Answer to Question 1
Maximal heart rate is reached at the same time as VO2max is reached. Often, it is necessary to estimate maximal
heart rate when measuring it would be inconvenient or impossible. A good estimate of maximal heart rate can be
achieved by subtracting your age from 220. This estimate has been shown to be within +10 beats of that achieved
during exercise.
Answer to Question 2
Heart rate and stroke volume determine cardiac output. Both increase as exercise intensity increases. Stroke volume
plateaus at about 40 of VO2max but heart rate increases in a linear fashion all the way to VO2max (maximal
exercise)