Not all steps are created equal. When you’re walking, your heart is typically not working very hard, so you’re contributing much to your cardiorespiratory fitness.
PAI focuses on the one thing that matters most to your overall health and longevity - your heart. PAI urges you to do activities that elevate your heart rate. A short run can contribute more to your overall health than an hour-long walk. In fact, a high step count alone may not be optimizing your protection from cardiovascular disease.
PAI was derived from one of the world’s largest health studies. It showed that consistently maintaining 100 PAI reduced the risk of cardiovascular disease mortality by up to 25% and increased life expectancy by up to 5 years. Decades of research has proven that cardiorespiratory fitness is one of the leading predictors of health and longevity. For most people, walking will not elevate the heart rate and does not improve cardiorespiratory fitness.
Also, steps are different for different people. Fitter people have to do different activities to get their heart rate up; a high step count alone may do very little to maintain or improve a fit person’s heart.
Lastly, not all activity includes steps. You should get credit for anything that gets your heart pumping. This is another reason why PAI is a more accurate measure of health than step counting - because it counts even those activities that don't involve steps like biking, swimming, rowing, dancing and even working in the garden.
Below is some actual user data showing that many people can reduce their risk of CVD mortality without reaching 10,000 steps.