Final answer:
The double progressive strength training protocol requires increasing the weight as muscle adapts, ensuring continual muscle growth. By doing so, it prevents a plateau in strength gains and muscle size.
Step-by-step explanation:
The double progressive strength training protocol involves incrementally increasing the weight lifted during strength training exercises as muscles adapt to specific loads. This approach is predicated on the principle that to achieve continued muscle growth and strength gains, the intensity must be progressively increased. The protocol dictates that once a lifter can perform a certain number of repetitions with a given weight, the load should be increased to continue challenging the muscles. This ensures that the muscles do not become accustomed to a specific weight, which would otherwise lead to a plateau in strength and muscle size gains.
With this training method, specific values signify when to increase the resistance. For example, if an individual can perform a set number of repetitions easily, it may be time to add more weight to continue the growth stimulus. The actual values may vary depending on the program, individual goals, and other training variables, but a common practice is to increase the weight when the athlete can exceed their target repetitions by one or two reps in two consecutive workouts.