Don't Mow, Jog-Mow!
I don't know why this never occurred to me before, but jogging behind the mower today lopped about fifteen minutes off my total mowing time. I didn't jog continuously but rather in 3-5 minute stretches. And I didn't stop because I was tired as much as my mind wandered and I'd regress to walking.
I may make this my weekly aerobic workout as there is an emerging backlash against HIIT and a modest movement towards old-school aerobic stuff. I get a little bit of anaerobic work and a lot of light aerobic work, but nothing in the middle ... until now.