In the United States, pre-exercise static stretching seems to have become common practice and routine. However, research suggests that it is time for a paradigm shift--that pre-exercise static stretching be replaced with dynamic warm-up exercises. Research indicates that a dynamic warm-up elevates body temperature, decreases muscle and joint stiffness, activates the nervous system, and prepares motor units for contraction. In addition to preparing the body for subsequent activity, a vigorous dynamic warm-up routine can also have a positive effect on several components of fitness, such as cardiorespiratory endurance, muscular strength, muscular endurance, flexibility, and body composition. These components of fitness are considered to be of high importance in relation to overall health. This article presents an example of a 12-minute dynamic warm-up routine that can be incorporated into the first segment of a 35-minute physical education lesson. In this example routine, the first 10 minutes are dedicated to a general dynamic warm-up and the last two minutes are dedicated to a specific dynamic warm-up. (Contains 15 photos.)