You know how your Doctor is always saying "lose weight, get more exercise and you'll feel better" ? I knew mine was at least partially right, but grading the exercise was a real pitfall. He couldn't teach me how to tell when I am exercising too hard or too little. I wouldn't feel the effects until hours after, sometimes days. And my limits seemed to change randomly. I was making myself worse by overdoing things, then making myself worse by being afraid of overdoing again and doing too little.

So, the solution for me has been the use of a heart monitor -- one of those strap things that goes into your bra and transmits to a wrist receiver. It measures my reaction to my exercise warm-up and then sets an appropriate limit for that particular time. It beeps to nudge me to slow down before I can feel the fatigue, and beeps to me to speed up when I am taking it too easy. I am becoming more fit without flaring, and I also use it to keep within my limits when I am doing housework. Best of all, unlike my well-meaning husband and friends, it doesn't get offended when the beeps nag me and I yell at it!

Hope this helps some of you.

Unfortunately with me me that would be a problem. I have high blood pressure and am on medication (Toprol) to control it. So unfortunately also controls heart rate very well. It is a real bummer at the gym, when I test my heart rate on those pad thingies and eventhough I am working pretty hard, my heart rate doesn't rise very much...only a point or two at the most.
I hope it works for others though! Its a good idea!