Answer:
60 to 80%
Step-by-step explanation:
For maximum benefit, the heart rates during exercise regimes should be between 60 to 80% of an individual's maximum heart rate.
The maximum heart rate varies from individuals to individuals and largely depends on age. It is calculated by subtracting one's age from 220. For example, a person that is 40 years old would have a maximum heart rate of;
220 - 40 = 180 beats per minute.
Such a person's heart rates during exercises should be between 108 and 144 beats per minute for maximum benefits.