• Typically, people who exercise start eating better and becoming more productive at work. They smoke less and show more patience with colleagues and family. They use their credit cards less frequently and say they feel less stressed. It's not completely clear why. But for many people, exercise is a keystone habit that triggers widespread change.

    "The Power of Habit: Why We Do What We Do, and How to Change". Book by Charles Duhigg, April 5, 2012.