Computrainer controls the resistance and regulates the power level for each rider via the trainer to emulate the climbs/descents of actual rides as shown on the TV. There's also a video game type activity where you see avatar riders on the screen and resistance is controlled by the CG terrain and by how close you're drafting. These are the attractions of using Computrainers and group Computrainer sessions. Simply displaying what individuals are doing on there separate bikes and trainers is a lot less interesting.