Abstract: The present invention allows users to monitor their workouts using a small, portable device which provides feedback regarding speed of exercise repetition and range of motion, enabling the user to use pneumatic or cable driven workout structures safely, efficiently, and effectively. In a typical embodiment, the present invention allows a user to define pre-set requirements, attach the device to a cable-driven exercise structure, and complete the exercise while using the device to monitor the exercise. The device signals to the user if the user's execution of exercise repetitions falls outside the user's pre-set requirements for speed and range of motion. The results of the user's exercise repetitions are displayed on a display screen and are stored in the device's memory, and may then be uploaded onto the user's personal computer to further monitor progress.