Final answer:
The Rating of Perceived Exertion (RPE) allows a coach to subjectively control an athlete's training intensity and is used to provide a model for progressions in athletic training.
Step-by-step explanation:
The method that allows a coach to subjectively control an athlete's training intensity and provides a model for progressions is the Rating of Perceived Exertion (RPE). The RPE is a scale that measures the intensity of exercise based on how hard an individual feels they are working. This subjective measure is recognized by the Centers for Disease Control (CDC) as a valuable tool because it can account for variables that objective measures, like heart rate monitoring, might not capture, such as the influence of medications. It is particularly useful when creating personalized exercise programs and in managing progressions in athletic training.