Among the topics we’re asked about most frequently, Zone 2 training is always near the top of the list. The interest is certainly justified; Zone 2 training is one of the four essential “pillars of exercise” for maintaining health and physical capabilities as we age, as it is arguably the single most important tool we have at our disposal for improving and sustaining the health of our mitochondria, which are central players in cellular aging and metabolic health. With this in mind, we’ve decided to create a one-stop resource to answer common questions and serve as a guide for all things Zone 2: what it is, why it’s important, how to incorporate it into an exercise regimen, and more.