I have a potentially dumb question about heart rate monitors. Is there one out there that tells you how many calories you've burned? I was reading about the FitBit but it seems like you have to log onto the internet and estimate the calories burned yourself. Is that accurate? I would rather have one that knows my age, height, weight etc and tells me how many calories i've actually burned. I do P90X and 10 minute trainer and i've seen the estimates for calories burned online but I know that everyone is different. Does this device exist? Or am I looking too far into the future and it hasn't been invented yet? Thanks in advance!