HeartRacer is a light, portable tv-based game that helps a player lose weight while watching tv!
HeartRacer works by manipulating a user's heart rate into the optimal zone for losing weight and improving cardiovascular health. Creatures appear on-screen to obscure the player's view of the tv. Only punching various parts of the bag will cause the creatures to disappear. If a player's heart rate is suitably high, the creatures do not reappear. If the heart rate dips, they return, causing a player to keep their heart rate in a weight loss zone throughout their tv or movie.
HeartRacer is a prototype using pressure sensors, Arduino microcontrollers with the Video Experimenter shield, and a Polar heart rate sensor. You can read more about the development process here.