Abstract: An exercise machine utilizes a mechanical brake to provide the principal resistance. A dynamoelectric machine has its rotor connected to the flywheel of the exercise machine and its stator rotatably mounted to the apparatus frame and connected to the actuation input of the mechanical brake. The torque applied between the rotor and stator of the dynamoelectric machine tends to turn the stator and thus actuates the mechanical brake. A control system is arranged to control the current flow through the dynamoelectric machine and thereby control actuation of the brake. This allows a small dynamoelectric machine to effectively control a very large resistance. The dynamoelectric machine may also be used as a motor to drive the apparatus. Thus, the control system can actuate the dynamoelectric machine either to apply drag or to drive the apparatus thereby provided through constant speed operation.