For example, if you want to work at an endurance or aerobic training level, you would likely work at 65 to 75 percent of your maximal heart rate. Once you've determined your target heart rate, strap on the monitor and get to work. If you notice your heart rate is too high, take it easy. Turn up the intensity. You might be surprised to find that you weren't working as hard as you always thought.
Most runners adhere to their training schedule with a religious fervor.