AP BIOLOGY

Detailed explanation-1: -When you exercise, your heart beats faster to meet the demand for more blood and oxygen by the muscles of the body. The more intense the activity, the faster your heart will beat. Therefore, monitoring your heart rate during exercise can be an excellent way to monitor exercise intensity.

Detailed explanation-2: -They measure their pulse immediately after their exercise, then at 1 minute intervals, until it returns to normal resting heart rate. They plot this on a graph and explain what they can see from the graph. They could then investigate how long their heart takes to recover from different types of exercise.

Detailed explanation-3: -Both the HRR method and the percent of 220-age equation are commonly used for the determination of aerobic exercise intensity in healthy and clinical populations due to their practicality and ease of use.