Respuesta :
While exercising, if your pulse rate falls below 50% of your target heart rate zone, you should increase the level of intensity.
What is the target heart rate?
The target heart rate is the percentage of your safe heart rate. It can be calculated by subtracting your age by 220. The common target heart rate is 50 to 85%. If the target heart rate falls from 50 then you should increase the exercise.
Thus, the correct option is B.
Learn more about target heart rate
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