ACSM Personal Trainer Certification Practice Exam 2026 – All-in-One Study Resource to Achieve Certification Success!

Skeletal muscle is the type of muscle tissue that is characterized as voluntary and is composed of striated fibers. This means that the contraction of skeletal muscle is consciously controlled by the nervous system, allowing individuals to perform movements such as walking, lifting, and exercising. The striated appearance of skeletal muscle is due to the organized arrangement of myofibrils, which contain the protein filaments actin and myosin.

In contrast, cardiac muscle, while it is also striated, operates involuntarily and is mainly found in the heart. Smooth muscle, which lacks striations, is also involuntary and is found in various organs, such as the intestines and blood vessels. "Connective muscle" is not a recognized type of muscle tissue in human anatomy and does not pertain to muscle characteristics. Thus, skeletal muscle stands out distinctly among these options for its voluntary control and striated structure.