Bill, you're truly an inspiration to all of us here in The Waiting Room, looking ahead to our future surgeries. I, like several others, look to an unknown time for mine, and continue to push as hard as I always have -- lest I lose "the edge" too early. I run and work out 5 days a week, and I use a similar chest strap/wrist "watch" heart rate monitor. My resting heart rate runs from the low-low 50's to low 60's (some mornings down in the high 40's), probably due to 25+ years of running. I don't run fast (about 9 min/mile) but plenty fast for my age (56), and on the treadmill my heart rate will gradually elevate up to the high 150's or even low 160's by the time I hit 4 or 5 miles. My cardio says "As long as it feels OK, don't worry -- you won't break it." My heart rate goes down a good 30 clicks within a minute, so that looks good, too. I just keep doing all this for two reasons: 1) Because it helps me to feel good. 2) So I can be acutely aware if my exercise tolerance begins to slip for more than a day or so.
I would venture to guess that you should keep a journal of your exercise for a third reason -- to track that wonderful progress you're making, and to be able to continue to encourage the rest of us who look forward to climbing the mountain.
Thanks for sharing.