As an out of shape senior citizen I had to be careful about pushing my heart rate too high. Strenuous exercise would easily kick it over 200 beats a minute. I bought a wrist type monitor, then treadmill with pulse handgrips and in both cases my rate would be all over the scale.I finally decided to try one with a chest band. I bought one for my wife and myself and we have been using them for about a month. This does everything I have wanted...Accurately monitor my heart rate.