"We have not spent the last 65 million or so years finely honing our physiology to watch Oprah. Like it or not, we are the product of a very long process of adaptation to a harsh physical existence, and the past couple centuries of comparative ease and plenty are not enough time to change our genome. We humans are at our best when our existence mirrors, or at least simulates, the one we are still genetically adapted to live. And that is the purpose of exercise.”
Rippetoe, Mark (November 2007). “Be Alive. Be Very Alive.”. The CrossFit Journal 63: 17.