Edgelow recommends a 20 minute walk 3-4 times a day.
I was doing this for a couple weeks now and it seems I can (barely) handle it.

He prescribes an aerobic walk starting with the pulse rate of 65% which is about 115 for my age. I was a runner before these problems started and I need to run, not walk, to get my pulse this high. Even if I walk very fast, it stays under 100.
I tried warming up by running a short distance to get my pulse to 115, but then I am not getting enough air using abdominal breathing (without engaging the scalenes).
Maybe this simply means years of running made my heart more efficient than average...

Did anyone have success with aerobic walking?