A lot of times we describe exercise as being high intensity or low intensity. Sometimes we call it moderate, easy or difficult. These common terms are very nebulous and do not actually tell us much about what is actually going on in the body. In the video below, Dr. Gifford will introduce you to the 4 exercise intensity domains (moderate, heavy, severe and extreme) which are separated because these intensities elicit very different physiology. You will be introduced to thresholds like the lactate threshold, critical power and VO2max which separate these intensity domains.