Training programs should force students to repeat skills at regular intervals because habits not reinforced are weakened through?

The principle behind the correct choice is grounded in the idea that skills, once learned, require ongoing practice to maintain proficiency. When a skill is not practiced regularly, the neural pathways associated with that skill can weaken over time, leading to diminished ability and performance. This concept is particularly relevant in physical training and skill-based learning, where muscle memory and cognitive recall play essential roles.

In the context of training programs, emphasizing the need for repetition ensures that students solidify their skills through consistent practice. This repetition reinforces neural connections, creating stronger habits and ensuring that students retain what they have learned. Without this reinforcement, skills can fade or deteriorate, impacting a student's overall competence and confidence.

In this case, other concepts such as readiness, exercise, and association, while they may relate to learning and performance in various ways, do not specifically address the phenomenon of skill decay due to lack of practice as effectively as disuse does. Disuse highlights the importance of continuous engagement with a skill to prevent slippage in performance, which is why it is the correct answer in this context.