-- If the person to whom you're explaining them is alongside you, then
you should adjust your walkiing rate to match his, so that he remains
within earshot for the duration, and receives the benefit of the complete
explanation.
-- If you're presenting the explanation on the phone, then your walking
rate doesn't matter. But you still must adjust it to avoid running out of
breath as you speak, and you must also maintain your own awareness
of your surroundings, so that your explanation is not inadvertently
truncated.
