What method is used to calculate an individual's target heart rate?

The method used to calculate an individual's target heart rate involves determining the maximum heart rate and then applying a percentage to establish the target zone for exercise intensity. The correct calculation is derived from the equation that subtracts the individual's age from 220 to find the maximum heart rate, and then that result is multiplied by a desired intensity percentage (often ranging from 50% to 85%, depending on the individual's fitness goals).

In this case, option B correctly encapsulates this process: it states "220 - Age x %HRmax." Here, the subtraction of age from 220 provides the maximum heart rate, and multiplying by the percentage of the maximum heart rate yields the target heart rate for exercise. This method is widely used because it offers a straightforward way for individuals to determine exercise intensity levels that are effective and safe based on their age and fitness goals.

The other options do not represent accurate methods for calculating target heart rate. They either suggest incorrect arithmetic or use an inappropriate formula that does not take into consideration the percentage of maximum heart rate needed to determine an effective target for exercise.