It usually takes 5 minutes to return to a quiet heart rate (the heart rate drops very quickly after just stopping exercise). )
The pulse frequency of 6 seconds immediately after exercise was measured as the exercise heart rate, and the pulse frequency of 6 seconds was measured again at 1 min after exercise as the recovery heart rate.
Heart recovery rate = (exercise heart rate-recovery heart rate)/10
The higher the value calculated according to this formula, the faster and healthier the heart will recover.