Why is the PAI different for different people after the same exercise?

PAI (Personal Activity Intelligence) is a revolutionary indicator of personal activity that makes heart rate data more meaningful. Converting heart rate values into more meaningful PAI value allows you to know your body condition mode intuitively. Earn PAI by doing any activity that gets your heart pumping. PAI personalizes the difficulty levels for you to reach 100 PAI by using your athletic ability and physical data.
It is normal for different people having different PAI after the same exercise. Your PAI score is based on your age, gender, resting heart rate, and your past 7 days of heart rate data. It’s personalized for you.