Controlling access to a stationary exercise machine. In one aspect of the disclosure, a method may include establishing one or more authorized users of a stationary exercise machine having one or more moveable members, automatically locking the one or more moveable members of the stationary exercise machine, and receiving a request to perform a workout on the stationary exercise machine. In response to the receiving of the request to perform the workout on the stationary exercise machine, the method may include automatically determining whether any of the one or more authorized users is proximate to the stationary exercise machine. In response to automatically determining that one of the one or more authorized users is proximate to the stationary exercise machine, the method may include automatically unlocking the one or more moveable members of the stationary exercise machine to enable the workout to be performed on the stationary exercise machine.