Because Not Doing It leads to trouble.
One gets busy. One gets stressed. One rolls out of bed and starts working at, say, 6:00 or 7:00 a.m.
One skips the exercise program one so carefully devised (more on this in a future blog).
One sleeps poorly.
One eats poorly.
One does this for several weeks.
One day finally one looks at oneself in the mirror. In horror.
Bloated, exhausted, Cortisol pumping like a fire hose, one decides it would be a good day to go for a run.
And everything gets better. Much, much, better.
Just Do It.