Because your legs are working at a faster pace than they would if it was a slow walk.
because we walk a long way there and back
Yes. If you have dry, yellowish brown grass you tend to walk slowly. This is because you are probably depressed if your grass is dead.
Because sometimes you walk fast and sometimes you walk slowly.
Yes, "walk slowly" is a fragment because it does not contain a subject and a verb to form a complete sentence. It lacks the necessary elements to express a complete thought.
To walk or march with labor; to jog along; to move wearily.
You can say WALK SLOWLY. Commanding voice is needed to show it in that context.
because there is usually a butt load of stuff they have to haul as well as people on them
walk around
Because when you walk around the mall you might get tired going all the way across it looking for stores.
The walk trail in this area features scenic views, varying terrain, and moderate difficulty level.
because they dont have a lot of energy and contain more fats which is exactly what you dont need