Workout Planning
Heart-rate training requires special attention to planning. Most workouts you will perform with a heart monitor will be a form of interval training, requiring concentrated bursts of effort split up by periods of rest. Different intervals target different areas of overall fitness ranging from cardiovascular endurance to sheer power output. Combining different training models will help you achieve a targeted fitness program that can be modified as your body responds (or doesn't respond) to various workout styles. To facilitate more precise planning, keep a workout journal, noting workout types, times, average, high and low heart rates, and general physical response during efforts.
Precision During Training
Heart rate monitors give you real-time cardio feedback during workouts. This information is essential for precision during interval-driven or hard-intensity training. Most workouts of these types require you to accelerate your efforts to specific heart rate zones for a period of time, then rest until your heart rate returns to a set low threshold. Although rudimentary interval training can be achieved without a monitor (using perceived effort), workouts targeting specific areas of fitness generally require your active knowledge of your heart rate.
Safety
Many people choose to use heart rate monitors for general endurance and strength based workouts for safety. A heart monitor will not only tell you if your workout is pushing your body hard enough, but it will also tell you when you've gotten too intense. Certain levels of aerobic activity can become dangerous if not closely monitored. For anyone attempting very high- intensity training, and any athlete with a cardiovascular condition or other limiting physical factor, a heart-rate monitor is crucial for safety during workouts.