To improve a specific muscle performance element, the resistance program should match the constructs of that element.

• A. Overload principle
• B. Reversibility principle
• C. Specific adaptations to imposed demands principle
• D. SAID principle

Answer: (C)

Adaptations are specific to the demands placed on the body. To improve a particular muscle performance element, the resistance program should mirror the constructs that define that element—such as contraction velocity, force level, duration, and movement pattern. This is the SAID principle: training adaptations occur in the same form as the imposed demands, so designing the program to match those specific characteristics yields targeted improvements. For example, building maximal strength calls for heavy loads with lower reps to maximize force, while improving power or speed requires moving with higher velocity and appropriate loading, and endurance targets longer efforts with higher reps. Other principles like overload or reversibility are important for progression and maintenance but don’t capture the targeted specificity of adaptations as clearly.