First and foremost, physical fitness is a vital component of health that is often overlooked or even dismissed by some nutrition gurus. Its importance must be considered, and indeed, health seekers would do well to establish some sort of a sport or exercise program in their lives. For most of our evolutionary history, we humans roamed from place to place hunting as nomads. The activity level required for survival in such an environment was quite high on a fairly consistent basis. Walking miles a day, hunting, foraging, building shelter and other practices require large amounts of energy expenditure all while strengthening the heart, lungs, muscles and more.