1. An interactive exercise system, comprising: a computer system; an exercise machine having resistance setting means for setting the resistance experienced by a user while exercising, and further having speed sensing means for sensing the speed at which said user exercises; a controller suitable for controllably setting said resistance setting means, and further suitable for collecting speed data from said speed sensing means; video playback means for playing from previously recorded storage media of video data including captured natural video image sequences; wherein said storage media further includes course data; and said computer system operates said video playback means and communicates with said controller and processes said speed data from said exercise machine and said course data from said storage media and calculates and appropriately directs said controller to control said resistance setting means of said exercise machine, thereby providing simulation of varying degrees of difficulty when said user operates said exercise machine, as would be consistent with what would be experienced traveling through a real exercise course.