Welcome Christine. I don't know a lot about heart rates and pulses, but I think that walking is the best exercise there is. What could be more natural and expected of the human species? If you can walk at all, I suggest taking it slowly. Enjoy it. Don't try to do too much, but do a little everyday.
Also, start tracking your food. You will soon know what to avoid. Make sure you get the calories, protein and carbs you need. Try not to go over.
You're never too old to do goofy stuff.
-Ward Cleaver ("Leave It to Beaver")
| current weight: 130.8