Visit this page to determine your Maximum Heart Rate (MHR). Scroll down to “Calculator.” Enter your age, choose “Running” for the sport, and “Average” for the Experience level. Use the value given at the top line, the “Combined Londeree, Moeschberger and Miller” method. This is your MHR. For Steady State workouts (see below), you should be training at between 65-75% of your Maximum Heart Rate (MHR).