what should a person's target heart rate be for moderate-intensity physical activity?
To calculate a target heart rate for exercise, first determine the maximum heart rate by subtracting the person's age from 220. For instance, a twenty year olds maximum heart rate is 220 minus 20, or 200. The target heart rate for moderate intensity exercise is 50-70% of the maximum. This is calculated by multiplying 200 by 0.50 and by 0.70. This gives you a target heart rate range of 100-140.