Monitoring heart rate while training is a useful tool for determining the intensity of a specific exercise session. Heart rate, or, more importantly, percentage of maximum heart rate, is used to determine what bodily systems are being trained and improved during a particular exercise. Monitoring heart rate while training is the easiest and most reliable way to measure an athlete's intensity level during training outside of a laboratory.
Heart rate monitoring is employed by many different types of athlete's, from long-distance runners and cyclists to swimmers and skiers. Any exercise that lasts longer than two minutes is considered aerobic. Aerobic exercise differs from anaerobic exercise in that the the muscles are using oxygen, whereas muscles run off of stored glycogen during anaerobic exercise. This means that, if the exercise being performed lasts more than a couple of minutes, the muscles require oxygen provided by the heart to continue functioning. The amount of times the heart beats per minute (heart rate), as compared to the athlete's maximum heart rate, is an excellent indication of how hard the athlete is working.
The easiest way to determine your maximum heart rate is by using the following formula: Maximum Heart Rate = 205.8 − (0.685 × age). So a 20-year-old athlete should have a maximum heart rate of approximately 192 beats per minute (BPM). The more complicated and accurate method of determining maximum heart rate is through the use of a cardiac stress test, which involves the use of an electrocardiogram (EKG) machine in a laboratory setting. Monitoring heart rate while training can be most easily and effectively be achieved using a handheld electronic heart rate monitor.
Percentage of maximum heart rate is the measurement used to prescribe exercise intensity. There are three main facets of aerobic performance that an athlete would normally target for improvement, including aerobic endurance, lactate threshold, and maximum volume of oxygen, commonly known as VO2 max. Aerobic endurance represents a low exercise intensity level that is maintained for an extended period of time, and can be improved by maintaining 70-75% of maximum heart rate for the duration of the exercise. An athlete's lactate threshold is the point at which lactate removal is equal to lactate production, and should be performed at 80-90% of maximum heart rate. An athlete's VO2 max is the maximum capacity of an athlete's body to transport and use oxygen during exercise, and only occurs at or near the athlete's maximum heart rate, typically 95-100% max heart rate.
Monitoring heart rate while training is an effective and simple way to measure the intensity of any aerobic activity. When an athlete's maximum heart rate has been determined and the aforementioned heart rate training techniques are employed, the athlete's overall aerobic conditioning will be greatly improved. This is also a great way to determine maximum performance for anyone doing aerobic exercise.