I worked for NASA back in the day and one of the astronauts—I can’t remember who—said to an inquiring reporter who asked him about exercise that “every human had a finite number of heart beats and he wasn’t going to waste any of his with exercise.”
That was Neil Armstrong
Well, it convinced him when he heard it. :-)
Exercise makes me feel better but I’m not an athlete so it’s never overdone. Getting my heartrate up some clears the brain fog, helps my mood, helps me sleep, and lowers my BP and cholesterol. I’m probably in the middle ground zone.