Cardio May Be a Waste of Time Without This Knowledge
The most important factor for improving cardiorespiratory fitness (cardio or CR) is the intensity of the workout. Changes in CR fitness are directly related to how “hard” an aerobic exercise is performed. The more energy expended per unit of time, the greater the intensity of the exercise, the greater the effect on cardiorespiratory fitness.
You have to know how hard is “hard” to determine if an aerobic exercise like running is producing a CR training effect or if it’s just burning a few calories. The heart rate during work or exercise is an excellent indicator of how much effort you are exerting. Only by keeping track of your heart rate during a workout can you be sure that the intensity is enough to improve your CR fitness level. In other words, your ability to monitor your heart rate is the single most important key to success in CR training.
Training Heart Rate (THR) = Desired Intensity of the Workout
THR is the heart rate at which you need to exercise to get a training effect. The U.S. Army fitness gurus have given us two methods to determine THR. The first...