I teach for the steps.
This is silly, selfish, and not entirely true when I started teaching, but teaching is active; so, now I say I teach for the steps.
I have done the office job and I have been in a classroom. Classrooms create plenty of opportunity to burn calories. Sure, my candy drawer also gets used more, so I am consuming more calories. Nevertheless, a classroom position is an active role.
I walk as I teach. I walk from student to student. I walk from desk to desk. I stand up, I sit down, I stand up, I sit down. I sprint to the bathroom and back. I take kids out to recess. I play at recess. I walk around at recess. I take my students to the cafeteria, to specials, to line-up, to dismissal–and back. I monitor work by walking around the classroom. I monitor testing by walking around the classroom. I go from one meeting to the next, from one classroom to the next, from one end of the school to the other end.
My feet are tired, but by the time I get home I can safely look at my steps app and know I got all my steps for the day. One less thing to worry about–and that is definitely a perk, maybe even a reason, to teach 😉