Answer:
twelve
Step-by-step explanation:
People would aim their Target Heart Rate for at least 15 - 20 minutes [¼ - ⅓ hour] workout time, and ideally 35 - 45 minutes [7\12 - ¾ hour]. If someone is a beginner, they would normally start from 65% - 70% of his\her maximum heart rate and gradually increase the intensity.