The most important factor in improving cardiorespiratory fitness (cardio or CR) is training intensity. Changes in CR fitness are directly related to how “hard” an aerobic exercise is performed. The greater the energy expended per unit of time, the greater the intensity of the exercise, the greater the effect on cardiorespiratory fitness. You need to know how “difficult” it is to determine whether an aerobic exercise such as running is producing a CR training effect or whether it is just burning a few calories. Your heart rate during work or exercise is an excellent indicator of the effort you are exerting. Only by monitoring your heart rate during a workout can you be sure that the intensity is sufficient to improve your CR fitness level. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an Original Essay In other words, your ability to monitor your heart rate is the most important key to success in CR training. Training Heart Rate (THR) = The desired training intensityTHR is the heart rate at which you need to exercise to achieve a training effect. The US Army fitness gurus have given us two methods for determining THR. The first method, percentage of maximum heart rate (%MHR), is easier to use, while the second method, percentage of heart rate reserve (%HRR) is more accurate. %MHR method. With this method, THR is calculated using your estimated maximum heart rate. You can estimate your maximum heart rate (MHR) by subtracting your age from 220. Therefore, a 20-year-old would have an estimated maximum heart rate (MHR) of 200 beats per minute (220 - 20 = 200). in poor conditions he should practice at 70% of his MHR; if in relatively good shape, at 80% MHR; and, if in excellent shape, 90% of MHR. Examples: A 20-year-old in good physical condition would have a THR of 160 beats per minute (BPM). 220 - 20 = 200 *.80 = 160 BPM. A thirty-year-old in good physical condition would have a THR of 152 beats per minute (BPM). 220 - 30 = 190 *.80 = 152 BPM. A 40 year old in poor physical condition would have a THR of 126 beats per minute (BPM). 220 - 40 = 180 *.70 = 126 BPM. %HRR Method A more accurate way to calculate THR is the %HRR method. The range between 60 and 90% HRR is the THR range in which people should exercise to improve their CR fitness levels. If you know your overall CR fitness level, you can determine what percentage of HRR is a good starting point for you. For example, a person in excellent physical condition might start with 85% of their HRR; if it is in reasonably good condition, 70% HRR; and, if it is in bad shape, to 60% HRR. Most CR workouts should be conducted with a heart rate between 70 and 75% HRR to achieve or maintain an adequate level of fitness. A person who has achieved a high level of fitness may benefit more from working with a higher percentage of HRR, particularly if he or she cannot find more than 20 minutes for CR exercise. Training with an HRR below 60 does not harm your heart. , muscles and lungs an adequate training stimulus. Exercising above 90% can be dangerous. Before starting aerobic training, you need to know your THR (the heart rate at which you need to exercise to achieve the training effect). The following example shows how to calculate THR using resting heart rate (RHR) and age to estimate heart rate reserve (HRR). The example is a physically fit 20-year-old).