AFAA Personal Trainer Certification Practice Exam

Which muscle refers to the muscle that performs the primary movement?

1. Antagonist

2. Fixator

3. Agonist

4. Stabilizer

The correct answer is: Agonist

The muscle that performs the primary movement in a specific exercise is known as the agonist. When engaging in physical activity, the agonist is the muscle that is primarily responsible for generating force and producing movement in the desired direction. For example, during a bicep curl, the biceps brachii functions as the agonist by contracting to lift the weight toward the shoulder. Understanding the role of the agonist is essential for personal trainers, as it helps in designing effective exercise programs that target specific muscles for strength and endurance development. The identification of agonists is vital for tailoring workouts to individual clients' needs and ensuring proper form to avoid injury.