Congrats and great job, Alan!
Just got back from the most encouraging inclined treadmill walk yet:
Walk Profile | Incline treadmill one hour at mostly 3.6/15% | Times and Records | Strava
It's not showing on the site, but my phone is showing a Suffer Score of 185. I've only gotten a SS higher than that on a run of around an hour once--way back in May when I weighed 45 more pounds than I do now and did my first sub-one-hour 10K, it was 196.
Average heart rate of 162 today. I could only find one other run with a heart rate that high: my 10K PR run on 8/20:
Run Profile | 10K Self-Race For Training Pace Recalc | Times and Records | Strava
So basically I'm inclined (heh) to treat today's cardio like a very hard run and do a "recovery walk" tomorrow, keeping the heart rate around 140-145, then do another "hard walk" on Thursday. Boredom probably won't allow me to do a 2-hour long walk this weekend, but I might try finding a movie I want to watch on Netflix and giving it a go.
All in all, I'm very encouraged about what is seeming to be the inevitability of losing very little aerobic fitness during my no-running time.
And y'all can start yelling at me now, but the wife even agrees with me that with the way these treadmill walks have gone, the 10/20 Myrtle Beach HM is back on the table as a possibility. If I am cleared to run at my 9/24 Dr. appointment, I'm thinking that I'll do easy runs that rest of that week, and if they go well, do a typical-for-me 5-run week the week of 9/30, then a 2-week taper down to race day.