In this reflective opinion piece, we introduce the concepts of exercise diversity and physical activity diversity. Similar to dietary diversity and dietary variety, exercise/physical activity diversity represents part of a comprehensive target of ideal health, an objective parameter to audit one's progress towards such a goal, and a means of accomplishing this aim. We defi ne this concept as the number of types of exercise, the number of limbs and body parts exercised or muscle groups involved, the variety of intensity, or the number of variations in methods of exercise used. A non-weighted score may be allocated to each exercise, limb, and muscle group to get a raw idea of diversity.