Final answer:
The resistance training method where weights are increased or decreased across sets is known as pyramiding. It is designed to increase muscle strength and mass by adjusting the exercise intensity across the workout.
Step-by-step explanation:
The resistance training method described by a light to heavy or heavy to light progression of sets is known as pyramiding. In this method, the weight either increases with each set (light to heavy) or decreases (heavy to light), while the number of repetitions typically moves in the opposite direction (high to low or low to high). This progression allows the muscles to adapt and grow stronger as the weight increases, or to experience a different kind of strong>muscle endurance and strength as the load lightens over the workout session.
For example, a powerlifter might begin with a lower weight (light) that they can lift for many repetitions and increase the weight (heavy) with each set, reducing the number of repetitions as they progress. This ensures that the intensity of the exercise continually increases—a principle that's essential for effective strength training to produce ever-greater results and increase muscle mass.