological processes in the body. For each such process there is a certain group of neurons. The specialists decided to find out: can the same neural group respond to both thermoregulation and food need?
The structures that suppress appetite are located in the zone of the arcuate hypothalamic nucleus. Their functional focus is the analysis of hormonal balance and blood composition (the brain has no direct contact with blood due to the presence of the blood-brain barrier).
In order to recognize the ability of neurons to respond to temperature changes, scientists treated their surface with capsaicin, a pepper alkaloid that affects heat receptors. Most of the neurons felt the action of the alkaloid, which indicated that they have active thermal receptors.
The next stage of the study was laboratory experiments. The rodents were administered a pepper alkaloid directly into the hypothalamus, into the area of the necessary nerve cells. As a result, mice lost their appetite for 12 hours: some rodents ate, but much less than usual. After blocking the thermal neuronal receptors, appetite suppression did not occur with capsaicin.
At the final stage, the rodents spent about 40 minutes on a kind of running track: their temperature increased and was on high figures for an hour. During this time, the mice also showed no marked appetite, in contrast to those animals that did not participate in the "training". It is noteworthy that those mice that had blocked neural thermal receptors, even after training, ate with an appetite.
Thus, the assumption was confirmed: neurons that suppress appetite also react to thermal changes.
I wonder whether researchers will somehow apply the results obtained in practice: for example, in the matter of reducing excess weight and treating obesity. Although, the answer is obvious for many: you want to curb your appetite - go to the gym, sign up for fitness or just ride a bicycle.
Information about the experiment is available on the PLOS biology pages (http://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.2004399).