LaFlore, you did read that right. A HRM can be used to keep you from overtaxing the heart. Lets say you set off the upper limit alarm, maybe you can alter your pedal cadence from a low cadence hard push to a higher cadence spin to bring your heart rate down while keeping the same speed (or vice versa). It is very possible to overtax the heart before you feel 'the burn' from lactic acid builup in your legs. For some people all it takes is walking up a flight of stairs and I can gaurantee you they didnt fell 'the burn'.

Is this something only people with pre-existing heart need worry about? To be honest with you, I dont know. Think of a HRM as a tool that has several functions. Choose the function that best serves you purpose. Maybe you should try it in a crit.....perhaps your HR isnt getting high enough!?!?!?