Which of the following exercises is an example of a multi-joint exercise?

The bench press is an example of a multi-joint exercise because it engages multiple joints and muscle groups during its execution. Specifically, when performing the bench press, the shoulder joints and the elbow joints are involved. As you lower the barbell towards your chest and then push it back up, the primary muscles worked include the pectorals, deltoids, and triceps. This combination of joints working together classifies the bench press as a compound movement, which is beneficial for building strength and muscle mass across several areas of the upper body.

In contrast, the other options primarily focus on isolated movements. The triceps kickback primarily targets the triceps muscle with minimal engagement of other muscle groups or joints, making it a single-joint exercise. The calf raise focuses solely on the ankle joint and works primarily the calf muscles, also fitting the definition of isolation. The leg extension targets the quadriceps while primarily functioning at the knee joint, again making it an isolated movement. This distinction in exercise type illustrates why the bench press is the correct choice as a multi-joint exercise.