Properly setting the circadian rhythm leads to a regular body temperature rhythm that influences metabolism and exercise willingness.

“So one of the most powerful things about setting your circadian rhythm properly is that your temperature will start to fall into a regular rhythm. And that temperature has a very strong effect on things like metabolism and when you will feel most willing and interested in exercising, typically the willingness to exercise and engage in any kind of activity mental or physical is going to be when that rise in temperature is steepest. When the slope of that line is greatest.”