I have CFS & hypothryoid. During walking for exercise my heartrate can go very high with little effort and I'm NOT even close to huffing and puffing (something I'd expect with a heartrate this high)... up to and over the 85% sometimes. Just seems weird. Two questions: 1. Is this a recurring/normal thing for people with CFS to have such high heartrate with little effort in exercise? Does anyone else notice this too? 2. Should I respect the heartrate first and foremost and do even LESS... or should I ignore the heartrate monitor and focus more on the feeling/breathing factor? THANKS!!!