To improve your cardiovascular fitness you must engage in active aerobic activities or active sports that are of sufficient intensity to get your heart rate into your target heart rate zone. The two most commonly used methods of determining target heart rate zone are the heart rate range (HRR) and the percent of maximal heart rate (% maxHR) methods. The target heart rate zone for the HRR method is 50 to 85%; for the % maxHR method it’s 65 to 90%. The target heart rate zones are different for the two methods because of the way they are calculated. However, for both methods the lower number represents the minimum heart rate necessary for achieving cardiovascular fitness benefits. The following are two calculators for determining your target heart rate zone. For the HRR method you will need to know your age and your resting heart rate. The best way to determine your resting heart rate is to take your heart rate before you get out of bed in the morning. Take your heart rate from your carotid or radial artery (see chapter 1). For the % maxHR method you will only need your age. You should also be able to do these calculations without using a calculator (see chapter 7).