During physical activity of high-intensity your heart will be at a percentage of its maximum rate which range shows the correct percentages during this type of activity

70% to 85%

Explanation:

During exercise, our heart tends to beat faster so that more oxygen could be supplied to the cells. The level of the intensity of the physical activity interprets how faster the heart shall work to meet up the supply.

The American Heart Association suggests that the heart rate shall increase by 50% to about 70% for moderate type physical activities. The American Heart Association also suggests that the heart rate shall increase by 70% to about 85% of the normal heart rate for high intensity exercises.

the more fit you are, the faster the recovery. your heart rate drops most sharply in the first minute after you stop exercising; it should then fall about 20 beats a minute—a drop of less than 12 beats a minute is considered abnormal. this “recovery heart rate” is measured as part of an exercise stress test.