Zone two cardio has received a lot of attention lately. Doctors and researchers tout the benefits associated with mitochondrial efficiency and longevity. But zone two cardio is time-consuming and may be difficult to realistically keep up with. At the same time, others are claiming that women naturally have a better ability to use fat as fuel and a higher composition of type 1 muscle fibers, so zone two cardio is unnecessary. Where is the "truth?" What SHOULD we be doing for our health and longevity? Dr. Shannon breaks it down in this episode.