It's a logarithmic curve. On a 1 to 10 scale, increasing activity from 0 to 1 provides a large decrease in mortality. Going from 1 to 2 another big jump. But

It's a logarithmic curve. On a 1 to 10 scale, increasing activity from 0 to 1 provides a large decrease in mortality. Going from 1 to 2 another big jump. But 2 to 3 is less, until finally it plateaus. But yes, people don't realize that even just walking at a moderate pace for 20 min 3 times a week provides huge benefits if you are otherwise completely sedentary.