An exercise machine that varies a resistive load based on sensed changes in intensity of exercise. In one example, an electronic control system of a stationary bicycle adjusts a flywheel resistive load based on changes in the user's pedal cadence. During the exercise routine, subsequent increases or decreases in the pedal cadence cause, respectively, increases or decreases in the flywheel resistive load. In addition, the control system may execute the exercise routine after actuation of a single input key. In another embodiment, the user may simply start to exercise. The electronic control system may calculate a default flywheel resistive load based on initialization parameters, such as demographic data and/or exercise preferences.