The Entertrainer

The Entertrainer is a heart rate activated remote control. You only need to watch the TV and keep your heart rate within the target range. If the volume begins to drop – you need to work harder. If you do not re-acquire your target, the volume will continue to drop and the TV will eventually turn off. Conversely, if you work too hard the volume level will increase, prompting you to slow down!

Source: The Entertrainer