Described is a motivational fitness device, which controls the audio output of a television or audio component in response to the heart rate. The user must exercise in their specific heart rate target training range to keep their entertainment device turned on at an enjoyable volume. A heart rate sensing device relays heart rate to a processor unit. The processor receives and compares the user's heart rate to the specified target range and sends control signals (or not) to the entertainment device. If the user's heart rate drops below the target range, the volume of the audio output of their entertainment device will gradually decrease until the user reacquires their target. Conversely, if the user is exercising too vigorously, the volume will increase, motivating the user to reacquire their target heart rate range.