Prove that physical activity has a beneficial effect on the human body as a whole.

It has been proven that systematic training makes muscles much stronger, and the body as a whole becomes more adapted to environmental conditions.
During physical activity, the body produces special substances that are very similar in structure to serotonin (it is the hormone of happiness). This has a beneficial effect on a person’s mood. A number of other substances are also produced that allow cells (including nervous ones) to become even more resilient. Based on this, we can conclude that physical activity really positively affects both physical fitness and mental abilities.