This study focuses on acute changes in gastrocnemius muscle stiffness. The main objective was to investigate exercise-induced changes in muscle stiffness. Healthy adult subjects were included in the research. Three different calf-raise exercise protocols were used within the study. The first protocol involved 30 seconds of work and 30 seconds of rest. The second protocol consisted of 15 seconds of work and 45 seconds of rest. The third protocol utilized 45 seconds of work and 15 seconds of rest. The study was sponsored by Princess Nourah Bint Abdulrahman University and has been successfully completed.