An exercise apparatus has an exercise station that is selectively moved by a user and has first and second weight stacks that provide selected resistance to movement of the exercise station. Based on the relationship, a post-ventricular atrial refractory period is defined. The cable includes a first sheath that covers a conductor and is made of a first resin material, and a second sheath that covers the first sheath. The script GUI module receives information from the executing script and determines if the information comprises an input type command.