When I asked my doctor about the heart monitors at the gym after a couple months of working out and my heart rate staying at the "too high" level, she told me that because of my size now compared to my size before weight gain was so big that my heart rate would continue to be extremely high during any exercise until I had lost a significant amount of weight. She also said that my workout should be for my overall well-being not just weight loss, and it was not good to try and monitor how many calories I am burning in a workout because it would be a temptation to splurge if it started feeling like I was doing good and a discouragement if the calories didn't feel like they were worth the exertion. Anyway, at that I decided to not pay attention to the gym's monitors anymore and never even considered buying one. I wonder if other's who have a lot of pounds to lose have gotten similar advise from their doctors concerning heart monitors.
And it's interesting to me that this thread started with "abetterme' being discouraged by calories lost not seaming equal to the exertion. I tried entering my workouts and heart rate into some workout app on my phone and it basically figured I only burn 450-500 calories during a 65 minute workout on the elliptical that is hard for me, (like keeping my asthma inhaler on me and going through two 24 ounce bottles of water, dripping sweat.) That is discouraging to me, so I'm inclined to take my doctors advise and steer away from monitoring my heart rate until I am closer to just obese instead of morbidly obese and now I am scared to ever start monitoring how many calories I am burning.