Where does your data come from?

Several people are going to buy heart rate monitors, so I thought I'd give my experience with the data.
I like the data from the Garmin more than the Polar. It shows the minute by minute heart rate, which is really cool. However, Garmin does not calculate calories from the heart rate data. It uses a combination of distance and weight. So you don't get a calorie count from doing indoor cardio. That stinks. The Polar uses your age, weight, height, and max HR to determine calories. Polar offers a GPS module for the watch I have. I'll have to research whether Polar offers the same minute by minute data for the HR if it has the GPS attached.
Some of the other data you may be interested in is your VO2 Max and Max HR. These are interesting numbers, but you have to pay to get them. I have done it at LifeTime Fitness and Duke Sports Medicine. Duke costs more, but gives you more data. I'm not sure the extra data, like lactate tolerance, is really useful unless you exercise for a long time, like running and cycling.
You can see my data from Duke in my Public folder on the J drive in the "Duke Data" folder.