Exercise increases your overall health and your sense of well-being, which puts more pep in your step every day. But exercise also has some direct stress-busting benefits. It pumps up your endorphins. Physical activity may help bump up the production of your brain's feel-good neurotransmitters, called endorphins.
Humanity? Hope this helps
If a system fails then the person would undergo diseases
Because it can catch another germ or virus