What is the quantitative effect on a person's heart rate as time elapses after exercise?

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megamind-616 eNotes educator| Certified Educator

As a person exercises, heart rate increases. During exercise, the rate of cellular respiration within the mitochondria of muscle cells increases. Cellular respiration is the process that converts glucose and oxygen into carbon dioxide and water. Red blood cells carry oxygen and glucose to cells throughout the body via arteries. The faster a person’s heart beats, the faster such nutrients can be delivered throughout the body. A person’s heart rate increases during exercise in order deliver and restore the food (glucose) and oxygen that is depleted within the muscle cells. Once a person stops exercising, the metabolic rate within the person’s cells slows down. Therefore, one would calculate less beats from the heart per minute as time elapsed after exercise. Such data can be represented graphically. Recovery time is defined as the amount of time that it takes a pulse to return to resting heart rate after exercise. The more fit a person is, the shorter his/her recovery time.

bandmanjoe eNotes educator| Certified Educator

Immediately following exercise, the heart is beating the at the fastest rate it will pump for that physical activity.  If one were graphing the number of heartbeats per minute, it would represent the starting point on the graph.  As time progresses, minute, by minute, the heart will slow in the number of beats per minute.  Each one of these could be plotted on a graph.  This time is known as the recovery time for the heart.  The recovery rate is an indication of the level of fitness for the person doing the exercise.  Athletes tend to recover much faster than nonathletes, primarily because they have conditioned their bodies to such strenuous physical demands.  Ultimately, after 15 to 20 minutes have elapsed, the heart will have returned to what is called it's resting heart rate, which would represent the bottom numbers on the graph.  A quantitative graph of this data should correctly show an indirect relationship between the number of heartbeats per minute and the time elapsed after exercise.