Maximum heart rate is the maximum heart rate (the number of times your heart beats per minute (bpm)) that an individual can attain that is based on his/her genetics. The most common calculation for the maximum heart rate is: 220-Age
In Paul's case, Age=17, so his maximum heart rate is 220-17=203 bpm.
Even though Alexandra could talk with her friends during dance class, she couldn't sing along to the songs. Moderate best describes her heart rate during this activity.
