Reduce the Number of Decisions
Breaks are more than just opportunities to recover. They are crucial for Learning. They allow the brain to process information, move it into Long-term Memory and prepare it for new information.
If we don't give ourselves a break in between work sessions, be it out of eagerness or fear of forgetting what we were doing, it can have a detrimental effect on our efforts. To have a walk or even a nap supports Learning and Thinking.