Yes, I am making progress towards this goal. I’m in $city for the next 6 weeks, and am (ab)using the treadmill daily or every other day.
When I started, a 3 mph walk and 0% incline (i.e. walking downhill) was enough to put me above the cardiac exercise zone (>80% suggested maximum heartrate). Now I’m able to run (4.5mph) in spurts (10%), walking the rest (90%) without exceeding my cardiac capacity. The annoying thing is that my outside calf muscle fatigues much sooner than the rest of my legs. I’m going to have a go with my new boots instead of ancient-and-half-biodegraded-tennies and see if that helps.
Goal for next week: 20% running, 80% walking, 0% dying.