According to ‘The Power of Habit’, “for many people, exercise is a keystone habit that triggers widespread change“.

“When people start habitually exercising, even as infrequently as once a week, they start changing other, unrelated patterns in their lives, often unknowingly. 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“.

Charles Duhigg

In 2006, two Australian researchers—Megan Oaten and Ken Cheng— enrolled two dozen people between the ages of eighteen and fifty in a physical exercise program and, over two months, put them through an increasing number of weight lifting, resistance training, and aerobic routines.  Week after week, people forced themselves to exercise more frequently, using more and more willpower each time they hit the gym. After two months, the researchers scrutinized the rest of the participants’ lives to see if increased willpower at the gym resulted in greater willpower at home. Before the experiment began, most of the subjects were self-professed couch potatoes. Now, of course, they were in better physical shape. But they were also healthier in other parts of their lives, as well. The more time they spent at the gym, the fewer cigarettes they smoked and the less alcohol, caffeine, and junk food they consumed. They were spending more hours on homework and fewer watching TV. They were less depressed. 

Charles Duhigg