I never proselytize running. However, when an acquaintance expressed curiosity about my running and an interest in starting, I thought to create this set of references for her. Our brain makes up 2% or less of our body by weight, yet we spend so much time pursuing careers, distracting it with idle entertainment, educating it, or just polluting it. At the same time, we neglect our body by not making it move or poisoning it with foods laced with sugar, fat, salt, or alcohol. As a result, life expectancy in the U.S. is declining, and prescription drug-managed morbidity is increasing. As a result, the typical U.S. female will spend half her lifetime health care expenditures after age 65.
Dopamine is evolution’s reward system for behaviors that increased the reproductive success of hunter-gatherers, long-distance hunting and gathering, eating high calories foods, and sex. Today we no longer persistence hunt, but regular exercisers enjoy the rewards of the long hunt.