Took a very easy paced bike ride after work, for the first time ever I was able, for some of it, keep the heart rate down in zone 1, the rest of it was down on the low end of zone 2. So that's a good sign that my cardio system is improving. I found it very pleasant to ride like that, just look around at the scenery and think some about things.
It's probably a good idea for me to try do good chunks of time down in zones 1 and 2. My fitness and health was so wiped out, I'm starting from zero.