MUDGUTS
Getting your heart rate that high during excercise is not good. There is a maximum heart rate called the anaerobic threshold above which you are not doing any good. You should aim to exercise just below your threshold to get maximum benefit (please excuse me if you are a highly trained athlete and 190bpm is within your anaerobic threshold!)
For accurate determination of your anaerobic threshold you need to have blood samples taken after exercising, there is an easier way of estimating it.
I remember that when I trained heavily for the boat club years ago, mine was around the 160-170 mark.