Mihaly Csikszentmihalyi describes how some surgeons go on “automatic pilot” the morning before surgery. They eat the same breakfast, put on the same clothes, drive to the hospital via the same route.
Habits like those of a morning routine are mostly unconscious. Your body knows how to go through the motions, especially in the morning when your mind is still slowly waking up.
This applies to habits throughout the day as well: eating your meals at the same time (even eating the same foods); following a strict schedule, especially for mundane tasks like responding to email, adding events to the calendar, sending progress reports to your manager, etc.
Similar to how a weightlifter moves slowly and sparingly in between sets as he puts away equipment and changes weight on the machines, so that when he actually gets under the weight of the bar, his muscles are primed and rested to push the limits of his maximum strength.
Routine habits allow you to perform necessary tasks consistently while also freeing the rest of your mental energy to focus on the part of your job that actually requires your creativity, innovation, and dynamic skill.
Source: Mihaly Csikszentmihalyi, Flow, pg. 157.