What is endurance exercise?

The essence of endurance exercise is to go farther – to keep doing an exercise long enough so that the body must find more efficient ways of moving, of processing energy, sending blood, etc. For untrained muscles, a walk of 10 minutes will do this. As we push back this threshold, our first goal is to get to 3 sessions a walk of 30 minutes each. For continuing progress, one of these could be a long one that pushes up to the current endurance limit or beyond (45 minutes, then 60 minutes, then whatever you want).